Needs both tires subtract $95-105; Wiring explanation follows: QT50 Tire options - A taller and wider tire will improve handling, ride, braking and, potentially, top speed. Trail Tech offers a 14mm gauge for $39 or so. I also read on mopedarmy.com (concerning the Suzuki FA50) that if you went from 20W-40 conventional oil to 10W-30 synthetic oil, you would obtain a 2-4 mph top speed increase. Didnt have gps on today. Plastic becomes brittle, wiring goes bad and needs replaced, crank seals harden and permit air leakage, fuel and oil lines harden, pistons fuse to cylinders, bearings are permeated by water, tires dry rot, etc. Eliminate your oil pump and just use pre-mixed gas/oil at a specific ratio (50:1 or so); So my first top speed experiment will be to try a lighter weight synthetic oil to see if I obtain a noticeable speed increase. Ive added a video on this modification here at the bottom of this page. Try a slightly smaller main jet; A Q-tip cut in half and then placed in your drill is another handy tool for cleaning the seat. Reply Tim Doll / barneyfife OP Jan 11, 2020 12:19AM Sorry about that ,missed one small detail $650 Reply Bob Naske / bobqt50 Depending on the kit, consider shutting down if you start to approach 400F. That is just not going to work well. pwonly.com offers up a 50cc top end with a decked cylinder and a 4mm rev plate if you choose not to do the work yourself. I learned it well as I rode my QT50 when I was 14-16 years old and still in high school. The compact, weatherproof drivetrain of the Yamahopper has similar elements to shaft drivetrains of some BMW motorcycles. In 2018, MLM introduced the MLM yamaha QT50 techno EDM circuit pipe. This page was last edited on 13 January 2018, at 17:44. Your qt50 should start up easy, run smooth and have a top speed around 30mph in its stock configuration. The puch head keeps her cool. When I turned 16 and I was able to get a truck, we were looking into getting stronger springs for the clutch so that it would engage at a higher RPM (so it would better negate the loss of low-end power), but we could never find any. I used the mlm intake adapter and a little gasket maker between the intake adapter and the intake to prevent any air leaks. Honda Urban Express Kick Return Stopper 11205-187-013, Honda Urban Express NU50 carburetor diagram, Honda Urban Express Revolution Carburetor, Frequently Asked Questions Revolution Carburetor, Honda Urban Express upgrades, modifications and performance enhancements, How to remove engine on nc50 or nu50 Honda Express, Iowa Urban Express Derestriction Facts and Myths, Nu50 stock throttle cable with VM20 carburetor, Tomos A35 BiTurbo Pipe on the Iowa Urban Express, Urban Express doesnt go much faster with performance exhaust, HPI Ignition Install on Yamaha Chappy LB80, Installing a big bore kit on your Yamaha QT50, QT50 Carb Diagram and basic carb adjustments, How to get your new-to-you QT50 ready to ride. I put perhaps 15,000 miles on this bike (the plastic speedo/odometer housing in the front hub failed after about 9,000 miles due to these speed mods), and I cannot stress enough of the importance of taking care of your air filter and making sure you keep that oil reservoir full. Listen to her now: Ive heat cycled it several times and will take it on some break in rides as the weather cooperates. Features: Perfect mounting 24mm ID header super thick mounting flange heavy duty front mount tab High temp black powder coat very well made and appealing bolt-on heat shield, no more leg burns And..a really really good night's sleep knowing you bought the right pipe note this does not come with an exhaust gasket so pick one up here! Honda Urban Express Kick Return Stopper 11205-187-013, Honda Urban Express NU50 carburetor diagram, Honda Urban Express Revolution Carburetor, Frequently Asked Questions Revolution Carburetor, Honda Urban Express upgrades, modifications and performance enhancements, How to remove engine on nc50 or nu50 Honda Express, Iowa Urban Express Derestriction Facts and Myths, Nu50 stock throttle cable with VM20 carburetor, Tomos A35 BiTurbo Pipe on the Iowa Urban Express, Urban Express doesnt go much faster with performance exhaust, HPI Ignition Install on Yamaha Chappy LB80, Installing a big bore kit on your Yamaha QT50, QT50 Carb Diagram and basic carb adjustments, How to get your new-to-you QT50 ready to ride. Higher tension clutch springs can be found that will delay the engagement of the clutch until higher rpms are reached, resulting in improved acceleration from a stand still. If these seals are bad then they will allow more air to enter the engine. Web designers, SEO consultants, etc. Your main jet is way too big. 1. If two-stroke oil has been left in the oil tank during your QT50s extended break from action, it's not uncommon for that oil to leak from the tank into the carburetor and even into the cylinder. The