Manual Cam Chain tensioner vs Mechanical

I'm leaning towards the manual, as the design makes me think it will last forever.  As opposed to the ratcheting mechanical, which the teeth may strip over time from engine vibration.  The bike is a 2012 ktm 250 xcfw.  The stock hydraulic unit is shot at 170 hrs, the mechanical unit I'm looking at is from Dirt Tricks.  Anyone have one of these installed on their bike who can speak on how long it will last?  Thanks

I read a lot about the manual adjusters and I do know that many guys use them successfully, but my honest opinion as a mechanic for many years who has been countless motors these things make me cringe.  Cam chain tension is pretty important, and I believe you are much more likely to screw something up by having the adjustment on one of these be off than the chance of some catastrophic engine failure due to a stock tensioner coming apart.  The worst I have ever seen happen with a stock tensioner is some noise, which is obviously fixed by a new tensioner.  Even a little too tight on a manual adjuster can be disasterous for an engine and IMHO not worth the risk.  

Again, this is my own biased opinion but I have spent a couple decades first as an auto mechanic and then bike mechanic (only do it on the side now) and I owned two retail/service shops for 5 years in the middle of it.  I always tout OEM parts for just about everything.  I was fairly young when I started my shops and was all about aftermarket everything, but after selling and installing aftermarket stuff for so many years I will go OEM on just about everything.  Motocross bikes are not like a Honda Civic, these machines are built with the use we put them through in mind and while the factories and engineers do sometimes get something wrong, overall you can usually be assured that that engineers that design these bikes for a company that has spent decades and millions of dollars and has millions of cumulative hours of their products being used in the real-world as feedback with which to design their products has got it right.

I know plenty of guys run these successfully but I would not touch one with a ten foot pole.  I have taken out hundreds of chain tensioners during valve adjustments, top-end rebuilds and motor rebuilds and I have never seen the teeth stripped on one of these before.  I always recommend a new cam chain and tensioner as part of a routine top-end rebuild as they are wear items but see no need to deviate from stock on these items.

How difficult of a job is properly installing a manual cam chain tensioner? Harder than doing fork seals?

How do I tell if the cam chain has been over stretches and needs replacement? How far should I be able to pull if off the teeth of the sprocket before it needs to be replaced? Thanks

Edited by idratherberiding

Actually on my '08 after freshening up the a top end, I went five laps and at the end of a bunch of whoops it let loose.  After taking it apart I found there was no oil in the hydraulic tensioner.  I chalked it up to something I did wrong and immediately bought a manual tensioner and it worked great.  For me, the trick was to only adjust it with the valve cover off making sure there was a slight amount of chain tension. I have no idea what the problem was with the stock tensioner but have heard I am not the only one that has had that happen. 

This topic is like the "which engine oil" is best... various opinions. 


I ran a manual cam chain tensioner on my 450R all last season, I checked it after every race and most hard practice sessions. For trail/woods guys they may be fine (set/adjust and forget).. but if you're twisting against the limiter on a fairly regular basis, you should/need to check it after every race which is a total pain in the ass.. 


I just installed a brand new OEM tensioner back in my 450R for this season, and I know some factory race teams do the same thing. I think the stock/OEM tensioners that you hear all the horror stories failing have been in the bikes for 100's of total hours. I will change my OEM tensioner at every top end. Very cheap, and takes all the guess work out of it.


That's just me... 

I hear that. If it were a 40 dollar part, ID do the same thing. But for me it's a 120 dollar part. I'm still undecided on the dirt tricks or manual. Everyone is making great points. I'm sure the dirt tricks ratcheting unit is much better than my OEM hydraulic unir, which was shot at less than 146 hrs

The stock/OEM tensioner is $58.22 for 2009 450R on Motorsport.


Cheap insurance, and easy to replace at every top end rebuild, or once per year whichever comes first.


Pro's and cons either way.. I personally like the fact of "install and forget about it".. I prefer peace of mind over guess work any day.



Ty for your input

Edited by idratherberiding

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