Quad help.

[Dklulz]

Okay, to start out the quad is a chinese knock off, baja 50cc for my 6yr old cousin. i'm having troubles getting it started. I have spark all the way to the head. I check all the valves in the carb there opening and fuel is going through. And its still not starting. What else could be wrong? please give you're input its for a x-mas girft!

Thanks

 

[wake_rider]

weak spark, low compression, old fuel, filthy air filter, Chinese quad...

All the above would be where I would begin to search for problems.

 

[Dklulz]

All of the above have been cleaned and checked. still not fireing up tho.

 

[Okiewan]

Is it still a Chinese quad?

 

[jsantapau]

Is it still a Chinese quad?

well it has been cleaned and checked :nener:

 

[rmc_olderthandirt]

I check all the valves in the carb there opening and fuel is going through.
Thanks

I don't understand what you mean by that.

The carburetor has only one "valve" and that is the main throttle. That wouldn't be a problem. What the carburetor has a bunch of are jets and other small passages that can easily be clogged up, especially if the quad had been sitting around unused for a while. If the carburetor is an issue it may need to be disassembled, soaked in a solvent and then have the tiny passages blown out with compressed air. A rebuild kit (gaskets) would be a real good idea, but being a Chinese knock-off getting those kinds of parts could be difficult.

You said you are getting spark "to the head". I am not sure what you mean by that either. If you haven't already, I would recommend changing the plug as it could be fouled not delivering the required spark.

Where you do have valves that could easily be an issue is in the head. If they are out of adjustment they could make starting very difficult. Hopefully they are adjustable. i am guessing that you don't have a manual so knowing what to set them to is an issue. I would take a guess at .006" of gap when at Top Dead Center on the compression stroke.

The basic requirements for an engine to run are air, fuel, compression and spark. To expand on that, the air and fuel have to be in the right ratios or it won't run. The valves have to open and close at the right time in order to have the air/fuel mix in the cylinder. The spark has to happen at the right time.

If the engine simply refuses to run then it could be that the timing of the valves is off (timing chain has jumped) or the ignition timing is off. These will be very hard to check without a repair manual.

Sometimes a stubborn engine can be encouraged to run by some aggressive starting techniques. If it has a clutch I would tow it behind another quad and try to bump start it. I am guessing that it has a centrifugal clutch so that won't work. What might work, however, is to remove the cover over the flywheel (it may have a relatively small plug) to get access to the nut at the end of the crankshaft. Take a large drill motor, chuck up the proper size socket and use the drill motor to spin that engine at 1800 RPM.

Rod

 

[Patman]

What is the compression in PSI? If you don't know you don't know if it will start.
Fresh plug? Pull the filter off until it actually runs (provided it is stored inside).

The honest truth is the engine is disposable unless it was manufactured by Jialing or Lifan.

 

[Matt90GT]

well if you value your kids life, part the thing out on ebay. they are not built safe at all! poor metal qualities, no research into frame geometry and just SCARRY

save up the $ for a japenese quad. Your kids will live longer