Now I've done it. A little help please

Ok, I was being a moron and not using my torque wrench when I went to do a cam chain adjustment. I sheared the bolt off from over-tightening. It's sheared flush with the cam chain tensioner.

So, I guess my next question is. How do I fix this, do I need to find a new one on Ebay, or does someone have one sitting around that I can buy?

Am I going to be able to get the cam chain tensioner off since the bolt was tightened in there?

Any help would be appreciated.

Post edited by: austin3119, at: 2007/05/15 23:15

Shouldn't be a prob, just unbolt tensioner from engine, then try drilling the bolt out with a left hand (backward) twist drill bit. As you drill, the bit will jam and back the broken bolt right out. If it's too tight for that to work, weld a washer laying flat to the broken bolt through the hole in the washer,(you'll need a wirefeed welder for this) then a nut or another bolt to the washer and use a wrench to unscrew the broken bolt.

I haven't seen one of those bits. So I guess just go to the hardward store and ask for it. Wouldn't I need to run the drill in reverse. Sorry for the dumb questions.

Thanks

hardware, farm supply, welding supply, even some auto supplys. yes, run the drill in reverse. Or when you get it off you could take it to a machine shop, shouldn't cost more than a few bucks to get it takin out.

Remove the other bolts and slide the complete cam chain adjudster off. It should just slide. Once it's off, the bolt should just be sticking up..depending on how tight it is, you can just grap it with vice grips and pull it out. Or, do as mentioned before, weld a nut (or another bolt on) and loosen with that.

There a a few things that can be tried before you pay someone else to do it

austin3119 wrote:

... went to do a cam chain adjustment. I sheared the bolt off from over-tightening. It's sheared flush with the cam chain tensioner.... How do I fix this

:ohmy: Known as semi-permanent adjustment technique.
When lock nut was loosened and then bolt loosened, the spring-loaded internal pushrod should have automatically pushed and tightened against the cam chain. When bolt was tightened, it holds the push rod in its new position. Although sheared off, the bolt is likely still in there doing its job - but without a locknut. Would crank engine out of curiosity to see if the noise has abated .

Following successful extraction and replacing bolt, may need new gasket when re-attaching unit to engine.
gasket from Z1E .

Should be okay with repairs on existing unit, but if all else fails --
Ape's Manual unit from Z1E

Good luck!

Post edited by: Patton, at: 2007/05/16 10:10

Post edited by: Patton, at: 2007/05/16 15:19

One more quick thing -- should have mentioned this earlier :blush: (hindsight's great)

Torque specs for tightening the bolt are

78-95 in-lbs (0.9-1.1kg-M)

Just remember...when You have the adjuster removed from the bike...DO NOT turn the engine over,or even move the bike if it's in gear!Put a piece of tape over the key hole as a reminder.
With all that slack in the chain,You WILL do damage if the engine turns over!

Ditto to above advice from Sandy.

And before re-attaching unit to engine, suggest having the new adjuster bolt holding the push rod all the way inside the tensioner to minimize pressure against the cam chain while re-attaching unit to engine.

The cam chain will likely still have excess slack at this point, so refrain from any movement of cam chain (see advice from Sandy). Just loosen adjustment bolt, which allows some slack to be taken up. Then snug it back down.

After the above -- start again from ground zero with the routine cam chain adjustment.

Thanks for all the help guys. I'm getting pretty good on these bikes at making a simple job into a much more complex one.

Thanks again for the help, I'll let you know how it turns out.

By the way, my "T" mark looks more like this "+" than a regular "T" like shown in the manual. Is that normal?


Thanks

austin3119 wrote:

. . .not using my torque wrench when I went to do a cam chain adjustment. I sheared the bolt off from over-tightening . . . Am I going to be able to get the cam chain tensioner off since the bolt was tightened in there?

Did it break when you tightened the bolt, or the lock nut? I guess it doesn't matter at this point, it's broken.

As others have indicated, the tensioner itself will come off with the removal of the two bolts holding it to the cylinder.

You might be able to clamp the tensioner in a vise, and use a pin punch and hammer to tap the bolt counterclockwise to maybe loosen it for removal.

It sounds like fatigue breakage, more than overtightening caused the failure.

When you reinstall the tensioner, retract (compress) the adjuster in all the way and lock it with the new bolt before installing the assembly. Once the assembly is installed and bolts tightened loosen the adjuster bolt to allow the chain slack to be removed, then tighten the bolt.

Maybe it's obvious, but installing a tensioner with an extended locked adjuster can result in a broken assembly when you try to tighten the securing bolts.

If none of this works, at least you are started on your rebuild. . .

austin3119 wrote:

... my "T" mark looks more like this "+" than a regular "T" like shown in the manual. Is that normal?....

Yes -- the "T" or "+" mark on the advancer unit will appear just after the "F" timing-firing mark passes the fixed engine mark as the crankshaft rotates forward. This is because the ignition fires shortly before the rising piston reaches top dead center.

As noted in the "Engine Noise" thread, top dead center position of the piston is where the cam chain has maximum slack on the back side to better be taken up by the cam chain adjuster. Without the "T" mark (stands for TDC or Top Dead Center), believe would have to remove the spark plug to determine when piston is at TDC.

Post edited by: Patton, at: 2007/05/16 14:17

Post edited by: Patton, at: 2007/05/16 15:21