9. With a fully open exhaust port expect gains of 3-4 mph. Or they were taken off, put in some corner of the garage, and were discarded in an annual garage clean-out or couldn't be found to accompany the bike to a new buyer. Ill continue this list over time because there is a lot you can do to go faster on a qt50. That is just not going to work well. A Q-tip cut in half and then placed in your drill is another handy tool for cleaning the seat. The idea behind this was to eliminate the airflow restriction inherent to the design of the airbox itself. Ill continue to work with it before trying a different exhaust. It is a 2 stroke,. Like I said, the stock exhaust is very restrictive and it probably has carbon build-up. In stock configuration, the QT50 will hit about 29-30 mph. Qt50s will sell for less in the fall and winter. This is not a moped since it doesnt have pedals. A rusty tank isnt a deal breaker as you can buy a better used tank on ebay; however, finding one in good condition and in your bikes color may be a challenge. Prices vary throughout the year with the change of seasons. I treat all these as non-runners. 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). Titled and ready to go. If your Yamahopper is difficult to start and smokes excessively after starting, chances are that it's experienced this oil drainage into the carb and beyond. Or fastest delivery Jan 20 - 24 . The header on my stock exhaust is kind of beat up so Im running a double exhaust gasket to seal it up. We'd love to have you join the discussion, but first: This single post is part of a larger thread. 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. The QT50 drive train was shared by the Tri-Zinger and PW50. Once it gets on the pipe though, hang on! Take out the spark plug and shine a light into the cylinder and get an idea of the condition of the top of the piston. Will change jet and try again. Kenda also makes a number of 60/100 x 14" dirt tires that may work as well. The crankshaft bearing seals are often overlooked by the new QT50 owner but should be the primary focus of his or her attention. The QT50 has a sealed beam headlight. So I can compare temps between stock head and puch head. One replacement option is to carefully break out and remove the bulb and cut a slightly bigger opening (if necessary) for a replacement bulb (see the wiki for sealed beam conversion tutorial). Ill repeat that: Prices vary throughout the country so this is just a general guide. a video on this modification here at the bottom of this page. Installing a temperature gauge is always a great idea when you perform modifications like this. Do not use the entire oil package that comes with it to oil the filter. Before you start making performance modifications to your qt50, you should make sure it is running well to begin with. -DO NOT CONTACT ME. The bike has a very compact frame with the center of gravity fairly close to the rear axle giving it a very light feel in turns though it may become somewhat unstable on bumpy roads forcing the rider to shift his or her weight somewhat forward. The Tri-Zinger has a 60cc version of this engine and the cylinder can be installed on the QT50. If you are eventually planning on a bigger top end, go with the VM18. 7. A complete PW50 stator can be had for less than $20. Due to factors beyond the control of the content producer of this website, it cannot guarantee against unauthorized modifications of the information provided or the improper use of the information provided. I talk about this above. Honda Express with tecno boss exhaust and 1.5mm cylinder spacing. Needless to say I didn't do any calculations to figure out how much to actually take off the head. The straighter header will perform better; however, a used QT50 exhaust cannot be had for pennies on ebay and your money may be better spent on a performance exhaust. Some have installed the HPI CDI mini rotor ignition system for yamaha QT50. The Yamaha QT50 Yamahopper was produced by the Yamaha Motor Company from 1979 through 1992. Remplacement pour Yamaha QT50 1979-1987 ; . The seller will make you thicker base gaskets in copper or aluminum. Bent forks such that it pulls hard to one side when riding subtract $85; I can't even begin to count the number of brake drums that I went trough, both front and rear. I notice sometimes at full throttle it will run rougher, make a different noise, seem to hesitate and check up. The IRC NR-77 moped tire - 14 x 70/90 will mount up on the front and rear but fender stay adjustment will be necessary especially to provide clearance in the front. Again the ravage of time has taken its toll on this little device, and it's not uncommon for the OEM petcock to leak in one or more of its three positions. QT50s were popular in the late 1970s and 1980s, These small motorcycles are easy to ride, maintain, and are fuel efficient. QT50 rear shock options - Just about any 320mm mono shock will work to replace the stock shock. In sunshine red with some fresh updates. If you eliminate all four stroking, you may run the risk of seizing your piston. "JDMSPEED New Cylinder Piston Gasket 60cc Big Bore Top End Kit" En lire plus. Compression was low (110 psi) until I put the stock head back on and removed the head gasket (135 psi now). MLM makes a performance exhaust for the QT50, the MLM Yamaha QT50 People's Sidebleed Pipe. 1. 