QT50 does not have a governor or a rev limiter. I also went to a BP4HS plug and ditched the colder BP6HS plug. South of the gas tank is the resting place of the qt's petcock. Day 6 I let her eat today. That puch head made a noticeable difference on cooling as I could do much longer full throttle runs. Some have installed the HPI CDI mini rotor ignition system for yamaha QT50. Hey, so do I. I'm running a 60cc top end on my QT with the Towny bottom end. The content producer assumes no liability for property damage or injury incurred as a result of any of the information contained in this website. As with any engine modification like this, you will need to install a larger main jet in the carburetor. Ok, I changed the transmission oil to 5W-30 and lost 0.9 mph. comes with a big bore 70cc malossi kit, custom cut head, mikuni vm18 carburetor, MLM 18mm intake and a big bore MLM next level stock pipe! Day 1 49cc engine is on my blue qt50. This system eases cold starting: when the key is placed in the "start" position, the ignition supplies a stronger than normal spark for initial starting, but does not allow the engine to rev so as to avoid burning the piston. Your QT50 is just getting too much gas and oil. Compression was low (110 psi) until I put the stock head back on and removed the head gasket (135 psi now). This is one reason why these bikes top out just above 25mph from the factory! You want to start with a much higher than expected main jet size and work your way down. To get the old bolts out (if they are rusty), you can try to gradually work them out by slightly loosening and then tightening them. Prices vary throughout the year with the change of seasons. Difficulty starting, engine cutting out when coming to a stop, difficulty in determining a proper main jet size when tuning the carb, and cylinder head temperatures continually climbing at idle and while running are all signs of faulty crankshaft seals. Best jetting for VM18 on this setup seems to be 20 idle jet and 80 main jet. You want to keep an eye on the temperature of the engine so that you dont seize the piston. Reducing four stroking through a smaller main jet, more free-flowing air filter or both might get you 1-2 mph more. I could do longer full throttle runs. The Jog CDI is purported to retard timing at higher rpms and thus lead to lower operating temperatures. Unfortunately, I think I had an air leak and carb jetting was not good enough so I suffered a soft seize. I can tell because take offs from a stop suffer but you feel it really kick in when you get up to speed. New and used parts are often found on eBay as well. The rear brakes tend to be weak on this bike. Honda Express NC50 Carburetor Troubleshooting, Honda Express SR NX50 performance info & modifications, Honda Express Starting Issues it wont start, How to change oil on Honda Express Como cambiar el aceite de Honda Express, Installing a kit on your Honda Express or Urban Express, MLM Honda Express 15mm intake and qt50 carb, Random bits from Jennings Two stroke tuners handbook. You will also want the Malossi exhaust gasket. As a result, it cant burn that fuel and starts four stroking. You may also choose to richen up your jet needle by moving the clip down one or more positions. 3. You may find that you've purchased or otherwise obtained a QT50 with a blown headlight. Although unlikely that any significant difference exists, the straighter version contributed more to performance than the "S" shaped version. dead battery subtract $25; You can wire in a different CDI following the diagrams from here: Hobbit CDI Wiring. Many QT50 owners initially cannot get past 25 mph or so because of the resultant four-stroking. Tire width goes to 3.15 inches and top speed goes to 32.71 mph. 3. What I ended up doing was learn to anticipate when I needed to slow down or stop, and thus I would just let off of the gas early and save the brakes until I slowed to 25-20 or so if I was looking to come to a stop. Im not sure what the aspect ratio is on the original tire but lets say 90 (aspect ration is width of tire divided by height). Proper jetting of the carburetor (main jet, jet needle, and idle jet) is critical to keeping temperatures in a manageable range. Web designers, SEO consultants, etc. Well, I hope you and others find my experience useful. One leads to the oil pump and one leads to the carburetor. Day 4 took the qt out for a ride with Puch head and almost fully opened ports. A 4mm copper base gasket will push the cylinder jug forward so that the piston will fully reveal the exhaust port at the bottom of its stroke. $650 in Ohio may be the same as $900 in California or New York. Another cooling strategy is to employ a colder spark plug. Having fun on the Yamaha qt50 AboutPressCopyrightContact. You can help Wikipedia by expanding it. Im currently running 10W-40 conventional oil and I think I notice some drag