yamaha yz80 problems

[k14]

My cousin got a yz80 for christmas and he is really guttered at the moment. It doesnt go

Apparantly it was going fine until yesterday when it just stopped working while he was riding it. I went and had a look at it this morning and couldn't seem to find the problem. It will start but will just run for about 5-10 seconds and then just stop. Doesn't matter what i did it didn't want to go.

I took the carb off and gave that a clean (although it was clean as already). Took the fuel filter out and gave that a clean aswell. Pulled the filter off and seemed to be alright. Cleaned the plug aswell.

Could be that he wasnt riding it hard enough (it is his first bike), and the plug could be stuffed, but if not then I don't know what it is.

Anyone got any ideas?

[Motu]

Sounds like it's not getting fuel - pull the fuel hose from the tap off the carb and turn the gas on,it should run out pretty fast.Take the float bowl off if you can,if not unscrew the float bowl drain,watch the flow.It's either not getting enough to the carb,or not enough into the bowl,find out which...then clean the tap or set the float level.Put in a new plug too.

[k14]

Done some of that except the plug and draining the float bowl.

I thought it was a case of not enough fuel aswell. I took the fuel line off and opened the tap and the fuel seemed to come out fairly quickly. Took the float bowl off and cleaned out the main jet, not the idle one though, but i doubt it would be that. The inside of the float bowl and the main jet didnt have any crap whatsoever in it.

Will try a new plug in it and see what happens then.

[Racey Rider]

I could come and have a look at it tomorrow or Saturday if your in NP.
I have a bit of mechanical background, and sometimes it just takes a new set of eyes to see the problem.

[k14]

Thanks for the offer, but I will probably pass. They were very hesitant on letting me even touch it, so I don't think it would go down well letting another guy come and look at it.

They are probably going to take it to the shop now, not my bike and I have tried to fix it. Its probably really simple, lol. I will throw a new plug in and if that doesn't fix it then to the shop it goes.

[k14]

Managed to fix it just before, turned out to be alot more simple than what we were thinking. Works sweet now with a new plug.

Damn, this is the first motox bike I have ridden (only road bikes previously), but it is so damn powerful. Lifts the front wheel in first no problems. The powerband is leathal, pratically an on/off switch. Think I will be going round to "service" it quite regularly.

[Wellyman]

Yea YZ80's are suicidal and do need a bit more work the the four strokes so you may have a new job

[crazyxr250rider]

Yea YZ80's are suicidal and do need a bit more work the the four strokes so you may have a new job

But not as suicidal as YZF426`s woah moma

[Bert]

Managed to fix it just before, turned out to be alot more simple than what we were thinking. Works sweet now with a new plug.

Damn, this is the first motox bike I have ridden (only road bikes previously), but it is so damn powerful. Lifts the front wheel in first no problems. The powerband is leathal, pratically an on/off switch. Think I will be going round to "service" it quite regularly.

lots of fun... i still think they would make great bucket motors (stock)

[Sensei]

My old YZ490 was most Excellent

[cheese]

you have to ride the MX'rs quite hard so if he is going to slow it will foul plugs alot (like me) other way to go is to run hotter plugs. but only change one number at a time and inspect you plug after each ride. If it's white your too hot or lean, if it's all black and greasy, your too rich.

[Wellyman]

Jetting is a problem. try cleaning out all the carbs and changing plugs is a good way to start.
WM