Topic: Help With Bottom half of engine

[theslayedsaint]

Hey guys,
 So I've got a question or really just some advice/Tips. i'm about to put the bottom half of my cb750 back together!! can't wait for this thing to be done! however this is my first build and i'm a little nerves that i'm going to make some stupid little mistake thats going to cost me big. so i thought why not post pictures and ask all you CB guys for some help. any thoughts on things i may have forgotten or thing you can see i'm missing would mean a lot. I've taken the chain oiler off so yes i do know thats not there and i need to add the rods also.

[Davez134]

You probably have them in the top half of the case, but make sure you have the 3 dowels in the case, with new o-ring around front. Also, not sure if you plan on putting top case over bottom just like that, or if its just for pictures, but you should put crank, primary/cam chain, trans in top case then lower bottom case onto it. Those c-shape clips for trans bearings must be seated in their grooves in top case half. Disregard if you already planned on this.

[theslayedsaint]

Thanks!
I was trying to figure how to do that without everything falling out. I'll give it a try now thanks.

[Davez134]

Top case should look like this, just missing dowels in this pic. I put a towel under to raise up so rods could hang down freely...


Bottom case should be like this with addition of kick start, primary tensioner. Make sure shift drum is in neutral position.



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[theslayedsaint]

Did you put the studs in after you closed the case?

[Davez134]

Yes

[flybox1]

triple clean your case mating surfaces with acetone and a rag/q-tip before you apply your sealant and put them together.
new seals at the end of your crank and next to your drive sprocket. 
new oring at the oil galley (leading edge of your case halves)


 

[iron_worker]

The crank seal on the points side is another good one to remember ... it's shouldered and can only go in with the cases split ...ask me how I know... 

IW

[PeWe]

Only sealant where the cases have contact with each other
I have done too much back in the days with sealant drops later on clogging the oil pump metal filter. No problem since I cleaned the filter (mesh) but I'm not sure if it can reach the oil channels in the top end.

One more thing: Do not use Hylomar blue as sealant between the cases. It WILL leak! I got that information from a friend back in the days that had done several engines . I did not follow the advice and the cases were leaking. Not much but always dirty engine. Hermetite Golden did work very well back in the days, now not available anymore.

I used Hondabond on case halves last time (2013) which seems to be very good. Too good as sealant on paper/fiber gasket when its like a glue. I had to scratch the head cover + head clean for an hour or 2 when open it. New gasket with Permatex copper spray that make it possible to open head cover again and again with same fiber gasket,

Permatex Copper spray gasket work well on fiber gaskets as extra sealant. I used as extra ensurance on cometic fiber head gasket.