Thanks for the replies and advice. I asked Blane Engineering to bore to 0.004" clearance as indicated by JP. Apparently this is too tight. Yesterday I asked Blane to hone out to 0.006" and Mike has phoned this morning that this has been completed. Hopefully this will do the trick.

Charlie

The JP piston, you can obviously see it has been nipping up. There are only very light marks on the bore and rings. Should I get the bore honed? And stone the piston a bit? Ring gap is 12thou.

Charlie

PS I note the advice from Paul and Nev.

Les and Nev, I am using Silkolene Chatsworth 40.

Thanks, Klaus, that is equivalent to 0.0047"

Hi, all. I have run 900 miles on a JP piston in my 38 VH engine and it still wants to nip up. I asked the engineer to bore to JP's recommendation which is 0.004", however apparently this group recommends 0.006" clearance. I will dismantle the machine shortly. If I have the bore honed, will...

Call me ignorant but I rode my 55 NH for 30 years with no spacer before I realised it needed one. I just cut steel tube to length.

Charlie

Hi, all.
When doing the pleasant job of mounting the magneto to a single, should I use spring washers on the screws?

I have used the proper size of string from ebay and also PTFE tape and there is still a small weep.

Hi all!

Has anyone ever used o rings under the seal holder to keep the oil in?

C

Thanks all.