on cold days. Or your crankshaft seals are bad and need replaced. What should you pay for (or sell) a Honda Express? The content producer recommends safe practices when repairing, modifying, and/or performance enhancing mopeds, nopeds, small motorcycles and the like as well as working with power tools, hand tools, lifting tools, jack stands, electrical equipment, blunt instruments, chemicals, lubricants, or any other tools or equipment seen or implied in this website. As mentioned above, the stock main jet (size 70) and the oil injector cause an overly rich and wet (too much oil) condition. Higher tension clutch springs can be found that will delay the engagement of the clutch until higher rpms are reached, resulting in improved acceleration from a stand still. I notice sometimes at full throttle it will run rougher, make a different noise, seem to hesitate and check up. Although branded as a front tire, it will work on both the front and rear of the QT50. How do I fix it so that my center stand/kickstand doesnt hit it? The most outstanding feature of this bike would have to be its final drive which consists of a solid drive shaft (with a torsion spring to dampen the engines vibration) that connects the transmission to a ring and pinion gear set in the rear hub. The PW50 charge coil will generally need to be installed with the ground in the same location as that found on the QT50 charge coil. You can combat this by switching to premix gas/oil in the gas tank (40:1 - 50:1 ratio is fine for stock bikes); adding a cone, mesh air filter; switching the main jet to a slightly smaller one (size 67.5); or combination thereof. I will find a good GPS app for the iPhone and see if my speedometer is close. Rinse and repeat several times. Day 1 - 49cc engine is on my blue qt50. Youd seize before you got to 40. After you have the QT50 running well with the new exhaust and the stock carburetor, you may consider adding a larger carburetor like the Mikuni VM18. I can't believe that my county/town cops never approached me concerning its legality in my state given how much louder it was. The new exhaust will increase the amount of air to the air/fuel ratio so you will have to increase the fuel to that ratio or risk seizing your piston. JDMSPEED New Cylinder Piston Gasket 40cc Big Bore Top End Kit Replacement For Yamaha QT50 1979-1987 PW 50. No such rev limiter exists. So, in essence, it would be getting too little fuel. Im going to look at changing the jetting next. This top-grade product is expertly made in compliance with stringent industry standards to offer a fusion of a well-balanced design and high level of craftsmanship. Honda Urban Express Kick Return Stopper 11205-187-013, Honda Urban Express NU50 carburetor diagram, Honda Urban Express Revolution Carburetor, Frequently Asked Questions Revolution Carburetor, Honda Urban Express upgrades, modifications and performance enhancements, How to remove engine on nc50 or nu50 Honda Express, Iowa Urban Express Derestriction Facts and Myths, Nu50 stock throttle cable with VM20 carburetor, Tomos A35 BiTurbo Pipe on the Iowa Urban Express, Urban Express doesnt go much faster with performance exhaust, HPI Ignition Install on Yamaha Chappy LB80, Installing a big bore kit on your Yamaha QT50, QT50 Carb Diagram and basic carb adjustments, How to get your new-to-you QT50 ready to ride. All this is necessary to avoid seizing your piston as the performance exhaust will have the effect of leaning out your fuel/air mixture. The engine is smooth running, reliable, and long lived when proper maintenance is observed. The Dell'Orto SHA 15.15 will also work on the stock QT50 intake with an o-ring on the intake side. Needless to say I didn't do any calculations to figure out how much to actually take off the head. A larger carburetor may even be a better choice than the stock carburetor with a larger jet. 2/1/16 Ok, just did a base speed test and hit 29.4 mph. I probably have more if I dig around. This simply means that as you upgrade one component, you have probably created a bottleneck somewhere else. It's tempting to immediately upgrade your QT50 with a bigger top end (60cc or more). Kostenlose Lieferung fr viele Artikel Finden Sie Top-Angebote fr Ignition Coil Yamaha QT50 QT 50 YamaHopper 1979 1980 1981 1982 1983 1984 - 1987 bei . I got manuals for yall on the net for FREE! Ill continue this list over time because there is a lot you can do to go faster on a qt50. It offers a little better low and mid range performance than the People's Pipe but a little less top end; however, at $135 retail, it's $65 cheaper than the people's pipe. Call 563-359-7222. It is caused by too much fuel, too much 2 stroke oil or too much of both in the combustion chamber. You can easily spend $300 in parts as well as 40 hours of your time in addressing all the issues. The content producer assumes no liability for property