R27 250cc Cylinder bore hone carbide? preparation? BoreTech

[Curt]

(R27 250cc Cylinder bore hone carbide? preparation ? BoreTech)

Any down side to the optional carbide treatment?

Cylinder has two pressed in chrome pushrod tubes and an oil supply tube. Do these need removed for bore/hone/carbide?

Grooves in bore make me think prior owner's spark plug may have failed. Does machine shop ever offset the boring axis slightly to clean the deepest groove with least bore oversize?

[Duane Ausherman]

I have only bored a few cylinders myself. I don't know about the offset idea, but I think it risky. What does a spark plug failure have to do with the bore?

We never removed the tubes for boring.

[Kurt in S.A.]

I had the bore of my R25/2 treated by BoreTech. I sent everything to Vech and he took care of the rest. I didn't remove the chrome tubes...Richard Sheckler said they need heat to remove, so I left them alone and let Vech do his magic.

I'm about 150 miles into break-in. Bike's running fine...I am getting some smoke on decel...Richard at Benchmark said that is to be expected until I can get the rings to seat.

Kurt in S.A.

[Curt]

Once on an air-cooled VW, I think, I pulled a plug with part of porcelain (from around center electrode) missing. Seems such would be hard and sharp and could groove a cylinder wall.

[Major Softie]

Don't know if porcelain could, but an electrode certainly could.