Cam chain adjuster bolt 400-4

[Tiny Tim]

Right next stupid question.
At some point in its life my 400 has had the cam chain adjuster bolt located at the front of the engine replaced with a none standard part. I now have the right bolt, washer, o ring & nut to replace the crap one.
What I can't figure out is, can I just remove the offending item and fit the new one or is it more involved.

Cheers

Tim

[mike the bike]

Just swap it over.  In doing so you'll tension the camchain,  providing nothing is seized.

[Tiny Tim]

Cheers Mike.

[Tiny Tim]

Spot the difference
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Clearly the bolt removed is bigger and not an original part.
Not sure what to do next.

Any suggestions?

Cheers
Tim

[royhall]

Looks to me like the engine casing has been drilled out and re-tapped. Those bolts tend to seize in place if not greased up and moved occasionally.

Looks like the PO has stripped the thread out and done a home made repair. You may need to get someone with a lathe to turn you a special bolt to fit, a copper washer under the locknut and a turn of ptfe on the threads by the locknut will probably stop any leaks.

Somebody on here will probably know a tested fix as its a common problem. Sounds like Mike may know as he mentions it being seized.

Pretty sure your new bolt isn't going in there any time soon though.

[Tiny Tim]

I've put the old one back in for now and will have a chat with a couple of engineering shops nearby.
Onwards to the next issue.
Cheers
Tim

[mike the bike]

When I mentioned seizing, I was referring to the horseshoe shaped tensioner arm that transfers the force from the spring at the front to the slipper blade at the rear of the engine.   Also the plunger that pushes the horseshoe thingy. 
I would go along with Royhalls suggestion and get one made - in stainless preferably.

[Lobo]

This any use?

http://noxandrattles.co.uk/CAMCHAINADJUSTERREPAIRKIT.htm

Simon

[mike the bike]

That looks the biz, go for it

[exvalvesetdabbler]

The horseshoe tensioner that is prone to sticking is usually due to a very slack cam chain that has been rubbing on the pivot and peened over some of the metal.  If it's not too bad you should be able to dress the damage with a small triangular  file to free off the pivot. The spring if original may also be getting a bit tired by now.

You can test if it is free by removing the bolt that covers the end of the tunnel where the plunger goes and inserting a piece of 3mm rod. Turn the engine backwards and you should feel it move out a little.

This is how I tension the cam chain by pressing down on the end of the plunger to give the spring a helping hand during adjustment with the engine running. Pressing down onto a 3 mm rod with your thumb will hurt long before you over tighten the cam chain!

Oh - and don't forget to put some copper grease on the new bolts.


Regards
Dave

[Dave_Canada]

Hi, just saw this:
The original bolt threads into the engine case with 6mm threads and has the locking nut on an 8mm thread, the nut also holds down the washer that compresses the O-ring.
You can see that on the "new" original pattern bolt.
But that bolt is easily damaged off - you see the big nut and think it can take 8mm torque. A common fix was to drill out the remaining bolt if it snapped off but that's really hard to do on the frame with a hand drill without ruiingn the 6mm threads. SO the hole gets drilled and tapped for an 8mm bolt or some size that will fit. I don't know if your Allen bolt is 8mm or an inch size.
Anyway, this works fine and there's no good way to go back to the OEM bolt. The hole doesn't seep oil without the O-ring.
I suppose you could put a 6mm keensert in the bottom and an 8mm keensert above it but that would be quite a trick. Plus adding an O-ring recess...

[mike the bike]

Using the aforementioned repair kit will do the job nicely but I wouldn't fit it with the engine in situ.  Buy one and save it for when you next take the engine out.

[Bryanj]

From memory a 6mm keensert uses a 10mm tap so an 8 would at a guess be 12mm tap and i am not sure there is enough metal around the holes for that

[megamax]

Hi all

Anyone use the repair kit from NOXANDRATTLES.

would be good to see a pic. I have a similiar issue and looking for a solution.

cheers
Eric