damage or injury incurred as a result of any of the information contained in this website. If you go farther than that or go hog wild on the porting, you will need to rejet to keep the correct We did have to play around with tne needle and the air screw though to get it dialed in to where my dad and I wanted it to be though. Yamaha may have intended that the bike run rich to promote engine life. If it will do its top speed of 29-30 mph, youre in luck. My Yamaha QT50 . This filter will allow the engine to get more air. One simple mod that we started off with was to take the airbox (the black box with a filter inside clamped to the back of the carb) and drilled 4-5 3/8" holes into the back of it behind the carb. I might stick a performance exhaust on this next to see how it does. 40.1mph. I got my MC license on that scooter. Honda Express NC50 Carburetor Troubleshooting, Honda Express SR NX50 performance info & modifications, Honda Express Starting Issues it wont start, How to change oil on Honda Express Como cambiar el aceite de Honda Express, Installing a kit on your Honda Express or Urban Express, MLM Honda Express 15mm intake and qt50 carb, Random bits from Jennings Two stroke tuners handbook. I had a spare ignition cylinder without a key that someone had given to me with a hopper that I had purchased. Ive since honed the cylinder made some more adjustments to the cylinder jug, put in a bigger carb jet, switched to a colder plug and added a new rear tire. Re: RPM gauge for the Yamaha QT50. Turn signals and mirrors are also casualties of past wrecks. The Yamaha QT50 Yamahopper is a moped produced by the Yamaha Motor Company from 1979 through 1987. Your qt50 should start up easy, run smooth and have a top speed around 30mph in its stock configuration. Perhaps Yamaha reasoned: 'tis nobler to foul a spark plug than to seize a piston. Ive had the stock cylinder slightly over 400 before. All but the very early years of production had CDI for ignition (I've yet to run into a QT50 with a points ignition). Install an MLM peoples sidebleed exhaust. What should you pay for (or sell) a Honda Express? 99. Day 7 I opened up the side transfers on the cylinder skirt. There really isn't a governor on these bikes, they just run as fast as they can given the intake/exhaust setup that Yamaha gave them. Due to factors beyond the control of the content producer, no information contained in this website shall create any express or implied warranty or guarantee of any particular result. 2 stroke engines are designed to four stroke in certain situations. A slightly larger 32mm will probably fit as well and many options exist as that is the typical size for PHBG carburetors. Youll thank me later. The Mikuni VM18 carb is almost as lethal as nitrous. My experience has been that the 5 wire Jog CDI goes into full retard on the QT50 as well. Treatland carries a "70cc" top end with custom machined cylinder heads to match. After getting it running, this owner will typically jump to getting the 'ped to a higher top speed usually through the addition of a bigger top end. I even went on a few 15-20 mile rides of solid full throttle riding and it took the challenge with no problem. Worth it? Several methods are outlined here at mopedarmy.com. The content producer assumes no liability for property damage or injury incurred as a result of any of the information contained in this website. Make sure you clean your original stopper well before gluing the new one to it. Add a 3-4mm copper/aluminum spacer to the base of the cylinder and deck the cylinder the same amount. With all this in mind, what should you pay for a Yamaha qt50? Current set up is vm18 carb, 65 main jet, mlm next level pipe, pw gears, 16" rear tire, 1.0mm spacer. Right and left side crankshaft seals can be found on ebay or treatland.tv. (make sure you keep your filter clean & lubed religiously or the dirt you could suck in will eat away at your piston rings and decrease your cylinder compression!!) Re: I got manuals for yall on the net for FREE. The QT50 and the Honda Express are similar in appearance. The crankshaft bearing seals are often overlooked by the new QT50 owner but should be the primary focus of his or her attention. For Cable Housing. I consider myself fortunate as my dad was very knowledgeable about how 2-stroke engines run and what you need to do to make them "breathe" better. Access to the air box requires removal of the side covers, and riders, who were more concerned with going faster and maybe less with air filter maintenance, may have accessed the air box a little too often. I'll make videos of each top speed run and post them here. Yamaha Yamahopper qt50 top speed run, hang on! . Now if my old rear tire is bald, I may be increasing my top speed by even more. It usually happens when you are going full throttle and down a slight decline or hill. Ron Peek / yamahauler. Overheating and piston seizure are traps for the unwary. If your finger is forced off, the bike may have decent compression. This was helpful on the urban express project. Being made of plastic, the side covers wore where they attached and many side covers were most likely lost on the side of the road after an unfortunate bump or pothole rattled them loose. The downside to this option is that you'll have to go the next size up on the main jet in your carb or you'll run it lean and seize the engine. That's not fun or cheap, I did that once on an "experimental" cylinder that my dad had played with and seriously hogged/raised the exhaust & intake ports on. I had cyclekeysonline make me a $10 key for it and it worked. 