Not sure who's pic you're comparing to, but if it's mine, I chopped my prototype down a ton when Mark and I were putzing around coming up with the final dimensions and such. I still use that shortened version of the plunger. I'm not sure if Mark uses the exact same size setup everytime, because it wouldn't be important. I'd say if you have the adjustment done per the instructions, how much of the plunger's threads showing isn't indicative of a problem. But...nothing wrong with being cautious. Just check and double check.

 

I've got about twice the threads showing as you have.

Good to know. I'm sure the amount of chain stretch factors in, too. I've got about 900 miles on my bike, so I'd like to think the chain is still nice and tight. I installed the tensioner at the same time I adjusted the valves, so I could see that the plunger is pushing on the chain guide. My concern is that I have so much thread showing (indicating that the plunger isn't very far in) and that when I followed the procedure in the instructions, it wasn't that easy to turn when tension was applied to the cam chain. It was noticeably more difficult to turn the bolt when I let off the tension via the crank bolt, so I figured I was on the right track.

 

My chain has very little slack. I measured per the manual and it was right in spec with about 7K miles on it. And I believe Mark and maybe others have mentioned making adjustments which were very slight (something like 1/4 turn of the adjuster).

 

If I remember right mine sticks out quite a bit also like it is pretty long. I have ran mine from a little loose to a little tight to get it right and you can tell by the sound where you are at. Too tight and you get no noise at all. From Marks description it should make some noise when cold and clear up and sound good when warm, That is how mine is adjusted now.

 

FWIW, I just measured and I've got 27mm or about 1-3/32" of thread showing.

 

I use an 80 mm bolt, but had a few that were more like 85 mm when finished. Fastenal got me a bunch of 120s by mistake, so they cut them down. The length sticking out will vary a bit, but it can be cut down like TNC did with the prototype. That's the advantage of the jam nut on the adjuster nut. You can shorten it up if you please, plus, of course, allow replacement of the O-ring seal if needed.

Don't get too wound up on how much bolt sticks out. It will be different on almost every bike. There are the machining tolerances of the case height, cylinder height, and even the cam journals. If each is slightly low versus a bike with each being slightly high that could add up and that will make a bit of difference in the length of thread sticking out. Not much, but some.

You guys think I should go to a 70 mm bolt?

 

Yes. Any reason not to?

 

Only if a rider runs out of threads for adjustment. I had that on one 550 Kaw. I'd rather have the bolt too long than too short. As an Industrial Technology teacher I am for ever telling my students to leave a bit of material - "it's easy to take off a bit of material, near impossible to add it back on."

I'm thinking I'm going to stay with the 80 and let the owner cut off the bolt if they wish. About the time I cut the margin down tight someone's gonna need a longer bolt and they'll probably be in Latvia or Thailand.
I'd hate to have to send a single bolt to Europe or other parts of the world - $13! Even in the U.S. the postage is more than the cost of the bolt.

 

I too just installed the Krieger Cam Chain Adjuster the other day. I did the cold setup and it is was immediately quieter than the stock automatic tensioner. I now think the stock unit was working correctly, but it is not as precise as the Krieger unit. After today’s ride I did the adjustment hot, I only finger tightened it in about 1/8 turn from the cold setting. The bike is nice a quite. I am very happy with the result. This is the first non-stock modification to my new to me 2007 KLX250. I may up shortening the bolt to give a little more finger room for fine tuning later, but for now it is fine.

People who are concerned finger tightening is not enough, just do not understand how much a screw can amplify torque to force. An 8mm screw with 1 foot pound torque can produce almost 200 pounds of force (according to one on line calculator).

My thanks to Mr Krieger and this forum.

 

serious question. why even bother? is this necessary? thanks- Hunter