I did not check for a air leak...I don't know how to do this. If I had a air leak would this have happend before I had the porting done.....when I just had a pipe and a K&N?

Hey Rick I know we will get it back up and running right. And I know it's hard trying to be a doctor over the phone..and I'm glad you will take it easy on the price..

I was out there until 2.00 this morning...I took off the injecter line and made sure the filter was not stopped up.

 

Sounds like detonation to me, from my experience a lean condition will melt the piston dome at the exhaust port and seize the rings loosing virtually all compression. The engine quits running and won't restart. The fact that you also melted the plug makes me think your fuel octane is to low. What was the compression psi and what were you running for fuel? A colder range of spark plug may be in order, I run a 9 in my Scrambler at 165psi on a mix of 110 Sunoco and 93 pump fuel at 40:1. You may consider getting a thermal coating applied to the new piston. Along with the other suggestions you might check the timing as excessive advance will also produce the effects you have.

 

I always use BP 93 fuel, even before any mods was done....I will check to see how hot the plug is, I'm not for sure right now.

 

we had a speaker at our FFA dinner the other night that had some interesting words... ...if it aint broke, have fun and break it anyway

 

I think it is breaking me (money that is) It sucks that it is down and I can't ride, which it's about 20 degrees here....I would not be riding anyway. The money thing is what sucks the most. I'm going to start taking hand outs....I'm going to call it Scrambler 400 Fund...LOL...

 

not riding at 20 degrees?!?!?!?! whats wrong with you? thats when the ride is the best with all the snow. sorry to hear about the machine, it sounds like a really sweet ride. let us know how the repairs go. oh by the way maybe u should talk to rick, bubba, or dennis about gas porting. i recently learned about this and it sounds to be a cheap and easy way to make some power. it involves drilling a series of small holes around the top or the piston and its suposed to put pressure on the rings to seal them to the outside off the bore. it sounds kinda confusing and i dont know much about it so i would ask them, it sounds promising. scott

 

Thanks mudmaster, I have put alot of time and money in it. I should have it back together wensday. If rick can send the parts out today.

 

Hey took some pictures of the piston if you guys want to see it.

 

Notice how it followed the flame travel from the plug towards the exhaust side of the piston. I am sticking to you were lean in the midrange or part throttle. Have you checked the pilot jet ciruit in the carb to make sure a tiny piece of trash didnt get in it?

 

I will check on that tomorrow....I think it was clean, but I will check. I was about half throttle when it happend, so you are probly right. I don't want this to happend again.