6. 2/1/16 Ok, just did a base speed test and hit 29.4 mph. 2. Caveat: I have found air filters that require a larger main jet so make changes one at a time and observe the results and then proceed from there. Cylinder Piston Gasket Head Set Fits Yamaha PW50 (1981-2018) Bore 40mm. The Jog CDI has five wires as opposed to the QT50's four. Many attribute this wall to some sort of rev limiter. If you have any questions, I'd love to help you out more Well I can tell you how to get some more speed, but it requires some work. Had a high temp of 387F and I wasnt even pushing it hard. At 70mm wide or 2.76 inches, the IRC provides almost an extra half inch of rubber on the road compared to stock 2.25" tires. I never ran into overheating problems, nor did I ever have a mechanical breakdown because I kept up on its maintenence. I may open up the exhaust port and see what that yields with the stock exhaust. The QT50 does not have a governor or a rev limiter. 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. Proper jetting of the carburetor (main jet, jet needle, and idle jet) is critical to keeping temperatures in a manageable range. Available at Brennys Motorcycle Clinic in Bettendorf, Ia. Install a new and bigger rear tire. Another option is to remove the plastic gear from the oil pump and re-install the gearless pump. Day 2 bumped up the main jet slightly to a 67.5 and it took a bit longer for the engine to get heat soaked. Yamaha has tuned the engine to do this in that situation and it represents a compromise. If I recall correctly, my QT50 topped out around 31 on level ground w/ no headwind after this mod alone. 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. Many mistake the low, rough growl as a result of a rev limiter residing in the CDI unit or perhaps elsewhere. To combat this, many riders have eliminated the oil pump and replaced it with an oil plate block-off or an automotive freeze plug. I have a head temp gauge but I have the 2 speed crank case from the towny. 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. The temperature gauge will be your other. I can't believe that my county/town cops never approached me concerning its legality in my state given how much louder it was. This cut down on the brake bill dramatically. Other noteworthy features of the QT50 are its unusual charging and ignition system incorporating a six-volt battery and alternator. 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. It appears to have a retarding curve as well." So it has a 67.5 main jet in it now but a 70 jet is way too rich. We are back up and running. Even if you already have one key, have a spare key made asap. In the end, I was able to get the QT50 consistently up into the 35-40 mph range even on slight uphills, and I was able to almost hit 50 going downhills and also by catching a lucky draft from an SUV on level ground (which was probably one of the dumbest things I've done in my life so far). Heres my Orange 77 Express with SHA style carb which was good for a 2-3 mph increase over stock carb. 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. As with any engine modification like this, you will need to install a larger main jet in the carburetor. I hope compression gets better as the rings seat. When cleaning the carb, focus on the idle jet and the seat where the needle sits. 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. For Cable Housing. Kevlar brake pads and stiffer clutch springs! Be nice to her. A popular choice is the IRC NR-77 moped tire: 14 x 70/90. So, it was less about performance tuning and more about riding technique. Perhaps Yamaha reasoned: 'tis nobler to foul a spark plug than to seize a piston. Almost there. Im going to look at changing the jetting next. Check out the exterior of the carburetor. Generally, if you let off the throttle a little bit, the high pitched whine will return. A slightly larger 32mm will probably fit as well and many options exist as that is the typical size for PHBG carburetors. Of course, this makes me wonder if I can use an IRC NC 77 80/9014 tire. Puch head arrives Monday. 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