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Offline Ebrimmer

Occasional Clunk when Shifting
« on: August 01, 2020, 05:00:02 AM »
I found this in the Can-Am forums which seems to describe exactly the clunking sounds I hear when shifting to high or reverse and then depressing the throttle.

Has anyone opened up their cfmoto engine to see if this same thing is happening?

It would solve an annoying problem which drives me crazy trying to find its source.

Can-Am's are also notorious for a clunking sound they call the Can-Am clunk.

"Thought I would share some information that I just learned.

I was able to identify where the clunk sound is coming from after you shift into a new gear. On the top of the shift drum assembly is the index washer (kind of looks like a 5 pointed star), alongside that is the index lever with a roller on one end that goes into the indents of the index washer with a strong spring for tension pushing the roller into the indents. When you shift the shift drum is turned and the index lever is pushed away and then starts to go into the next indent. The clunk that many people have complained about is when that index lever has started to go into the next indent but does not go all the way and then when you start to give it some throttle it clicks the rest of the way into the indent and makes that heavy clunk sound. I don’t see any way to remedy this, sometimes the index lever will slip in the way it should and then the next time it won’t, but the good news is that it does not appear to be causing any damage."

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Offline Ebrimmer

Re: Occasional Clunk when Shifting
« Reply #1 on: August 01, 2020, 05:41:20 AM »
I found this in the Can-Am forums which seems to describe exactly the clunking sounds I hear when shifting to high or reverse and then depressing the throttle.

Has anyone opened up their cfmoto engine to see if this same thing is happening?

It would solve an annoying problem which drives me crazy trying to find its source.

Can-Am's are also notorious for a clunking sound they call the Can-Am clunk.

"Thought I would share some information that I just learned.

I was able to identify where the clunk sound is coming from after you shift into a new gear. On the top of the shift drum assembly is the index washer (kind of looks like a 5 pointed star), alongside that is the index lever with a roller on one end that goes into the indents of the index washer with a strong spring for tension pushing the roller into the indents. When you shift the shift drum is turned and the index lever is pushed away and then starts to go into the next indent. The clunk that many people have complained about is when that index lever has started to go into the next indent but does not go all the way and then when you start to give it some throttle it clicks the rest of the way into the indent and makes that heavy clunk sound. I don’t see any way to remedy this, sometimes the index lever will slip in the way it should and then the next time it won’t, but the good news is that it does not appear to be causing any damage."
After thinking about this more I'm going to do two tests today to see if this is the cause:

1) change gears and then rock the machine back and forth with butt scooch's and lunges to listen for an engagement. Then press throttle to see results.

2) if that doesn't provide the movement needed get off the quad and push it forward or backward by the handle bars depending on what gear I just changed into and listen for engagement. Then press throttle to see results.

Fingers crossed that I'll have more clarity as to what is causing my clunk sounds during these transitions from forward to reverse and vice versa.

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Offline Ebrimmer

Re: Occasional Clunk when Shifting
« Reply #2 on: August 03, 2020, 05:23:08 PM »
I found this in the Can-Am forums which seems to describe exactly the clunking sounds I hear when shifting to high or reverse and then depressing the throttle.

Has anyone opened up their cfmoto engine to see if this same thing is happening?

It would solve an annoying problem which drives me crazy trying to find its source.

Can-Am's are also notorious for a clunking sound they call the Can-Am clunk.

"Thought I would share some information that I just learned.

I was able to identify where the clunk sound is coming from after you shift into a new gear. On the top of the shift drum assembly is the index washer (kind of looks like a 5 pointed star), alongside that is the index lever with a roller on one end that goes into the indents of the index washer with a strong spring for tension pushing the roller into the indents. When you shift the shift drum is turned and the index lever is pushed away and then starts to go into the next indent. The clunk that many people have complained about is when that index lever has started to go into the next indent but does not go all the way and then when you start to give it some throttle it clicks the rest of the way into the indent and makes that heavy clunk sound. I don’t see any way to remedy this, sometimes the index lever will slip in the way it should and then the next time it won’t, but the good news is that it does not appear to be causing any damage."
After thinking about this more I'm going to do two tests today to see if this is the cause:

1) change gears and then rock the machine back and forth with butt scooch's and lunges to listen for an engagement. Then press throttle to see results.

2) if that doesn't provide the movement needed get off the quad and push it forward or backward by the handle bars depending on what gear I just changed into and listen for engagement. Then press throttle to see results.

Fingers crossed that I'll have more clarity as to what is causing my clunk sounds during these transitions from forward to reverse and vice versa.
Its been several days where doing step 1 has completely stopped the clunk. This shows me the problem is the shifting and not the clutch or drive train. Sure, I look odd rocking my machine back and forth but there is something satisfying of having a smooth throttle experience instead of having a clunk.