85 Yamahopper QT 50 spits out gas & oil need h

I have a '85 Yamahopper QT 50, it ran wonderfully for the past 2 years without a problem. Before that, it was garaged for almost 10 years.

One day, the QT 50 starts fast as usual, ran solid for about a minute and as soon as I hit the throttle, the engine sputters & dies out. I started it again, and it ran for about a minute & dies out. The next time I tried, 30 seconds.

The last time, it ran for about 10 seconds and spit about 2 tablespoons of gas out of the muffler. Possibly some oil.

And now it will not run, and it's incredibly hard to start even with starter fluid.

I would really appreciate any suggestions as to how to fix this. I am not sure if it's because the seals were blown out due to age, or gunk in the carb. (I had it cleaned last year)

More information on it:

The QT 50 is in very good condition, everything on it was cleaned including a full carb clean up, and had a new plug put in and everything last year. I have used it often with no problem with the exception on the day it 'died'.

Thank you in advance for any assistance. :o)

Best regards

Re: 85 Yamahopper QT 50 spits out gas & oil ne

try a new spark plug

nick

Re: 85 Yamahopper QT 50 spits out gas & oil ne

Take the muffler off, wash it out with a garden hose from both ends. While it is drying, check the exhaust port for restriction.

Re: 85 Yamahopper QT 50 spits out gas & oil ne

Jason Luther /

yes, get a new plug. they are very touchy.-jason

Re: 85 Yamahopper QT 50 spits out gas & oil ne

yeah, the qt50 is kind of a picky engine

get a new plug, and replace the crank case oil. The screw to drain the oil is a hex screw on the right side of the bike near the bottom. Just put 300 ml of oil in it

nick

Re: 85 Yamahopper QT 50 spits out gas & oil ne

The spark plug is 6 months old (would it make a difference?), and I was using the moped regularly.

Thank you for the advice about the spark plug and cleaning the muffler. I'll do that and see how it goes.

Re: 85 Yamahopper QT 50 spits out gas & oil ne

check the charge of the battery- it may need to be re charged

nick

Re: 85 Yamahopper QT 50 spits out gas & oil ne

Thanks Nick for your suggestions. I will give them a try. I've run the moped without a battery before. That shouldn't affect the moped?

I've got a gas leak right now. It's coming from the carb. I'm not sure why? Would the float play a part in this?

Thanks

Re: 85 Yamahopper QT 50 spits out gas & oil ne

Leon Swarmer /

if the float isn't closing the needle valve, it will cause the carb to overflow. Is it coming out a gasket or out a hole?

Re: 85 Yamahopper QT 50 spits out gas & oil ne

there is a little screw at the bottom of the carb. make sure that the screw is all the way turned in

if that screw is open a little bit, the gas will leak out of that long straw. It is a drain screw

It is all the way at the bottom of the carb, towards the back of the bowl.

--------

As fot he battery, all the battery does is rn your lights, and help it to start. The qt50 has an "electric assist starting system" which makes it easier to start. It will still run with out the battery though. Just watch out that it doesnt blow the headlight.

nick

Re: 85 Yamahopper QT 50 spits out gas & oil ne

also- for the gas leak

make sure that the 4 screws tha thold the bowl on are tight, and that the gasket is not deteriorated.

if the gasketis screwed up, you can buy a new one for a couple dollars from your local yamaha dealer.

Tell them you want the carb bowl gasket for the qt50.

if they dont have it for the qt50- tell them you want it for the pw50 (a little dirt bike that uses the same engine as the qt50-but is still manufactured today)

only do that if you need a new seal

nick

Want to post in this forum? We'd love to have you join the discussion, but first:

Login or Create Account