Smoke, valves and rings
Posted: Sat May 04, 2013 1:24 am
On this glorious day I'm doing post-autumn-rally work on my bike.
1) Charlie thought it was a bit loud in the tappets when I pulled into camp. I just checked the clearances and they were all spot-on. But ahh yes, too much end-float on 3 of the four rocker shafts, I have the later shim adjusted type though and its a PITA to get them spot-on. By the time you take the support blocks off and change shims and retorque it ends up too tight or still too loose. They can wait til I have to get the heads off, and that may be soon-ish ....
2) Its developed a drinking problem. In 2400kms the bike slurped 1250ml of oil! Blue smoke from the exhaust when backing off, I was told. Apart from that it ran OK, it got great fuel economy, pinged a bit under load, haven't checked timing yet but it might be due to carbon build-up. The right plug looks OK but the left one is crusty so I think that's the problem side.
I am off to autobarn now to buy a compression tester to try and assess how much work it might need. Its got second-hand R100S heads and pistons that I just bolted on a year ago. Didn't do much at the time but clean the carbon off and lightly lap the valves. Apart from some small chips in the valve seats everything looked OK, there wasn't excessive play in the guides, not that I spent much time assessing that. I was in a hurry to get back on the road.
I figure if compression is OK then I may just get away with new guides. If compression is low on either side, then the next step (help me here) is a leak down test?
cheers
Mal
1) Charlie thought it was a bit loud in the tappets when I pulled into camp. I just checked the clearances and they were all spot-on. But ahh yes, too much end-float on 3 of the four rocker shafts, I have the later shim adjusted type though and its a PITA to get them spot-on. By the time you take the support blocks off and change shims and retorque it ends up too tight or still too loose. They can wait til I have to get the heads off, and that may be soon-ish ....
2) Its developed a drinking problem. In 2400kms the bike slurped 1250ml of oil! Blue smoke from the exhaust when backing off, I was told. Apart from that it ran OK, it got great fuel economy, pinged a bit under load, haven't checked timing yet but it might be due to carbon build-up. The right plug looks OK but the left one is crusty so I think that's the problem side.
I am off to autobarn now to buy a compression tester to try and assess how much work it might need. Its got second-hand R100S heads and pistons that I just bolted on a year ago. Didn't do much at the time but clean the carbon off and lightly lap the valves. Apart from some small chips in the valve seats everything looked OK, there wasn't excessive play in the guides, not that I spent much time assessing that. I was in a hurry to get back on the road.
I figure if compression is OK then I may just get away with new guides. If compression is low on either side, then the next step (help me here) is a leak down test?
cheers
Mal