- Joined
- Dec 30, 2003
- Messages
- 3,688
There have been some comments regarding this happenning and solutions from carb adjustments to various other ailments. Thought I'd share what I found. My 750 combat has been doing this for more than a year. It's not really that annoying, so didn't dig into it. Recently it started blowing oil out the left exhaust port (leaking around the exhaust nut). Inside the cylinder didn't show any oil burning so it seemed the only cause could be a loose valve guide. It was. I'm getting the head back tomorrow and both exhaust guides were loose needing oversize replacements. That makes sense now as to the backfiring. Air was leaking into the exhaust ports through the guides.
Why after only 14,000 from total rebuild did the guides get loose? I think due to the pushrods being too long. I'd like not to have the problem again in 5 years, so would like some feedback.
Why after only 14,000 from total rebuild did the guides get loose? I think due to the pushrods being too long. I'd like not to have the problem again in 5 years, so would like some feedback.