Removing surface rust from cylinders

[rockcitycafe]

where are you getting the .25 piston and ring sets? anytime I ever check, the 836 sets were less than the first over ones. also, I agree with Tim, that pitting looks pretty deep, mind you .25mm is only .010", and that turns into a cut depth of .005", which is the same thickness as a sheet of copy paper. Also, whatever pistons you go with 836 or 1st over, definitely bring them to him to measure and match, if he doesn't say he needs them, don't use him, no matter what the price

 

[bigring]

Good point Tim. This is all new to me - glad you guys are helping me out. Going over to have the guy look at the cylinders tomorrow night. Will keep you posted.

 

[bigring]

Okay, took it over to the guy tonight. He says that the pitting is fairly deep. He said he could bore it out but the pits would still be there, small pin holes. The pitting is just in #4, the rest are fine. He suggested that I just run it with new rings and see what happens - if it leaks then pull the cylinder block and get a new one or fix it. He offered to de-glaze it and the others to smooth things out. I suggested that even with new rings the pitting would still allow seepage. He's a bit of an old-timer and seems that worrying about a 30 + yr old bike with one cylinder in not the best condition is not the end of the world and to just run it.

Seems to me, based on what RCC said about upgrading to an 836, and taking off 4mm the cylinder walls would take that pitting out, wouldn't it?

What do you think?

Pros for not doing it - I'd save cash and time.
Cons - might end up with a shitty running engine and leakage.

On a good note, he checked the gasket surface on both sides and it's flat as a pancake - just needs a little fine tuning.

 

[rockcitycafe]

No way, those pits will destroy your rings. Go with an 836, it's going to need .080" removed from the surface, it'll definitely get down past those pits


Sent from my iPhone using Tapatalk

 

[bigring]

It didn't make sense to me that he said that. I think I'll go that route RCC - even if the pitting is still there with 0.08" removed the pits will be way smaller if not gone altogether.
Will be sourcing another machine shop this week. Cheers RCC!