Cyclinder rebore services in greater London?

[Athame57]

The workshop just got back to me to tell me I will need a rebore or a different cyclinder block, unless someone here has a CB400F2 cyclinder block for sale the only one I can on the web find is aweful.
Can anyone reccommend a place to get that done in Greater London. The quote I got from the one firm discovered so far is £140.00 plus vat for a first rebore.
However, how can I be sure it is a first rebore, is there a way of telling from pistons or something?

[Nurse Julie]

You won't know what + size over rebore is needed until a rebore is done. That's why you never order piston and ring kits until you know which size you need. Don't bother going +0.25 over, its not worth it, if it doesn't clean up at +0.50 then you'll need to go bigger. Has the garage actually taken the top end apart to see what has happened or is this guess work?

[Bryanj]

Yes, but its easier to measure the bore, i can rebore it for you if you wish and import pistons from Japan, quick guess is £140 for 4 piston kits(piston, rings,pins, circlips) plus rebore and postage.
You have to be carefull with these as piston to bore clearance is very tight and most car engine builders get it wrong.
Piston kits from cruzinimage are available in 0.5 and 1.0mm oversizes.
You can email me direct addy is in my profile

[Bryanj]

There are 2 blocks on fleabay, 1 at 58 plus 6 postage the other over 100.
Both look like they need boring, which can be done, get in contact and let me know

[Athame57]

Has the garage actually taken the top end apart to see what has happened or is this guess work?

I'll be going there tomorrow morning Julie, it's heaving down with rain here now so not today!

[exvalvesetdabbler]

However, how can I be sure it is a first rebore, is there a way of telling from pistons or something?

If the rings are over size it should be  stamped on the top face of the ring.

I have a good cylinder block in the shed but the liners are scrap. They're already +50 with a deep gouge on one where a washer was embedded in the top and side of the piston. I only kept them because the fins were undamaged.

Regards
Dave

Regards
Dave

[Bryanj]

Trouble is that the markings on the rings are so light they wear off and cant be seen, similarly pistons used to stamped on the top but recently seen quite a few just written on in marker.

Only certain way is measuring, vernier calipers shoul be accurate to 0.25 mm, actually a steel rule should be that accurate!

Its now difficult to find both 0.25 and 0.75 mm oversize parts, Cruzin only do 0.5 and 1.00mm, having said that i have done quite a few 500 blocks in the last year and only one cleaned at 0.25, all the others were found to be "barrelled" in the bore

[TrickyMicky]

This is just a "pie in the sky" thought, But if you should ever win the lottery or similar, DSS has genuine standard size pistons and rings in stock, and Megazip in Japan have a new genuine cyliner block in stock. I can't put the price on here as there is not enough room!!!!!

[Athame57]

I can't put the price on here as there is not enough room!!!!!

How about 'all the tea in China'?

[K2-K6]

If the bore can't be reliably refinished at smaller oversize, then going straight to 1.0mm would be a sensible route to recover the liners in situ .... unless its fundamentally not going to be serviceable at all. The mechanic suggestion of rebore indicates its not catastrophic though.

More importantly, why did it fail is crucial to know. If that's not clear, then the same risk is present for the new component etc.

Can you get pictures of the damage in bores, pistons (skirts and crown etc) to post and draw observations on here ?

[Athame57]

Can you get pictures of the damage in bores, pistons (skirts and crown etc) to post and draw observations on here ?

Well, it's all wrapped up now! But yes, I need a rebore on some barrels. I was going to do this about a year ago when I had the bottom end rebuild and camchain system rebuilt but couldn't afford to anymore.
Mechanich is satisfied a rebore and new pistons will cure the bike, he knows her well by now btw!
I'm just going to get a hold of BryanJ.