Bike won't restart after stalling

[Andrew06]

I have a Yamaha Fino (110cc auto-scooter). It seems to start perfectly but can stall thirty or so seconds later, then it refuses to restart. It makes all the right noises but just doesn't seem to catch, kick starting it at this point has about 50% success. It seems leaving it alone for 5 mins or so and then trying is the only solution and then it will always start first time. I have had a new battery, new spark plug, air filter, and the carb cleaned but didn't help. The bike has only done 7,000 miles and is 2 years old.


Thanks in advance for any help.

A

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[Easy Rider]

but can stall thirty or so seconds later, then it refuses to restart.

Restricted fuel flow......or a tank vent plugged.

I assume it has an "automatic" choke ???

If it has a manual choke, you may be opening the choke too soon.l

[Andrew06]

It has a manual choke but I never have to use it to start the bike.

[hondanewbie]

Try the choke first!(it's cold now). Is this a 2storke scooter? I've ridden LOTS of scooters, and fixed even more. Could be your piston rings need changing. When it won't restart, check the compression. If you don't have a compression tester, add a little 2stroke oil to the chamber and try again. If it starts after that, then it's piston rings most likely. (If it's a 4 stroke, please ignore all that

[Easy Rider]

It has a manual choke but I never have to use it to start the bike.

When it stalls out soon after starting, that is an excellent clue that it NEEDS some choke until it warms up.
That may be your only problem.

[Andrew06]

When it stalls out soon after starting, that is an excellent clue that it NEEDS some choke until it warms up.
That may be your only problem.

I agree that the use of the choke would help stop the bike stalling but wouldn't explain why it refuses to restart? I am living in South East Asia so temperatures here are Never cold and currently not wet at all. It mainly happens to my wife as she doesn't really rev it when she first gets on, but its a major worry when it happens to her late at night. A two year old bike with very few miles shouldn't run like this.

Andrew

[hondanewbie]

I agree that the use of the choke would help stop the bike stalling but wouldn't explain why it refuses to restart? I am living in South East Asia so temperatures here are Never cold and currently not wet at all. It mainly happens to my wife as she doesn't really rev it when she first gets on, but its a major worry when it happens to her late at night. A two year old bike with very few miles shouldn't run like this.Andrew

Compression, bad spark plugs, you just have to start ruling things out. If you try the choke, it may solve your problem. Not using it, you might create a fuel issue that either draining the carb, or letting it stand for an extended period of time will solve. If at least try the choke

[Easy Rider]

I agree that the use of the choke would help stop the bike stalling but wouldn't explain why it refuses to restart?

Yes, it could.......especially if you also don't use the choke for the re-start attempt either.

For an engine, 70F is "cold".

Did I say that a dose of a good carb cleaner might help ??

[Andrew06]

This occurs very often and I have tried it every which way after it stalls. Choke on, Choke off the only way that seems to work is leaving it alone for at least 5 mins.

[Easy Rider]

This occurs very often and I have tried it every which way after it stalls. Choke on, Choke off the only way that seems to work is leaving it alone for at least 5 mins.

I still think that proper choke useage would mostly solve the problem but if you insist on looking for something to "fix" check the fuel flow, including the tank venting.

Have you checked or changed the plugs lately ??

[Andrew06]

Can you explain in detail how I can correctly use the choke? This one in question slids from right to left.

In my opening post I stated what works I had already undertaken, plugs done.

Thanks

[Easy Rider]

Can you explain in detail how I can correctly use the choke?

ON and OFF are the best terms; it is up to you to figure out which way that is with your given choke control.

Turn it fully ON. Leave the throttle alone. Start engine.

It probably will run too fast after a few seconds. Move the choke toward OFF until the engine speed comes down to just a little bit faster than normal idle.

Let it run like that for a bit.....maybe 30 seconds.......or until the engine speeds up again and then reduce it toward OFF a bit more.

Usually after the second adjustment, you should be able to rev the engine a bit and ride if you really need to.

After a couple of minutes, the choke should be very close to OFF and the engine stable and rev-able.
If not, you have a carb problem or the idle jets are adjusted too lean......or there is an air leak around the intake or a hole in the filter or an aftermarket filter has been installed.

[limitedbyfourkawiby2]

I would spray some wd-40/starting fluid/carb cleaner (with wd-40 being the best) around the intake to check for leaks while the motor is running. be careful so the engine doesn't catch on fire(starting fluid), the intake rubber or gaskets dont melt(carburetor cleaner), or the wd-40 doesn't start on fire or smoke off your hot engine. that is my next guess after using the choke.

[kartl]

It could be a dirty fuel or clog fuel system.

[Aussie Steve]

Check the mentioned things... esp the tank vent... as it sounds very like fuel starvation...might even be the float height.

If it is a two stroke then check the muffler is not carboned up...common problem with two strokes. The low mileage over two years may actually be the cause...never ridden long enough to burn off the carbon. Also remove the header and check the exhaust port for carbon build up.

If all of these are beyond your scope just try running it with the muffler removed to see if this helps.

Good luck