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British Bikes / Re: TR25W- Exhaust valve problem?
« on: March 27, 2011, 07:31:55 PM »
Hello,
Sorry for the slow response, been at relatives this weekend.
Thank you for your responses R and Goldy. I've not had a chance to examine things again but I do have some questions! Don't read them as an attack on your suggestions, just me trying to understand the problem better.
The valves were replaced about a year ago and have had less than 250 miles use. Does this make it any less likely that the valve has stuck, this combined with the fact it would have stuck after 30 miles of riding. I might not understand the mechanisms with which a valve would stick properly, but surely it would be at the start of a journey? Is it just a build up of dirt which would cause sticking or is it a tight valve expanding and sticking inside the guide?
I'm also quite surprised at the small amount of movement in the cam follower, I actually noted this before replacing the push rod (watched it using a mirror, the inlet rod appeared to move a lot compared to this one). I thought perhaps the exhaust cam follower had dropped which allowed the rod to fall out of place (indication of a failed cam shaft/cam follower?).
With regards to your question, there was a very large valve clearance (>>0.25 inches) when I started to look at the problem. I adjusted this back to spec but the push rod movement is so small it isn't really shifting the valve at all.
I'm not going to get a proper look at the engine until next weekend but look forward to any suggestions you have.
Thanks again for your help.
cpp01
Sorry for the slow response, been at relatives this weekend.
Thank you for your responses R and Goldy. I've not had a chance to examine things again but I do have some questions! Don't read them as an attack on your suggestions, just me trying to understand the problem better.
The valves were replaced about a year ago and have had less than 250 miles use. Does this make it any less likely that the valve has stuck, this combined with the fact it would have stuck after 30 miles of riding. I might not understand the mechanisms with which a valve would stick properly, but surely it would be at the start of a journey? Is it just a build up of dirt which would cause sticking or is it a tight valve expanding and sticking inside the guide?
I'm also quite surprised at the small amount of movement in the cam follower, I actually noted this before replacing the push rod (watched it using a mirror, the inlet rod appeared to move a lot compared to this one). I thought perhaps the exhaust cam follower had dropped which allowed the rod to fall out of place (indication of a failed cam shaft/cam follower?).
With regards to your question, there was a very large valve clearance (>>0.25 inches) when I started to look at the problem. I adjusted this back to spec but the push rod movement is so small it isn't really shifting the valve at all.
I'm not going to get a proper look at the engine until next weekend but look forward to any suggestions you have.
Thanks again for your help.
cpp01