Went for the first ride today after buying and it ran for about 15 minutes then suddenly nosed over and died as if it locked up. Being my scrambler did this years ago i assumed the worst and got off and stared...

I let it sit for a couple of minutes and cranked it up and it started...weakly but started. I'm quite a ways away from the house so i start limping it back home and it ran for a couple of minutes and died again. Called my neighbor and he pulled me back home and once there i told him it wouldn't start and to prove it i cranked it over and it started up again...sounds a little weak and will not idle.

Some info....

Each time it died it was ratteling when it did.

Its running race gas with Bel-ray in the oil tank.

Ive never saw this bike smoke at all....but the oil level is lower than it was.

What do you think????

Does the engine have to come off to top end it if needed?

 

Check compression first. Sounds like you scored the piston to me.

 

any more takers?

 

Unless the motor has alot higher compression ratio than stock that race gas is doing more harm than good.

 

yea, my best guess would be the race gas hurt the piston and rings.

 

its VP brand fuel with a motor octane of 107, Recommended for two strokes up to 12:1

I sell this stuff to guys all day long and never had any issues

 

107 octane recommended for 2 strokes up to 12:1?I think you got that backwards,107 would'nt be needed unless you're over 12:1.That motor probably won't even reach operating temps with that high of octane unless it has a shaved head and a big bore or stroker crank.

 

Straight from VP racing website...
" Formulated for use in naturally aspirated engines with CRs up to approximately 12:1-13:1. Works well in 2-strokes. Good lower cost alternative.

* Color: Purple
* Motor Octane 107"

We are the VP racing fuels dealer for our area and we get tons of dirtbikes and ATV'ers and ths is what they ask for...hurting the engines, im not sure...


look, i don't want to get into a debate about the fuel, i respect all answers to my questions and will look at all the info i can get. It was running fine and I noticed it was taking a little more throttle to keep moving and then it rattled, nosed over and died. I'm guessing that it started to seize as after it cooled it restarted.

So....is there a way to manually check the oil injection?

If it needs to come apart, can i do the top end without removing the engine?

 

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If it's a top end failure you should be able to do it without removing the engine.Sometimes the pto or mag side seals fail causing it to suck air and lean out so check those also.For checking the oil injection I would pull the line off the pressure side of the oil pump and hold the throttle wide open while pulling the recoil rope and watch for oil coming out of the hose(kill switch off of course).That's how I bleed the oil lines on sleds after a rebuild.