Cam Chain Tensioner

[lorenc]

I adjusted the can chain last week but I didnt have a torque wrench so I guessed. It ran all week very nicely.

Tonight I was at a friends house who has a torque wrench so what was the intelligent thing to do. Readjust the cam chain and torque it to spec. The bolt broke before I was at 4.3 ft lbs. I will have to drill it out.

Does anyone know what size the bolt is so I can pick up a replacement at the hardware store?

Thanks

[cajun31]

Describe in greater detail

Lorenc,

You need to start from the beginning exactly what you did the first time versus the torque wrench. I don't think it's clear exactly what you were doing. To adjust the cam chain tension a torque wrench is not necessary. For folks to help you we need a better description of what it is you were doing.

[lorenc]

Took off the left side cover and lined up the pointer with the "C" on the steel plate. (I dont know what it is called.) I loosened the 12mm locknut then loosened the 10 mm bolt on the upper part of the front of the engine. Retightened the bolt then tightened the nut. That is the procedure the Clymers manual gave. I didnt remove the spark plugs like the manual said. I used a 10" cresent wrench to turn the crankshaft clockwise.

[Ken Talbot]

Re: Describe in greater detail

Originally posted by cajun31
To adjust the cam chain tension a torque wrench is not necessary.

A torque wrench is not necessary, but it is a really good idea so you don't over-torque the holding bolt. It is only supposed to have 4.3 ft-lbs, then only 6.3 ft-lbs on the lock nut. The high number of stripped-out tensioner bodies and broken holding bolts, is a good sign of how easy it is to go wrong with this.

[DiverRay]

lorenc,
As a caution, 4.3 ftlbs is IMPOSSIBLE to measure with a "ft lb" wrench. You MUST use an inch pound wrench, and convert so you don't over tighten it. I usually just get the bolt snug, and go about 10 degrees past to tighten, then snug the lock nut.
The bolt is a standard 6mm, coarse thread bolt.

[Winterhawk]

I'd put a 6mm helicoil in it. I've had good luck threading them to a 1/4-28 also.

[lorenc]

Nothing is easy

Ok guys, now the easyout I was using broke off in the broken bolt. Any Ideas?????

[cajun31]

Which bolt

Which bolt broke? The center bolt that you actually are adjusting or one of the bolts that hold the unit on?

[lorenc]

The center bolt that you adjust.

[cajun31]

Take it off

Take the whole assembly off the bike to remove the tension and then work on it.

[cajun31]

By the way

Follow the instructions for tightening the tensioner before you remove it. That way whether you are able to fix the existing unit or have to buy one on Ebay or someone on this site at least the bike will be ready for it and you won't chance slipping a tooth on the cam chain which would cause more problems.

[lorenc]

cajun

I did put the pointer @ "C" before I started. I already took off the assembly off the bike and have been working on it at the bench. It may be a long nite.

[cajun31]

That sucks

It really does suck when the bit breaks off in the bolt. I have had some success with a smaller drill bit attempting to wall out the broken bolt, but you really need to be careful as it is so easy to get off center and screw the whole works up. You might want to try applying heat then soak it with penetrating oil.

[cajun31]

Here is a buy it now on Ebay

http://cgi.ebay.com/ebaymotors/1978-...ayphotohosting

[Ken Talbot]

Re: Nothing is easy

Originally posted by lorenc
Ok guys, now the easyout I was using broke off in the broken bolt. Any Ideas?????

Now it's time for a diamond burr in a Dremel tool. Bore it out, and keep boring till you've just about bored away all of the bolt too. Most times, e-z-outs break when you drill too small a hole in the broken off bolt. Grind out the bolt till you can get another e-z-out in there that is just about as big as the bolt was in the first place. Don't worry about hacking up the body of the tensioner a bit because you'll be drilling it out for a heli-coil anyways.