XR100 Ticking

kb228
Profile picture for user kb228
Posts
6153
Joined
1/31/2018
Location
Mansfield, OH, USA
kb228
Edited Date/Time 4/29/2020 4:41pm
Just got an 02 xr100 to use as a pit bike. We rode it for 5 hours and the top end was smoked. Put a new piston and rings in and reassembled. The top end is ticking loudly as if there was excessive valve clearance. This didnt happen before teardown. Bike has 0% on the leakdown test and 150psi+ compression.

I ordered a new timing chain in hopes that will fix it. But because it didnt tick before teardown i have my doubts. Turning the upper timing chain adjuster did not change the ticking sound.

Anyone familiar with these bikes have any advice?
|
kb228
Profile picture for user kb228
Posts
6153
Joined
1/31/2018
Location
Mansfield, OH, USA
kb228 4/25/2020 8:18pm
4/25/2020 8:18pm
Bumping this post. New timing chain didnt fix it. Tore back down to verify assembly and no issues. Cylinder bore is within spec. No play in crank. Beyond stumped here. Only thing i can hear with the stethoscope is a ting around the exhaust valve - but no issues as far as function that i can see. No piston/valve contact and the valve is moving freely
RH101
Profile picture for user RH101
Posts
8
Joined
4/29/2020
Location
AU
RH101 4/29/2020 1:16am
4/29/2020 1:16am
did you follow the procedure in the service manual? the timing chain has a lower adjuster on the back of the barrel which is used for gross tension adjustments and the upper adjuster will only do minor adjustments.
Sachmo831
Profile picture for user Sachmo831
Posts
252
Joined
10/7/2015
Location
South Bend, IN, USA
Sachmo831 4/29/2020 11:33am
4/29/2020 11:33am
Did you check the condition of the cam journals? Lack of lubrication can wear them down quickly. Picture shows an xr80 head that the cam chain wouldn't tighten up and kept making noise. The cam was wearing through the head sinking down to where the cam chain was too long

kb228
Profile picture for user kb228
Posts
6153
Joined
1/31/2018
Location
Mansfield, OH, USA
kb228 4/29/2020 4:41pm
4/29/2020 4:41pm
Yeah looked at all of that. I found the problem. What happened was i installed the cam upside down and adjusted the valves to the upside down cam’s clearance and it actually caused really excessive valve clearance. All good now.

Post a reply to: XR100 Ticking