CB400F Engine rebuild

[taysidedragon]

Hermatite Bryan, or Instant Gasket as it was named then.

Worst basket nut I've ever seen.

If you need some new points screws I've just got some, come with captive flat and spring washers. £2 for the 6 needed inc P&P.

Thanks for the points screws offer. I'll let you know if I need them. 👍

I'm going to split the cases tomorrow,  so far not a single stripped thread!

I hope I haven't put the fluence on it now. 😕

[Bryanj]

Thats my damn dyslexic fone again Ken i meant Hermetite.
Julie the green stuff, if it was hard and flaked off was probably Green Hermetite, fairly common on the old Brits along with Red

[Bryanj]

Ken you are mixing eras there

[taysidedragon]

This engine has had a chequered past! It's been opened at least twice before. There is red Hermetite in a lot of places, then some black engine paint remnants on top of the Hermetite. Some of the engine paint even got inside the cases. 😯
The Orange silicone sealant was used the last time the engine came apart, it's horrible.

The primary chain guides had washers underneath them between the guide and the case. These aren't shown on the parts diagram so I assume they shouldn't be there.
Was this an attempt to 'raise' the guides and take up some slack in the worn primary chain? The guide fixing bolts were mostly non standard.

[taysidedragon]

Just out of interest, the manual says to replace camchain if 6mm longer than standard, but I can't find the standard length published anywhere.

I'm not going to use the old camchain but curious about how worn it was.

[Nurse Julie]

Just out of interest, the manual says to replace camchain if 6mm longer than standard, but I can't find the standard length published anywhere.

I'm not going to use the old camchain but curious about how worn it was.

Lift the chain off of the cam sprocket and if you can see a gap between the top of the sprocket and the underside of the chain, it's well beyond spec. But to answer your question, I have no idea where it says in the shop Manual or Haynes just how long it should be 🤔🤔🤔

[taysidedragon]

I did that before dismantling and there was some play, but I didn't pay much attention to that because there was no tensioner clamp bolt and the horseshoe was stuck.

[taysidedragon]

I had a happy ending over the weekend, no, not that kind of 'happy ending!' 😁

I was preparing the cylinder head for painting and had to remove the rock hard carb rubbers from the inlet stubs. The screws would not budge. JIS screwdriver bits, releasing oil, impact driver, heat. None of them would budge the screws so I had to drill the screw heads to remove the rubbers. That left the threaded stubs sticking out of the inlets. I thought they would be a challenge to remove, but they came straight out, threads clean as a whistle!
The screw heads must have been 'welded' to the rubbers and that was the only thing stopping them coming out. I was very relieved. 👍

[mattsz]

Bullet dodged! 

[taysidedragon]

After dismantling and inspecting my spare engine I found that it needs nearly everything replaced. New pistons, rings, rebore, conrods, shells, primary and cam chains and at least one gear so it's been put back on the shelf.
I took my fitted engine out and dismantled it to find it is in better condition overall and just needs new rings, primary and cam chains. New parts to be ordered and engine re-assembled. 
I wish I'd started with the fitted engine first, but it was easier to start work on the engine that was already out and on the workbench.

One thing I found on both engines was the pistons had been numbered backwards with numbers scratched inside the piston skirts. Now I know that as long as the components were put back in the same cylinder they came from it doesn't really matter, but it worries me that they might not have been put back right. What else was done wrong? Is this something that is often found when opening these engines? It really bothers my OCD! 

[taysidedragon]

I forgot to mention the camchain tensioner.  The horseshoe was stuck and the loose camchain was grinding on it quite badly. Luckily I have a good one to replace it with. 👍

[K2-K6]

"I had a happy ending over the weekend, no, not that kind of 'happy ending!' 😁"
 

Helping a friend with making a patio once,  his diy instructions called for "4 yards of well rammed aggregated hard-core" to which I thought,  that's certain to make someone's eyes water! 

[taysidedragon]

"I had a happy ending over the weekend, no, not that kind of 'happy ending!' 😁"
 

Helping a friend with making a patio once,  his diy instructions called for "4 yards of well rammed aggregated hard-core" to which I thought,  that's certain to make someone's eyes water! 

Ouch! 🤕🤕🤕

[taysidedragon]

There is quite a lot of play on my Countershaft bottom gear and a small amount on Mainshaft top gear.

Is this normal or do they need replacing/rebushing?

[taysidedragon]

There is quite a lot of play on my Countershaft bottom gear and a small amount on Mainshaft top gear.

Is this normal or do they need replacing/rebushing?

Can anybody give me some advice on this? New gears are available from CMSNL but over £200 each! Any idea how much it's likely to cost to get the bottom gear rebushed?