Topic: Advice before I split the cases

[tlbranth]

A couple of questions about sealant. It looks like there was sealant on the mating surfaces astride the main bearings. Is this so? I can't imagine why that would be necessary.
Also, The point seal looks like it might've had sealant applied to the hole it sits in. Is this necessary?

[Jerry Rxman Griffin aka MuthaF'er]

Yes, apply sealer to the saddles by the mains otherwise you will probably get oil leaks. I can't imagine applying sealer around a seal during a rebuild unless there is a specific issue. Sometimes these external seals need replacing without splitting the cases. Perhaps this is why you see it there?? 

[PeWe]

It easy to apply sealer on case surfaces that does not mate. I have done that several times and some of it will later be found on the oil pump strainer.

Around the mating surfaces around case bearings, yes. If not oil leak via the case bolts.

Be careful around the 18x3 o-ring at front side, not too much sealer close to it that can creep inside that o-ring and up in the head with oil flow.

Watch out with additional sealer on gaskets close to the 2 oil holes up to head.

This job is fun, assembly clean parts. Oil is fresh and fresh assembly lube I have used last times.
That feels like a good lubricator until pump will ensure pressure at first start which is the nervous part.

Oil pump priming getting all air out is vital.

Good luck!

[tlbranth]

Thanks for the heads up Pewe. Stuff I hadn't thought of....on account of old age probably.

[754]

The case and bearing bosses are all machined together . So if you did not use sealant there, the case would be pulling down more there than the sides. . Keyword here us sparingly... hope you got a good look or pic, before you removed the old sealant.

[tlbranth]

OK boys, one more dumb question: Hondabond 4 on just one surface or both? The tube doesn't say. I think it's one surface. If it is, any preference?

[754]

One, do the bottom, easier to move around to get the far side..

[Old Scrambler]

+1 on doing only the bottom sealant............have used flat-ended wooden toothpicks in the tight spots. A clean chain does NOT mean its in spec ...........if you loosened the cam-sprocket and about half of the cam-tower to slide the cam out, you can remove the rod-caps and completely remove the crank without disturbing the rings. BE SURE to mark everything before removing to get it back together in the same position. Check with Cycle -X or others about better prices on chains.

[PeWe]

I always clean with acetone before case sealer and loctite where used.
All chains with tensioners to be replaced too, right?

My K2 got BMW timing chains as primary chains.

MessnerMoto has a thread about primary chains on the racing forum. I wrote posts with all details and photos about it after I got the information there.
http://forums.sohc4.net/index.php/topic,154183.msg1799526.html#msg1799526

Both my bikes got new cush rubbers in the primary hubs. I'm convinced that all years have made them hard.
I'll send a hub to Germany for rubber replacement to another engine build.

Check others rebuilds for ideas and not missing anything.

Hondaman has a rebuild thread when he did his old bike.
http://forums.sohc4.net/index.php/topic,122379.msg1386744.html#msg1386744

You might find my K2 engine build informative too.
http://forums.sohc4.net/index.php/topic,168243.msg1948381.html#msg1948381

[tlbranth]

Thanks guys. I'm not replacing any chains or bearings. Sorry to disappoint but gotta draw the line somewhere. If Ofreen can put a billion miles on without ever getting into the engine, I probably can too. I only need another 10 years tops.

[PeWe]

Have you measured the primary chains slack?
Done from under, oil pan gasket surface to primary chain tensioner flat surface.
Service limit is 70mm. New chains ca: 65mm

It rattle some extra when chains have slack.

[tlbranth]

No PeWe I didn't measure it