Front camchain tensioner


Front camchain tensioner

Postby oilheadron » Sat Sep 04, 2010 3:48 pm

If you remove the rubber blanking plug can you see the end of the tensioner rod directly?? If so, how close to the end of the hole should the end of the tensioner be in a healthy motor??? TIA.
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Re: Front camchain tensioner

Postby EMS » Sat Sep 04, 2010 8:11 pm

:D :D :D That is a tough one to answer. Mainly because there are probably only one or maybe two people in the whole world who ever used this approach to diagnose the cam chain condition.... :wink: The service manual decribes how to determine the "service limit" of the cam chain. While I personally find it a little cumbersome to follow that procedure, because it calls for use of a spring scale to stretch the cam chain over the two sprockets with a load of 4.4-22 lb and measure the distance between the outer diameters of the center holes of the cam sprockets - and it should not be no more than 170.7mm (6.72 inch) :roll: :roll:, the chains are readily available new for relatively little money and once you are that far with disassembly, you may as well replace the darn thing! If you are confident that the chain is O.K., set it up for proper tension, if necessary, pull the tensioner up (or back) with a pick and thighten the slack of the chain completely out while holding forwad rotation load on the cams and then measure to the tip of the rod in the hole.
Another indicator of the cam chain being too long and need replacement is the alignment of the sprockets. If you can not align the marks on both sprockets with the cylinder head surface as described in the manual, it is time to throw out the chain.
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Re: Front camchain tensioner

Postby oilheadron » Sun Sep 05, 2010 3:00 pm

Cam chain condition is not what I'm interested in. I have a stripped adjuster bolt hole and some sort of foreign object crammed into the hole where the rubber plug is supposed to be. I'm trying to correct all this without tearing anything up (or pulling the head on an otherwise healthy motor)!!

P.S. What I'm seeing is maybe an eight of an inch below the opening where the rubber plug should be. Could I be seeing the end of the adjusting rod that close????? It doesn't seem like enough room for a rubber plug to bite.
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Re: Front camchain tensioner

Postby EMS » Sun Sep 05, 2010 9:12 pm

If memory serves me well, I did shorten the rod when I put the axial "adjuster bolt" in. It was a few years ago, and I don't have that motor anymore. If you look at that little protrusion and figure that the stock adjuster bolt has to clamp the rod, the tip of the rod is pretty close to the end of the hole. The plug was part-number 91208-422-003 and it was described as 11.5x7, which should mean 11.5mm in outside dia and 7mm thickness (a little less than 1/3 of an inch).
If your adjuster bolt is stripped and can no longer hold the rod and the cams are loaded against the regular rotation, i.e: the bottom of the chain is stretched between the gears, the tensioner is flattened against the tension of the spring and the rod is pushed all the way forward. It may be possible that you see it that close.
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Re: Front camchain tensioner

Postby daves79x » Tue Sep 14, 2010 4:12 pm

Drill the hole and install a Helicoil - it can be done in place with a right-angle drill. Work very carefully. You'll have an issue with the o-ring on the adjuster bolt sealing, but I've gotten the several I've done to seal OK. Then install a new end plug with a bit of case bond and you'll be all set. Sorry I'm late on this topic also.

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Re: Front camchain tensioner

Postby oilheadron » Tue Sep 14, 2010 5:29 pm

What I did was to tap the hole for a 10mm bolt (I had a really nice chrome internal allen-headed bolt laying around) and put a rubber plug in the front and and so far it's working pretty good.
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