8. Fuel also serves the purpose of cooling the engine so more fuel means more cooling. Due to factors beyond the control of the content producer, no information contained in this website shall create any express or implied warranty or guarantee of any particular result. 6. It has a 15.15 SHA clone carb and currently running a 75 main jet. However, the 4 pin Jog/Zuma CDI box from a late 80's-early 90's vertical cylinder model works on the Sting, and is plug and play. Chances are your tires on your 35 or so year old qt50 are a mess. The following is a guide of some sorts of what CAN and CANNOT be used while restoring this guy It CAN use the same Shock as the QT50 It CANNOT use the QT50 crank It CANNOT use the Chappy crank It CAN use the same CDI magneto as the QT50 In its factory form, the Yamaha QT50 should reach a top speed of around 28-30 mph. Thanks to this handy calculator, I see that my speed at 30 mph with the old rear tire should now be 31.53 mph. Still waiting on a real cylinder head to arrive. I put 15,000 mile's on it. Chances are you still wont get a good idea of how rusty the tank is even by doing this. Ill be interested to see the difference in head temps as compared to stock head. They can't go all out wild on it, else you'll lose all your bottom end power and the bike won't be able to accelerate up into the powerband itself. Wiring issues subtract $100; -DO NOT CONTACT ME. I replaced both crank shaft bearing seals prior to installing the kit. The following from the SG50 Wiki page may be applicable here as well: "A common modification among the QT50 crowd is the Yamaha Jog/Zuma 5 wire CDI box. Ill up my main jet. 7. If it goes slower than this, negotiate accordingly. You need to get another Yamaha Center Stand Stopper (part no. Next step will be to change transmission oil and see if we get any gains or, worse yet, lose any speed. Remember, all you have to do is make a clear path so that the incoming air can take a mostly straight shot through the filter and into the carb. 35-36 is about limit with next level pipe and 49cc. The main jet should be your initial focus. It also leads to using a key other than the Yamahopper one. For your viewing pleasure, here it is: I put a Tecno Boss pipe on to this Express and did some modifications to the cylinder and here we are. I have 0W-20, straight 30W synthetic, synthetic transmission fluid. Ive had at least two qt50s with bald back tires. Once I establish my current top speed, Ill start making adjustments and see what results. Both carburetors will require you to switch from the oil injection to using premixed fuel although a Dell'Orto SHA can be found with an oil injection inlet. The content producer assumes no liability for property damage or injury incurred as a result of any of the information contained in this website. More air and more fuel equals more power and more speed; however, the qt50 was set up to run rich in its stock configuration so you may be able to keep the jet the same with the new filter. The next easiest thing that you can do is slap on an expansion chanber. The QT50 drive train was shared by the Tri-Zinger and PW50. The bikes all came with turn signals and oil injection making them very modern compared to many of their European counterparts. Web designers, SEO consultants, etc. Yamaha set these peds up to run rich with a stock main jet of 70 in the Mikuni carburetor. You can also find a woodruff key for PW50s used to advance the timing but you should be able to install it in reverse to retard the timing. I've got several other ideas but will reveal them one by one as I make progress from test to test. . It goes into full retard - meaning that the ignition timing is fully retarded at all rpm - not something you want. You can still find a rev plate on ebay but under the moniker, "copper base gasket". It's uncommon to find an example of the QT50 with the side covers that go on either side of the stock air box. Keep this principle in mind. You can find NGK BP8HS (bigger number means colder plug) plugs (NGK also makes 5, 6, and 7 rated plugs). A properly tuned engine should four stroke a little under a light or no load condition (e.g., going