Now hat I have a bike with desmo valves I wanted to learn first hand about adjusting them.
I have a friend who had a Ducati shop back in the '80s, and he did the wrenching there. Now he does stuff in his garage and has done hundreds of valve jobs. I sat with him yesterday while he was working on a 900 SS SP. I watched while he did the front cylinder exhaust valve, and while it had been done by someone else 2 years and very few miles ago it was very loose, he thought the closer was at about 4 thou. He did the closer by feel, setting it so that the shim would just turn with oily fingers, then measured the opener and set it to 4 thou.
Although he has more than a full set of shims he could not find a closer that was as close as he wanted it, so after some honing on a stone he eventually stuck it in his lathe and turned it down to the right size, finishing it on the stone.
It was a very interesting and educational time for me, and after seeing how much was needed to be disassembled to get at the valves it gives a little insight into how much the shops charge for this work!
Quote from: SpikeC on April 26, 2014, 01:06:14 PM
Now hat I have a bike with desmo valves I wanted to learn first hand about adjusting them.
I have a friend who had a Ducati shop back in the '80s, and he did the wrenching there. Now he does stuff in his garage and has done hundreds of valve jobs. I sat with him yesterday while he was working on a 900 SS SP. I watched while he did the front cylinder exhaust valve, and while it had been done by someone else 2 years and very few miles ago it was very loose, he thought the closer was at about 4 thou. He did the closer by feel, setting it so that the shim would just turn with oily fingers, then measured the opener and set it to 4 thou.
Although he has more than a full set of shims he could not find a closer that was as close as he wanted it, so after some honing on a stone he eventually stuck it in his lathe and turned it down to the right size, finishing it on the stone.
It was a very interesting and educational time for me, and after seeing how much was needed to be disassembled to get at the valves it gives a little insight into how much the shops charge for this work!
Your friend made it 'perfect'.
Very few shops do the same. ;)
Yeah, I just got done doing my 750 valves for the first time. Took me the whole weekend but got each closer sized perfect and the openers at .004. All the openers were in spec but all the closers were .005 to .006 loose. Motor sounds much crisper and less rattle-ly. Next spring job will be to spiff up the carb. After doing the valves I can see why shop cost is what it is.
As we were dismantling things the belts were a bit loose- we could fit a finger under the belt roller. I have a Gates app on my phone and checked the Hz of the belt- it was 20Hz!