soonerdude77
07-21-2008, 01:08 PM
Sorry for having to ask questions on the first post, and it being somewhat lengthy but I'm trying to give all the details so maybe someone can help me.
I'm in the process of buying a "project" '00 400EX from a friend of mine but we can't get it started. The confusing part is that I was there when he rode it into his garage and we tore the top end down. We knew it had some piston/cylinder damage to begin with due the clouds of smoke and oil being puked out through the exhaust but after looking at the piston it defied all logic by running in the first place much less not being locked up(cracked skirt, oil rings glazed over with aluminum, etc.) So we got a mild bore(402), new piston, gaskets and went back to a stock cam since the WB one that was in it was toast. We didn't want to trust ourselves with putting it all back together so we had someone who knows what he's doing put it together for us.
Now when we try to start it, the motor turns over and thumps but it just won't fire up and run. We've checked for spark, checked the timing, tried spraying gas/ether in the carb, checked the valves, and cleaned the carb, but we can't get anything more than the thumps. The only thing we changed with the rebuild that I can see causing the problem would be going to the milder cam but I don't know why that would cause a problem. Any suggestions?
I'm in the process of buying a "project" '00 400EX from a friend of mine but we can't get it started. The confusing part is that I was there when he rode it into his garage and we tore the top end down. We knew it had some piston/cylinder damage to begin with due the clouds of smoke and oil being puked out through the exhaust but after looking at the piston it defied all logic by running in the first place much less not being locked up(cracked skirt, oil rings glazed over with aluminum, etc.) So we got a mild bore(402), new piston, gaskets and went back to a stock cam since the WB one that was in it was toast. We didn't want to trust ourselves with putting it all back together so we had someone who knows what he's doing put it together for us.
Now when we try to start it, the motor turns over and thumps but it just won't fire up and run. We've checked for spark, checked the timing, tried spraying gas/ether in the carb, checked the valves, and cleaned the carb, but we can't get anything more than the thumps. The only thing we changed with the rebuild that I can see causing the problem would be going to the milder cam but I don't know why that would cause a problem. Any suggestions?