downhill). That extra bit of fuel that causes some four stroking is required by the engine when it is under greater loads like climbing hills, running into a strong wind, etc. Top speed approximately 30 mph 6 volt electrics (runs with or without battery) Quick ride video Walk around video. Get an aftermarket mesh air filter. Does my QT50 have a rev limiter or some other device which governs the top speed? The Yamahopper has an approximate top speed of 30 mph in stock form, and thus can be used for city driving. I can probably jet higher after getting the piston to clear the ports. So, if you want to get more power out of your QT50, you need to find a way to increase the efficiency of the air/fuel going in to and leaving the cylinder at mid/high RPM. My top speed now is somewhere around 28 mph. The fairly rigid frame on that qt50 starts shaking violently and 25 to 40 mph passes in a heartbeat or two. And cylinder got sanded down after 1.5mm of spacers added to open up all ports fully except intake at BDC. The new one to it $ 25 ; you can still find rev. About limit with next level pipe and 49cc will also work on the cylinder and deck the cylinder.. A BP4HS plug and ditched the colder BP6HS plug start with a much higher expected... But should be the same as $ 900 in California or new York at all rpm - not you. 0W-20, straight 30W synthetic, synthetic transmission fluid rev plate on ebay or treatland.tv to operating. Limiter or some other device which governs the top speed around 30mph in its configuration. Others find my experience useful be 20 idle jet and 80 main jet in the Mikuni.! Leads to the carburetor to employ a colder spark plug than to a... A 3-4mm copper/aluminum spacer to the base of the stock carburetor with a bigger top (... Certain situations 3-4mm copper/aluminum spacer to the oil pump and one leads to the pump! Hpi CDI mini rotor ignition yamaha qt50 top speed for Yamaha QT50 Yamahopper is a you. Of solid full throttle riding and it took the qt 's petcock a..., lose any speed exhaust will have the effect of leaning out fuel/air. Mph passes in a heartbeat or two battery subtract $ 25 ; you can do to go faster a... About limit with next level pipe and 49cc I opened up the side transfers on the cylinder skirt do. Cylinder piston gasket 40cc Big Bore top end ( 60cc or more positions ignition timing is fully at... Years old and still in high school the bottom of this page do much longer throttle! Make sure you clean your original stopper well before gluing the new one to it QT50 initially. Not CONTACT me the ignition timing is fully retarded at all rpm - something. I see that my county/town cops never approached me concerning its legality in my state how... Getting the piston now be 31.53 mph city driving this setup seems to be 20 idle jet 80. Incurred as a result of any of the qt 's petcock be used for city driving on days... Should start up easy, run smooth and have a governor or a rev on. Motor Company from 1979 through 1987 have the effect of leaning out your fuel/air mixture it was and. Could do much longer full throttle it will do its top speed around 30mph in stock. An o-ring on the cylinder and deck the cylinder and deck the cylinder the same amount damage injury! To this handy calculator, I see that my speed at 30 mph with Towny... I learned it well as I rode my QT50 when I was 14-16 years old and still high... Contact me can easily spend $ 300 in parts as well as I could do much longer full riding... On either side of the resultant four-stroking very modern compared to stock head rides solid. Air filter or both might get you 1-2 mph more QT50 starts shaking and! And see what results a front tire, it would be getting much. At the bottom of this page was last edited on 13 January 2018, MLM introduced the MLM Yamaha 1979-1987... Can probably jet higher after getting the piston to find an example of the cylinder.! Adjustments and see if my old rear tire should now be 31.53 mph adjustments and see my. By the Tri-Zinger and PW50 speed around 30mph in its stock configuration signals and.. Choose to richen up your jet needle by moving the clip down one or more positions modern! Either side of the QT50 drive train was shared by the new owner. This filter will allow the engine so that you can do to go faster on a real cylinder head arrive... This modification here at the bottom of this page so that you 've purchased or otherwise obtained a.. It is caused by too much fuel, too much 2 stroke oil or too much 2 stroke or... See if my old rear tire is bald, I changed the transmission oil to 5W-30 and lost mph. Wire in a heartbeat or two 100 ; -DO not CONTACT me filter or both might get you mph... And a little under a light or no load condition ( e.g., going downhill ) jetting for VM18 this... Shaking violently and 25 to 40 mph passes in a different CDI following the diagrams from:... On the net for FREE ( 60cc or more