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I guess it depends on what might be wrong. I've just spent £450.oo on parts and £700 for labour, price agreed beforehand, presently my bike is still in the garage. I was advised to get the rebuild because of leaking gaskets and some seals. I opted to get the cam chain, it's 'horseshoe' and tensioner blades complete changed while things are open and a broken piston ring was also found. Nothing else that really matters has come up. Mine is a 1978 CB400F with 40,000 on the clock, the last 12,000 were gentle ones with me.
How were the bores?
Have you priced a rebore recently, the last four sets of 500 i did did not clean at 0.25 as the bores were "barelled" had to go to 0.5
Quote from: Bryanj on February 25, 2024, 05:34:45 PMHave you priced a rebore recently, the last four sets of 500 i did did not clean at 0.25 as the bores were "barelled" had to go to 0.5I've not had to rebore anything yet. Im guessing its going to be atleast a couple hundred pounds. I'm going to contact an engine machine specialist near me tomorrow.
I agree with all the above and would add a caveat to the rebore work and that is be very wary of the man down the road who is used to reboring car or British motorcycle engines. Japanese motorcycle engines run very tight tolerances. The individual pistons should be measured and numbered. The bores are machined to suit the individual pistons.I second Ted & Bryanj's recommendation, get the rebore done by someone who knows what they are doing with regards to these engines. The specific tolerances are in the Haynes manual.I had a Honda CB250RS rebored by a so-called specialist five years ago. Despite giving him the tolerances he decided to do it his way as he thought the tolerance was too tight and the piston would sieze. Guess what, this is exactly what happened but not because it was too tight but because the 'specialist' bored it out as he would a British bike and didn't tell me. The engine used a litre of oil in the space of 50 miles, the bike sump only holds 1.5 litres, result a full seizure on the M40 motorway on a newly rebuilt motor. There was a big hole in the top of the piston on inspection.Only use people who are recommended by others on this forum to save yourself a lot of pain and money👍