Jerry I had the M6...it had been so long ago. It was on a Baker DD6 set up with the 27 tooth comp sprocket. Called Baker and they did not recommend a auto tensioner, but no reason given at that time. Installed their larger shoe. Just seemed at the time that this happened to me, all the builders I talked to did not recommend a auto tensioner to a built engine. They all had the same reason.....when you let off the throttle with a more powerful engine, the chain slacks and the tensioner takes up that slack which could make the chain too tight.
Looks like the 125 where you can set the preload...is the way to go
I'm not certain what they meant by the comments about decel chain slack, since the Hayden or HB125 are free to move and maintain a more constant tension. Their comments make a lot of sense with the ratchet type from Harley, however.
The preload is adjustable with the Hayden as well, using the supplied shims under the spring. The only reason I stuck with the Hayden instead of the hydraulic version was my concern about the "crud" from the clutch possibly affecting the hydraulics. It works like a valve lifter, so I assumed all that grit and crud in the primary fluid could easily plug something. I haven't heard anyone complain about that in the real world, but in my mind it was a concern.
Jerry
Author
Topic: primary auto tensioner (Read 7855 times)