Topic: 75 CB400F Splitting Cases loose but not apart

[r6100mph]

yeah that's a good call on the cam chain, i'll replace it along with all the oil seals, new inner and outter springs for the bar (plunger) and obviously a new gasket set. 

Any ideas on places to order these parts?  I would like to find one place to order from, just to keep things simple.

I'll grind down the crankcase where the cam chain has eaten into it.

the cam chain arm (u-shape piece) i wont replace because it does pivot freely. 

Is there a way to tell if the slipper needs replacing?  should there be come flex in it, so when there is pressure put on it, it bends tensioning the cam chain?

Thanks a lot for all the feedback and suggestions!  it really does add another level of confidence when doing things for the first time!  I appreciate it!

[bryanj]

www.davidsilverspares.co.uk for everything.

Post some pictures of the slipper showing the ends where the rubber bonds and the middle, Make sure the "caps" are in the top holder and slipper.

I seem to remember that a couple of the head nuts have coppered washers and sometimes these will leak if not replaced

[r6100mph]

i'm in the process of painting cases, and using the PJ1 Yamaha metallic silver engine case paint, and it looks great!

I have a question on the cylinder head studs.  I have one that doesn't seem to be all the way down into the lower crankcase.  Should I be concerned? 

It wont come out and it wont go any further in.  Does anyone see a problem with it when i go to re-assemble?

[r6100mph]

Here are a couple pics of the cleaned up cases.  I'll post some pics of the painted parts soon.

[bryanj]

Should be no problem with stud but there will be with leaks if you dont remove all those bits of gasket

[r6100mph]

thanks,  all of the gasket has since been removed.  I used Permatex Gasket remover, and a sharp razor blade.  But watch out for this stuff, talk about corrosive, i was using rubber surgical gloves, and my fingers started to burn. 

Worked great, but definitely needs to be thoroughly cleaned once all the gasket is removed. 

[r6100mph]

some pics of the painted engine.  Still waiting for some parts from Honda parts direct, before i start assembly.  Will do the valve cover, etc while i wait for cam chain and some other parts.

For paint i used "PJ1 Yamaha Metallic Silver Engine Paint".  Directions say apply directly to parts, no primer.  Seems to go on pretty good and dries quickly, put 3 coats on each piece.  Then let is really set up for a week or so, before handling. 

Degreased all the seperate parts multiple times, then powerwashed, and wiped down w/ acetone before paint and masking. 

I'm definitely happy with the results!

[r6100mph]

After painting the engine, it's time to start assembly.

Question regarding the gear selector:
Does it matter how the gear selector is rotated?  If all the forks are in their correct locations, left, center and right along the notches in the gear selector, everything should be good correct?

Rotating the gears by hand, and selecting gears by rotating the gear selector by hand, everything seems to be smooth, but I cant seem to find neutral.  When in neutral, the sprocket shaft should NOT spin correct?








Another question regarding the oil seal on the main shaft on the clutch side, i got an entire set of new oil seals but this new seal doesnt have the rigid metal plate in it, just really flimsy rubber.  Should i try and locate an OEM oil seal, or will this Sudco seal work just fine?  Anyone have experience with these?

Original seal on left, new replacement seal on right:


Pretty Flimsy:



Thanks to everyone for helping me out with this first rebuild!  Hopefully this will help others in their hesitancy for tackling a rebuild.

[r6100mph]

Got the neutral issue figured out after I installed all the shifting mechanisms, and the neutral arm.  Pretty easy to notice the neutral arm goes into the notch in the selector drum.  Goes through all the gears smoothly and deliberatly.  Finds neutral no problem.

I'm going to order an OEM oil seal to replace the flimsy Sudco oil seal.  That's the last thing i want to happen when i get the engine back together and have an oil leak out of that seal.

Starting to put the Primary shaft and bearings into the upper case.  Notice that one bearing wasn't turning so smoothly, tried to clean it out with brake cleaner, then re-oiled it, and still there a noticeble roughness to it.  So i'm going to replace both primary shaft bearings.

I found a local bearing shop US bearings, as long as the universal bearing number is correct, it shouldn't matter what brand it is right?  Obviously im going with a regular open bearing like the existing ones.  Anyone ever had to replace engine bearings with another brand/ type?