I've re-posted this because my original post is now buried behind twenty pages of utter crap, if anyone, apart from me is still reading on this list they may be interested in what follows.
Those of us who's CB72s or 77s are plagued with oil leakage near the spark plugs might be interested in my recent 'experiment' to fix with this annoying issue.
Having owned CB77s for longer than I really care to remember I've known about this issue for years. Some engines seem to leak a bit of oil in this area, most don't. Some leak a lot!
American Honda published a Service Bulletin about it back in April 1966 so obviously the problem was recognised even when the bikes were new.
Since retiring a few years ago I've built myself both a CL77 and later a CB77 to go with it.
Both engines were rebuilt with new cylinder liners and in both cases the machinist, as was his usual practice, machined the top of the new liners dead level with the top of the cylinder block.
At this point I must state that this guy has been working on Honda engines for over fifty years and I would always accept his opinions and advice and experience as being vastly superior to my own.
However, sadly, both of my newly built engines had minor oil leaks around spark plugs, not much but something I found intensely annoying as Hondas, even back in the 1960s, weren't supposed to leak oil!
Reading the Honda Bulletin on this subject I was inclined to blame the fitting of the cylinder liners but wasn't really convinced that an engine rebuild to adjust the fit of the liners would affect a cure so I procrastinated and did nothing other than clean the engines regularly.
Earlier this year I spotted a reference on this list to a 'repair kit' offered by Arie Boers and after some thought decided to give them a try.
Deciding factors were that the kits were simple to fit and could be installed without any dismantling of the engine, in addition the kits cost no more than a gasket set which I would have needed anyway if I had embarked on an engine rebuild, the results of which were by no means certain.
I've now fitted the kits to both engines and really pleased with the outcomes; after 1500 miles (CL77) and 600 miles (CB77) both engines are completely clean and dry in the area surrounding the spark plug so have entirely vindicated by decision.
Based on my own experiences I can recommend these kits to anyone with a similar problem, the only caution I would add is that TOTAL cleaning of the area around the before fitting the kits is essential, as in most things, proper preparation is key to a successful job!
I have no connection with Arie Boers other than as a (very) satisfied customer.
Oil leaks near the spark plugs.Cyl Head leakageYou can contact Arie on aboers@comcast.net
I've never mastered posting pictures to the site, I'll E-mail details and pictures to you direct and to anyone else who wants them if you PM your E-mail address to me. glad to se I'm not the only one still on the site! DJM Re: Cyl Head leakageI'm still here, but progress is slow on projects at the moment as I sort out the mess of 20 years of stockpiling projects to work on!
There is always something to do that is more interesting than what you intended to do... :-) I'm getting there..... G
'60 C77 '60 C72 '62 C72 Dream '63 CL72
'61 CB72 '64 CB77 '65 CB160 '66 Matchless 350 '67 CL77 '67 S90 '77 CB400F
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