Wierd jerking at idle in gear.

deathjam4

Member
Hey all so quick question i am preaty sure i know the answer but want a second opinion.

Friend of mine recently bought a used fz6. I had to install a chain and give it a once over and did some basic maintence. I installed the did x2 pro chain on it pulled the wheel to check bearings and clean the grease from the old sliders and gear teeth since it had new jt sprockets. I reassembled and properly adjusted the chain but for some reason while in gear the bike started herk a jerking while it was idly turning in gear while in the air.

Went away with a bit of throttle but would persist till i pulled the clutch in and then came back when i released it. Did this in all gears i tried. Now my first thought was maybe i screwed the chain up but it rolls smooth and steady at all speeds and nothing was holding it or kinking which left the engine.

I figure its likely the clutch since the lever setting was past its maxamuim extension with an after market 6 setting clutch lever which i told him to toss in the trash and put the stock one back on.
Am i on the right track or am i chasing the wrong leed. Also its missfireing on cyclinder 3 which i suspect is a bad sparkplug or plug wire like mine was.( fuel was coated on the air box inside directly above cyclinder 3) the bike also aperently has a power commander installed so not sure that has anything to do with any of this. Not sure if its been properly adjusted to this bike.
 

Motogiro

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You will always get a jerky response when there is no load on the rear wheel while in gear. There will be slack in the chain and especially when the engine is missing.
I think your greater concern is the miss and you might want to do a leak down test once you confirm you have proper spark and fuel.
 

Motogiro

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Also if there is a burnt intake valve on #3 it could explain why you have fuel above the #3 intake. Since the PC fuel controller is responsible for fuel, it would be smart to disconnect it during trouble shooting.
 

trepetti

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Hey all so quick question i am preaty sure i know the answer but want a second opinion.

Friend of mine recently bought a used fz6. I had to install a chain and give it a once over and did some basic maintence. I installed the did x2 pro chain on it pulled the wheel to check bearings and clean the grease from the old sliders and gear teeth since it had new jt sprockets. I reassembled and properly adjusted the chain but for some reason while in gear the bike started herk a jerking while it was idly turning in gear while in the air.

Went away with a bit of throttle but would persist till i pulled the clutch in and then came back when i released it. Did this in all gears i tried. Now my first thought was maybe i screwed the chain up but it rolls smooth and steady at all speeds and nothing was holding it or kinking which left the engine.

I figure its likely the clutch since the lever setting was past its maxamuim extension with an after market 6 setting clutch lever which i told him to toss in the trash and put the stock one back on.
Am i on the right track or am i chasing the wrong leed. Also its missfireing on cyclinder 3 which i suspect is a bad sparkplug or plug wire like mine was.( fuel was coated on the air box inside directly above cyclinder 3) the bike also aperently has a power commander installed so not sure that has anything to do with any of this. Not sure if its been properly adjusted to this bike.
Don't be too hasty in tossing the adjustable levers. There are some REALLY good ones out there (Pazzo and CRG come to mind), that are WAY better than the stock levers.

Step 1 of problem solving.... figure out the problem.
 

trepetti

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I think running the bike in gear on the center stand is dangerous.
I don't disagree, but I am curious as to why you think that.

The few times I have done it (at idle only) I was concerned about any jerkiness kicking it off the center stand. I know the extra chain slapping can't be good. What other risks do you see?
 

Gary in NJ

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I don't disagree, but I am curious as to why you think that.

The few times I have done it (at idle only) I was concerned about any jerkiness kicking it off the center stand. I know the extra chain slapping can't be good. What other risks do you see?
Exactly what you observed. Also, loose items getting caught in the chain. When I was a kid I watched as a friends pants got caught up in the chain, dragging him into the bike, knocking the bike off the stand and driving him into a wall. Luckily the pants were torn to shreds and his injury was limited to the spinning tire burning his leg and torso.
 

trepetti

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Exactly what you observed. Also, loose items getting caught in the chain. When I was a kid I watched as a friends pants got caught up in the chain, dragging him into the bike, knocking the bike off the stand and driving him into a wall. Luckily the pants were torn to shreds and his injury was limited to the spinning tire burning his leg and torso.
I'm wearing shorts from now on!!!!!!
 

deathjam4

Member
Never once......good. I wonder if anyone has had it happen TWICE :)
Well its not really a safety thing if you know what your doing. But this is all kinda off topic so please lets get back to the oringal issue and forget about safety concerns lol.

And as for the chain i said it was properly adjusted and brand new so there is no issue there. I rolled the wheel by hand and it was not kinking anywhere. So preaty sure its related to the engine. Might be the miss fire or the commander pro settings.
 

TownsendsFJR1300

2007 FZ6
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Re the chain, how much up and down play did you set it at (on the center stand)?

Re cylinder #3, have you checked for spark, compression?
A leak down test (if you have spark) would help in diagnosis.

.
 

trepetti

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Well its not really a safety thing if you know what your doing. But this is all kinda off topic so please lets get back to the oringal issue and forget about safety concerns lol.

And as for the chain i said it was properly adjusted and brand new so there is no issue there. I rolled the wheel by hand and it was not kinking anywhere. So preaty sure its related to the engine. Might be the miss fire or the commander pro settings.
First, disconnect the Power Commander per the recommendation in post #3. That will split the problem in two and you will know if you are troubleshooting a Power Commander problem or an FZ6 problem. If the problem persists, swap the #2 and #3 plug wires and see if the wet spark plug problem moves.

I was going to chime in with a final word about center stands. Something like 'The people who get hurt the worst in situations are the ones who 'know what they are doing'. They are far less cautious around machinery then the less experienced, who still have a profound respect for the dangers involved.

But I decided not to say anything. :)
 

Motogiro

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Funny, I just saw this, this morning. I think it's good mental exercise to listen and be open. No matter how experience I become I acknowledge there is always something new, life or riding will teach me.
 

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