honda cb400t cct

[ChrisC]

anybody out there ever worked on a 1978 honda CB400T.if so how the hell do you remove the rubber cam chain tensioner blade.Ive removed the sprung tensioner but the blade is still attached at the bottom end.Do i have to strip the engine down further? according to the manual the blade should release after you undo the clevis pin on the top...mmm begining to think i should buy a very big hammer


Cheers ChrisC

[Pete.L]

Hi Chris,
I haven't done a 400T but I do seam to remember a couple of bikes I had then the guide was anchored at thier bottom end by the cylinder block. Now I can't quite recall if it was between the block and the gearbox (I think it was ) or the block and the head.
How worn is your guide? does it need to be changed or could you get away with just changing the tensioner.

Pete.l

[ChrisC]

hi pete
Ive had another look today and it appears the guide is attached to the gearbox (as you thought)the guide is worn down by about 20% but considering it s age and mileage it s doing O K (Bit like me really)there is no more adjustment left on the tensioner,so i m considering making my own based loosely on an a.p.e.design.rather than split the engine down further

thanks for your reply
chris

[Pete.L]

the guide is worn down by about 20% but considering it s age and mileage it s doing O K (Bit like me really)

Boy do I know that feeling well.
If you do go down the APE mod take a couple of pictures whilst your at it. I'm sure it'll raise quite a bit of interest on here.
Good luck with that , whichever way you proceed.

Pete.l

[tony.mon]

Right, that problem.
I had a few Honda twins, and they all have a couple of prongs that stick out sideways at the base of the cylinder/crankcase joint.

You can (if you're careful) lift the cylinders on their studs (undo the two or so little 10mm bolts at the side of the cylinders if your model has them first) and just seperate the cylinder base joint by about 10mm or so.

This allows you to turn the tensioner blade through 90 degrees and remove it, without having to refit the pistons into the bores.

Of course, you can't use a new cylinder base gasket, so assuming that the old one hasn't torn or is damaged you can use gasket sealant on the old gasket and reseat the cylinders back down once the new blade's in.

But frankly, unless the blade's worn or there's been other damage causing you to replace it, there's no need to disturb it.

Remember that the grooves in the blade wear grooves inot the blade only until the rollers in the chain start to contact the "land" in the centre of the grooves, and then it's not likely to wear any further. So wear starts off being fairly rapid, but then slows or stops to all intents and purposes once the rollers start bearing on the blade itself.

Phew!
Does any of this make sense?

[Pete.L]

Does any of this make sense?

Oh Dear
I understood all of that perfectly.....I've really got to start drinking earlier in the day

Pete.l

[ChrisC]

Thanks for the reply Tony,I think you explained it very well .Ive decided to leave the blade in place as it,s not to bad,but i will keep it in mind,or better still write your info into the bikes manual .Because there is no more adjustment left i have started to make my own manual tensioner and as surgested by Pete L, I have taken a couple of pictures if anyone is interested......if it works.. ...if it dos, nt i will take a photo of the remains too! Either way thanks again.
just a note for Pete L try soaking you rice crispies in Glen Livet and you,ll understand everthing about everthing all day...hic !!

Cheers ChrisC

[Pete.L]

just a note for Pete L try soaking you rice crispies in Glen Livet and you,ll understand everthing about everthing all day...hic !!

Wow! That's gotta be the way to do it

Pete.l

[tony.mon]

Thinking about it, I've never seen a Honda tensioner blade worn down to the backing steel, and I've certainly abused a fair few!