Cam chain tensioner bolt

[watty51]

Hi all,
Having just spent a lot of time carefully extracting a broken cam chain tensioner bolt, I am ready to fit a new one.

I have checked the thread after some trial fitting, luckily it’s still in good shape and tightens nicely.

Before I start the engine how far do I need to screw the new tensioner bolt in ?

It’s on a Cb350f.

Thanks

[Bryanj]

It screws in till it clamps the tensioner rod

[robvangulik]

+1, and it does NOT need any real torqueing down, so keep that thread in good health!

[gtmdriver]

The tensioner bolt does not actually adjust the chain tension. There is a spring loaded plunger inside which is supposed to do that automatically. The tensioner bolt is there simply to lock the plunger in place once its done the adjustment so it just needs nipping up lightly. The lock nut then secures the bolt.

[watty51]

Thanks for the replies,

So the next step is to follow the guide as set out in the workshop manual, (as pictured), job done.

[Bryanj]

Nope thats one bit of the manual that is utter shite.
Loosen the locking bolt, put pressure on kickstart untill engine is just trying to turn and at same time lock up bolt then nut.
This assumes hoseshoe is moving and adjustment plunger/springs work ok

[watty51]

Thanks Bryan,

Glad I asked now. Will give it a try later.

I’m just in the process of removing cylinder head cover, then removing cylinder head so I can get some head work done,  thread repair of all spark plugs to start....

You can’t beat experience

[Winterfield]

I would be very interested to hear about your experiences getting the broken one out. I have three sets of engine casings, all of which have broken tensioner bolts stuck in them.

My plan is to use a left handed drill bit, and to try and have a collar machined to use much like a self centering drill bit.

[Bryanj]

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

[watty51]

Well it’s a job I found that needs lots of time and patience...

Drained oil, took off the oil filter housing to make a bit more room to get my drill in.

The m8 part of the bolt was complety sheared off, so all was left was about 15mm of m8 thread.

I use a drill bit set called Dormer which have sizes that go up in 0.5 so after using plenty of wd40 began with a 1.5 drill bit on a slow speed setting to get a hole started into the middle of the bolt. Then took a 2.0 drill and made the hole larger, and carried on in 0.5 increments until I had a hole 4 mm and about 15mm deep into the bolt.


Again wd40 and left overnight to soak in.

I used a screw extractor from a kit cht526 Clark and tapped that into the hole and gradually turned it again using plenty of Wd40 until the bolt came out.

Maybe I was lucky that the hole thread was not damaged. I read from a earlier post that Bryanj use to drill them out said it was a b**tard of a job, he was right...good luck