I solved the/my "noisy" engine problem (and it's not what you may think it is)

The problem is stripped teeth on the cam chain tensioner causing the chain to slap on the guide which then slaps on the adjuster pin. Don't be fooled if you've checked it for adjustment; It'll trick you and you need to bench test it.

This IS the ticking clattering sound that is loudest at idle speed and seems to go away as engine speed is increased. This happens because at idle, the engine is ticking over and theres constant slack and tension in the chain, but as engine speed is increased, the piston is driving the chain and it's always "taught" on the back side where the tensioner is.

Here's my story;

My bike (2009 SMR 510) developed noisy, ticking sounds in the engine after approximately 1000 miles. People have described it as a mechanical noise. I have read every thread I could find on why the Husky motor would do this (and apparently alot of them do).

In my search, I have read that the "noisy engine condition" is attributed to everything from a worn timing chain to a busted water pump to the auto decomp laying on the cam to the valves being out of spec etc (they are all good reasons and probably true for some). I also read that it's just normal/typical for the Husky motor to sound this way. I just couldn't accept that, so I checked everything 10 times or more and came up with no solution. The engine still ticked and clattered and made alot of mechanical noise.

The ticking sound was driving me crazy as it sounds like something is wrong with the motor AND the fact that it didn't do it for the first 1000 miles told me there HAD to be something else not quite right.

Here's what I did;

I used a screw driver as a stethoscope, putting the handle to my ear and the blade end on the running motor. When I put the "stethoscope" directly on the cam chain tensioner the ticking/pinging was loudest.

I thought to myself; I've checked/adjusted this thing umteen times, why/how the hell is it making such a racket!!!??? I had it out previously and checked both it and the chain for proper adjustment.

So... determined, I removed it from the motor once again and took a VERY VERY close look at it. What I saw is that the tiny little teeth on the adjusting pin were rounded off just enough for it to slide past the detent and be pushed all the way back in when the motor is running.
But how???

It's tricky because if you push on it with your finger, it will stay put. If you apply constant steady pressure to it, it will stay put (depending how rounded off the teeth are). However, if you tap it on the bench (like as if the chain were slapping it with the motor running) the rounded teeth won't hold under the pounding/vibrations and the adjuster pin slips past the detent and gets pushed back leaving the timing chain slapping in the wind.

What's worse, is that the spring keeps pushing (reloading the adjuster pin) back against the chain guide if/when there's any slack in the chain as the motor rotates, and then the chain pushes it back again and the cycle repeats continuously. Very interesting I thought to myself.

BUT... I had to be sure, so I ran another test;

I reinstalled the cam chain tensioner on the motor and left the spring and screw out of the back of it. I then stuck a thin probe into the back of it and pushed the adjusting pin all the way in and up against the chain guide which then was pushed all the way up against the chain itself; which is where it should be. I then cranked the motor over with the starter several times.

I then re-inserted the probe into the back of the chain tensioner (where the spring and screw would normally be) and pushed in on the adjusting pin. Sure enough; I was able to push it all the way back in up against the chain guide and then all the way up against the chain. I did this several times with the same results.

Now even though this was pretty conclusive, I still needed to be REALLY REALLY sure; So I ran another test;


I took a very fine, small hack saw blade and sort of cut an edge back into the teeth enough for them to catch on the detent.

It now passed the bench test.

Satisfied, I re-installed the unit on the motor. I then took my probe and pushed the adjusting pin in all the way up against the chain guide which was then pushed all the way up against the chain itself and then re-installed the spring and screw. With my fingers crossed, I started the motor.

OMG, the thing was quiet as all get out. Like new!!! That's right: No More Noise. The motor now just sounds like a normal motor with out all that clattering, pinging and clicking ticking going on.

Hope this helps some one.

Sorry no pics, but it's pretty self explanatory once you get to it.

I thought the 09's had a revised cam chain tensioner that was more reliable and durable?

Excellent work Redrims.

Rep also given.

I thought I read that too, but what's funny is I also have a 2008 510 with similar mileage (both bought new) and its never had any issues with the chain tensioner nor has it ever made any ticking or clattering sounds.

Also, from the outside, the chain tensioner housing looks identical on both bikes. It's a simple device; I wonder what they improved!?

Anyway, the teeth are very fine and easily stripped. If even one misses the detent and gets rounded off, the continuous cycle of being reloaded by the spring and then pushed back by the chain pressure contributes to the destruction of the other teeth.

The motor just purrrs now.

Looks like you may be in the market for one of these. http://www.bigborethumpers.com/tensioners.html

I have one on my TE610, and I'll be looking at the used TE310 I just bought. Don't know if I have an issue or if it will fit, but I'm betting it will. I'm new to the smaller TE's, but I have noticed they seem to have a lot of engine clatter compared to the 610. Thanks for the research and info.

is this what you are talking about? number 11 (8000 67744 Complete tensioner)

ah_huat;

Yes, that is exactly it.

Motogo1;

Thanks for the link. I will look into that. Interesting what they had to say about auto and hydraulic chain tensioners - made sense to me after this. The way I ride my SMR (Lots of hard accelerations and decelerations, bouncing off of redline often), sounds like I could possibly benefit from having a manual tensioner.

Thank you very much for the info. My 510 is making this clatter too and i've been unable to track down the noise. I'll definitely check those teeth ASAP.

I have though about a mcct for my Husky. I knew of the one available for the 610 but haven't given it much thought, untill now.

Someone needs to chime if the 610 cct will fit the dohc models.

Nice detective work, and thanks for sharing.

I actually work at the company that was mentioned above. I am not trying to advertise on here and if this is against the rules then let me know and I will delete this message. We do have the tensioner for the 610, but we don't know if it fits the smaller DOHC bikes. If somebody is willing to send in their stock tensioner we can compare it to the tensioners that we make and see if one is compatible. If somebody is willing to do this then pm me and I can tell you where to send it to. Once again if this is a no no then I will delete this post.

I'm not sure I can send mine in just for the heck of it... but I could take some precision measurements and send them to you?

I have a spare that I could send in from my 2008 TXC...

Let me know where to send it.

Later,

Nice work and report, as far as the interchange between the single cam 610 and the twin cam motors, I checked the Halls online catalog and found this:
08 SM TE TC TXC 250-510 PN 8000 67744
08 SM TE 610 PN 8A00 68908

To me this still does'nt mean the manual adjuster wouldn't work for both motors, because the difference in the ACCT units may be one of travel length. When looking at the tensioners without removing them, they look alike.
I could (later) pull the ACCT off my 450 for a closer comparison to the 610 adjuster.

Nice work. I wonder if this could a problem I'm having with my 2010 TXC250. It only have 10 hours on it, but it has picked up a noticable ticking noise at idle.

Alright thanks Coffee. I'm just trying to help out the growing Husky community.