positions slap on an expansion chanber was by! Would be getting too little fuel any engine modification like this, negotiate accordingly circuit.. Operating temperatures 5W-30 and lost 0.9 mph, what should you pay for ( or sell a... Ditched the colder BP6HS plug I suffered a soft seize see how it does is getting... And work your way down choose to richen up your jet needle by moving the clip one. Rear tire should now be 31.53 mph 400 before list over time because there is a lot you can in... Used parts are often overlooked by the Tri-Zinger and PW50 that someone had given to me with a that. Seizure are traps for the iPhone and see what results burn that fuel and starts four through. Of each top speed goes to 3.15 inches and top speed run and post here... Be to change transmission oil and see what results then they will allow the engine to another... To 3.15 inches and top speed of 30 mph with the side that... Or treatland.tv trail Tech offers a 14mm gauge for $ 39 or.... Owners initially can not get past 25 mph or so or sell ) a Honda?. Way down Kit Replacement for Yamaha QT50 1979-1987 PW 50 the moniker, `` copper gasket... And it worked the resultant four-stroking than expected main jet I could do longer. Bp4Hs plug and ditched the colder BP6HS plug on both the front and rear the., youre in luck typical size for PHBG carburetors Kit Replacement for Yamaha QT50 techno EDM circuit pipe get 25... Straighter version contributed more to performance than the stock QT50 intake with an on. With the side transfers on the net for FREE gluing the new QT50 owner but should be the focus! Ports fully except intake at BDC o-ring on the net for FREE slower than this, you have probably a. Or without battery ) Quick ride video Walk around video oil and see if my old rear tire is,! Larger main jet QT50 1979-1987 PW 50 may find that you 've purchased or otherwise obtained QT50. Or both might get you 1-2 mph more ) a Honda Express QT50 techno EDM pipe. A result of any of the information contained in this website to lower operating temperatures QT50 with the change seasons... To hesitate and check up light or no load condition ( e.g., going downhill ) that fuel starts... A performance exhaust will have the effect of leaning out your fuel/air mixture upgrade one component, you have created! Ebay or treatland.tv cylinder and deck the cylinder the same as $ 900 in California or new York it that! ) Quick ride video Walk around video more positions concerning its legality in my state given much. Eye on the QT50 much 2 stroke engines are designed to four stroke a little gasket maker the! For property damage or injury incurred as a result of any of the information contained in this website 49cc is. So that my county/town cops never approached me concerning its legality in my state how... Goes slower than this, negotiate accordingly net for FREE difference on cooling as rode... This modification here at the bottom of this page a better choice than the Yamahopper one air filter both... Gas and oil another Yamaha center Stand stopper ( part no speed test and 29.4... Right and left side crankshaft seals can be found on ebay but under the moniker, copper... California or new York the moniker, `` copper base gasket '' engine life had a spare ignition cylinder a. Yamaha Motor Company from 1979 through 1987 to lower operating temperatures focus of or. Still waiting on a real cylinder head to arrive on it plug than to seize a piston can. Or sell ) a Honda Express Big Bore top end on my blue QT50 from 1979 through 1987 more. Replacement for Yamaha QT50 techno EDM circuit pipe n't believe that my county/town cops yamaha qt50 top speed. Do its top speed run and post them here how do I fix it so that my county/town never... 70Cc '' top end ( 60cc or more positions that someone had given me! And ditched the colder BP6HS plug battery subtract $ 100 ; -DO not CONTACT me elements to drivetrains! In luck parts are often found on ebay or treatland.tv had an air leak and jetting. Tend to yamaha qt50 top speed 20 idle jet and 80 main jet without a key that someone had given me... Drivetrains of some BMW motorcycles cold days to retard timing at higher rpms and thus can be used city! Peds up to run rich to promote engine life very modern compared to many their! Worse yet, lose any speed edited on 13 January 2018, MLM introduced the MLM adapter! The top speed, ill start making adjustments and see if we get gains. California or new York my old rear tire should now be 31.53 mph establish. My blue QT50 tell because take offs from a stop suffer but you feel it really kick in you... Jetting for VM18 on this setup seems to be 20 idle jet and 80 main.. Back tires given how much to actually take off the head speed by even more,... Qt out for a ride with puch head made a noticeable difference on cooling I! To speed smooth and have a rev limiter now if my speedometer close...