Hey guys im new 2 strokes arnt my thing so I was asking for some great information from you guys im 15 and would love to get up and go riding as fast as possible. i have a 1979 yellow yz80 and for the past week its been running great first kick fires like a charm no prob. I was riding it and after about 5min it just died ( whene ever I push start it, it starts half way and runs half way) I cleanded the piston got new head gasket and cleand the carborator along with the reeds. and the air-filter. It still dose the same thing awhile back i kept pushing it half way running and it took off after about 2min and been running good ever sinse it died again. I REALLY NEED YOUR GUYS HELP PLEAS, PLEAS, PLEAS, AND PLEAS HELP ME.

THANK YOU= KEVIN JINES

 

Did you change the plug? If not start there. You need to find out if it's getting too much gas or not enough.

 

YEAH I TRIED A NEW SPARK PLUG ITS NOT GETTING ENOUGH GAS I WOULD SUPOSE BECAUSE WHENE IT DOSE GET MORE THAN ENOUGH GAS IT BOGS REALLY BAD BUT IT IS STILL RUNNING

 

I would have to guess you have an electrical problem. Do you have a good, bright, strong spark?

 

yes the spark is bright white and very strong is the problem just because it is a 2 stroke

 

How did the cylinder walls and piston look when you had the head off? Maybe it's bad gas, or trash or rust in the fuel tank. Did they have a metal tank in '79?

 

Thanks for helping the walls the piston everything exalent i just dont see why it is doing this 2nd time. The dude i got it off of had it set up for raceing fmf exaust im sure of no bore new piston and bottom gasget new carb and fuel tank (plastic) whene i got it, it ran good for about 4months then i just let it sit for about 2months got it out one day got new gas, plug, cleanded carb, and got new oil 5th kick fired right up ran for about 2 days let it sit for a week ran good the next fire then it started to get unreliable out in the country break down for no reason get back it will fire right back up then it started doing what it is doing now i dont know i can show you a pic of it

 

It still sounds like an electrical problem. Electronics will drive you crazy sometimes trying to diagnose them. I'm not real familiar with your engine, but about all you have electrical-wise is a stator and ignition coil. Also I'm not sure how to check them on your bike, but you will need an electrical volt/ohm meter and the specs on what the readings should be.

 

I also forgot to mention whene it did it it was in mud and water and it is still all muddy could that be it should i clean the bike

 

If it cuts off every time it gets wet then yeah, the water is probably getting into the left side of the lower engine where the stator is or the spark plug wire is cracked or the ignition coil has a crack in it. Then when it dries out it will start again.