Author Topic: Engine Building Questions: CB400F  (Read 1171 times)

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Offline ag12680

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Engine Building Questions: CB400F
« on: November 25, 2014, 07:30:43 pm »
Folks -

It has been over 30 years since I have put this motor together and could use some input from those who do this more frequently…

1. How much torque for the internal M6 bolts holding the primary chain guides, cam chain adjuster, starter reduction gear, etc.?
2. Use loctite (blue or red) or any on the above?
3. Do you lube your shaft seals (crank ends, gear shift shaft) on sealing surfaces and if so with what?
4. Do you dry press the shifter shaft, clutch and kick starter seals or use something to aid their sealing/seating?
5. How wide of a bead for the Threebond/Hondabond sealer for assembling the case halves?
6. Have dry film coated big bore pistons.  How to compress rings without damaging the coating?  Very little chamfer left on the bores.
7. How do you prime/fill the oil pump/galleys before starting?

As I recall, the cylinder base gasket would leak on this motor and I used to spray these these with Permatex Hi Tack which is no longer available (at least in the spray can).   What are the current solutions or leave dry?  This is a 30 year old NOS Honda gasket.

Have a couple of Clymer 400/550 manuals and have searched a bit on the forum.

Excited to see it come together.  It has been a very long time…

Thanks!

Andy --

Offline calj737

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Re: Engine Building Questions: CB400F
« Reply #1 on: November 26, 2014, 05:19:35 am »
M6 bolts only get about 8# maximum. A snug hand tight torque is suitable. Blue or Red LocTite, whichever you prefer, but if suggest Blue as Red is pretty stinking tough to release for a small gauge bolt.

Lube your ring compressor with some oil or assembly lube when installing your slugs after DFL.

Slowly use the kickstarter to prime the oil with no electrical service available. Or, use an automotive type oil priming pump and compressed air. (Kickstart method works just fine since these are dry sump bikes). And, if you've used assembly lube, it shouldn't be an issue anyway.

Just enough bead to not squeeze out, or as some do, spread a very thin bead using a plastic shim so no extra is required.
'74 550 Build http://forums.sohc4.net/index.php?topic=126401.0
'73 500 Build http://forums.sohc4.net/index.php?topic=132935.0

"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis

Offline ag12680

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Re: Engine Building Questions: CB400F
« Reply #2 on: November 29, 2014, 09:36:38 pm »
Thanks!  Much appreciated...