Scooter won't rev

The scooter ran okay but was a little slow and struggled with hills but it had been sat for about 18 months. It is a JL50QT-5 and I'm guessing the drive belt is well overdue.

However in the meantime I thought I wold derestrict it by adjusting the bolt in the carburettor. All done, start her up and everything seems fine. Take it for a test ride and find it won't rev anything other enough to pull away and then won't rev any higher ad tries to stall.

I wonder if I have damaged the carburettor?

Fuel is coming out the supply pipe so that seems fine. There don't appear to be any air leaks. I just don't know what else to do?

 

Yes, tried that, checked needle, checked float, the carburettor seems fine. Might get some carb cleaner and see if that clears the problem, guess dirt or something could have got into the jets?

 

Drain the carb float bowl (should be a little brass screw right at the bottom) and see if any water or crap comes out of it, as water can affect the float bowl's function, by not allowing it to fall properly. I'd also syphon some fuel out of the tank and put some fresh Super Unleaded fuel in it, as the stuff in there now will have gone stale. Modern fuels don't store well for long periods. You can dilute the old fuel as you top up with new stuff to use it up and the Super Unleaded will compensate for the stale stuff.

 

Its got new petrol and I have opened the bowl and it all appears good with the float seeming to work.

 

I wonder if the needle isn't rising now reducing the air into the carb, would that cause loss of revs?

 

Did you remove the needle from the throttle slide? If you haven't touched it, then it's OK.

 

The needle came out when the spring popped up.

 

Was there a plastic retaining ring, that sat above the needle and that the return spring located into? Did you put the needle back first, before the clip and spring?

It could equally be a W shaped spring clip that retains the needle.

 

Loads of parts available for this little scoot at CMPO. It's in their listings so you'll have no problem with getting anything for it.

 

I was expecting a ring but I never saw one

 

If the carb was the only thing you touched/adjusted, then i would go back to that and have another look. I have one of your carbs on the shelfso if i remember i'll have a look tomorrow and see if it has a needle retainer.

 

That would be great, really puzzled and frustrated as I can't ride it like this.

 

Inside the diaphragm is a white plastic piece with a small spring which was under the main spring, the needle was loose in the jet.

 

Should the needle be connected to the bottom of the white plastic part?

 

The needle should be the first thing you put in before anything else, so that it's sat on the bottom. then add the small spring, the diaphragm and the large spring in that order (I'm pretty sure that's correct). That should sort it.

If you aren't sure, take a photo and let's have a look at the parts.

 

That's how it is in, will see about taking it off again tomorrow and photographing it.

 

Check your air filter too. Mine had been stood for a while when I bought it and didn't go too well.
The air filter was really dirty and in need of changing which was affecting the performance.
A new air filter can make all the difference.
Also, try fitting a new main jet in case it's got clogged up?

 

Air filter has been replaced along with oil and filter.

Think I'm going to get some carb cleaner today and see what that does...

 

Also noticed that the HT lead is split and the wire exposed and gave me a little shock when I knocked it but that must have been like it before so I don't think this is the problem.

 

http://i39.photobucket.com/albums/e...9EDB985B-660-000000BD1D9F6EC4_zpsbb7ca1d1.mp4

Engine running, would have expected the diaphragm to raise higher up?



Order the parts were in the carb...