B4 Won't run - Timing?

[bullet5]

Hello all, first a quick introduction. I've been a banditeer for a few years now, and have been a member of the "BanditForum" for a number of years aswell. I started off with a 1999 Mk1 B6 which I brought back from a sorry state, and I've just bought a 1993 B4 VC (jap import) for the pricely sum of £350 with a spare engine.

The catch?

Well of course there is one at that price, and it's that neither engine works.

The original one has terrible scores and pitting on the cylinder bores, and instead of repairing it, the previous owner bought another VC engine from a "running" crashed bike. This is currently installed in the bike, however again it doesn't run.

The Problem:
When the engine is turning over, fuel vapour is being emitted from the air inlet side of the carbs (air box is off at the moment). My guess is that the timing is out, but can anyone verify this?

Any tips/advice most appreciated.
Thanks again,
Bullet5.

[bullet5]

After many an hour searching the net I managed to find a few service manuals for some versions of the B4. With them I managed to piece together some information on where to being the strip down. 

After removing most of the plumbing and electric work from around the engine, I managed to take the rocker cover off with the engine in place. It's a tight fit but it comes out after some effort. 

Going on what the manual was showing for the '97 B4 VC, my exhaust cam was 1/4 turn out and the inlet was 1/2 a turn out. It looks as though someone has already been in as there is the odd gasket missing here and there. 

It would appear that the cam chain tensioner (automatic, spring loaded system on these) has been tampered with at some point in the past as it's broken. I suppose this could've been the cause of the problem, as if there is no tension the chain could've jumped the cam sprockets and hence altered the timing

Anywhoo, after much faffing about the engine is back together with the exception of the cam chain tensioner. I've had it apart and tried to fix it, but there appears to be something wrong with the sealed mechanism, and as I can't get in there it looks like I'm on the hunt for another one, before I can try turning the engine over.

I'll keep you posted on the outcome, hopefully this is it solved, and the valves/piston heads haven't been damaged.

Thanks again,
Bullet5.

[bullet5]

Right, I managed to strip down the automatic tensioner and fix it. It's now working beautifully.
The cam timing is set up as in the manual, however I'm having doubts.

Should I be taking the timing out of the '97 VC manual or the 92-93 "normal engine" manual?

The cam shafts should be in roughly the same position, however there is a 4 link difference between the tops of the sprokets

Any idea which manual I should follow? 20 pins for the normal and 24 for the '97 VC. Is there a difference between the different years of the VC engines?

Much appreciated,
Bullet5.

[bullet5]

Please please do, i've been going mad trying to figure it out.

They're both 1st generation engines (K707) and both have the variable valve system on the inlet & outlets, so I can't rely on the '97 manual as this is for the 2nd gen, with only variable timing on the intakes. (Oh and yes she's a japanese import)

21 pins sounds better than 20, and would make the cams sit a little more "square" in position, and what I mean by that is that the numbers/marks on the cams would both sit (from what I remember) vertically/horizontally a little better. I.e at the moment they are a little off, but I put that down to wear/stretch in the cam chain.

Thanks again, and I could really do with your opinion on this.

[Chris H]

First gen V's, VM for example are 21 pins, cam sprocket markings are all the same.
Remember when setting the valve clearences up up need to do 3 separate clearences.
1) low this is the large shim.
2) smaller top hat shim.
3) clearence between high and low using the nut and pin.
Good luck LOL.

[bullet5]

Thankyou! Looks like it is 21 afterall

I'll have another go and take some pictures, as the internet needs a guide for this thing. It's been a nightmare finding out all the information I've needed.

Next thing i've got to find out is the valve clearances for all 3. Hopefully this will be solved with a little bit of searching.
Saying that, the diagram would still be greatly appreciated Speed

Thankyou again everyone!
Bullet5.

[Chris H]

I have the VM manual in PDF, pm me ya email and i will sort it out for you.
Ive had a VM for over 15 years and rebuilt a couple of motors and when i say the valve clearences are a pain in the ass i mean it 100%.

[bullet5]

Thankyou, that would be most appreciated! 
And from what I can see they certainly are. I didn't enjoy doing my B6 a few months back, but this is rather... scary.

PM Sent.

[stormi]

Chris,

Can you email me the manual and i will post it here?  It would be very useful for a number of members I think...

[Chris H]

stormi,
No problem, they are loose pictures that really need stitching into a book.
I zipped them up but the file is too large to mail so i will have to send them in parts, is this ok?

Chris.

[stormi]

Sure,... the other thing I can do is give you FTP access, then you don't have to mail them?

[bullet5]

Sorry for the delay in responding, I've been a tad busy.
Thankyou greatly for the picture! I shall make sure I use 21 pins in future

Got a problem currently, as I've found that one of the links on the cam chain has been stretched to 1.5 times it's original length, so I've got to replace the cam chain

Has anyone had to do this before, who can lend some tips?

I've seen continous chains for sale, but this would require (from what I can gather) stripping the engine down to nothing and a complete rebuild.

There are a few places that say they supply split link chains awell. This seems a heck of a lot easier, as I can cut this chain, then thread the new one around with the old one, without having to strip the engine.

Has anyone had any experience with split link chains for cam purposes? (Rivet links)

Thanks again
Bullet5.

[bullet5]

Sorry for the delay, I kept checking my email but some how managed to repeatidly overlook your messages

Thankyou greatly for the time and effort to send them 
I assure you i'll make sure I give them a good read though and print/store them somewhere safe.

I'm still waiting for a reply from the chain supplier as to wether they can supply an open ended chain for my model.