LowpsiTSi Posted April 2, 2010 I own an '87 xr250 that has had a ticking issue since it was bought. The bike still ran good but I always knew it needed looked at. Once the ticking became more prominent we decided to pull the valve cover and found this : We found worn and scored rockers and camshaft. They were both replaced. The issue now is that there is zero gap between the valve and rocker on one of the exhaust valves. This led me to believe that I had a worn valve seat or valve. But after some thought I remembered that the rockers have been adjusted before without any trouble. And if there really was no gap between the rocker and valve I would have had to fight the cover to bolt to the head. But the cover sat on to the head without any trouble. Has anybody ever ran into an issue like this rebuilding the top end? Share this post Link to post Share on other sites
Trailryder42 Posted April 2, 2010 I think I see where you're going with your logic. But looking at the wear in that rocker face, if the valve/seat is worn by the same amount, it's proportional wear, so you wouldn't have head seating issues. Or, do you mean to say, with the new parts, you'd have thought you'd have had trouble with the head seating? I would try to figure out what thing was so out of whack that it made one thing cause wear like that in the other. What rocker was this, exhaust, left or right? Share this post Link to post Share on other sites
ATJ_Number_1 Posted April 2, 2010 Have you tried adjusting the valves since you put it back together? Seems like you would have but you didn't really say. That rocker looks like someone ran a hardwelded cam with stock rockers. Share this post Link to post Share on other sites
creeky Posted April 3, 2010 If it is the RH exhaust rocker that has no clearance, it has been misadjusted due to the cam mounted auto decompressor being activated during adjustment. Share this post Link to post Share on other sites
mcnutty Posted April 3, 2010 The '87 XR250 didn't have a cam mounted auto decompressor. If it is the RH exhaust rocker that has no clearance, it has been misadjusted due to the cam mounted auto decompressor being activated during adjustment. Share this post Link to post Share on other sites
creeky Posted April 4, 2010 The '87 XR250 didn't have a cam mounted auto decompressor. You are correct! Not paying attention. 👍 Share this post Link to post Share on other sites
Perc82 My Rides (2) Posted April 4, 2010 (edited) You are correct! Not paying attention.🤣 No auto decomp in this pic?👍 http://webservices.motorsportdealers.com/parts/partImages/HOM/2/14KK1E/ILLUST/KK14E/0300.Gif What year did they start using a auto decomp? Perc Edited April 4, 2010 by Perc82 Share this post Link to post Share on other sites
creeky Posted April 4, 2010 What year did they start using a auto decomp? Perc '96 models. Share this post Link to post Share on other sites
