[Phlakaton]

Quick question -

When I let off the throttle in any gear from 2nd to 5th I get an annoying lurching effect.  I have an '08 Iron Bullet.  The only time it isnt obvious is when I am going a touch too fast for the particular gear I'm in.  But when I start to drop to lower speeds towards the next gear the bike seems to want to go but not.  Lurching!  It's almost like it's getting a bit of gas and then isnt.

Any ideas from the pros?

[ace.cafe]

Make sure the chain is adjusted right, because that tends to cause lurching if it's loose.
Also keep the rpms up a bit, because if you're lugging at too low rpm for the gear, it's bad for the engine.

[The Garbone]

Acceleration or deceleration lurch?    

Does it happen after letting off the throttle and before, during or after clutch pull?  

It could be that your cable and throttle grip needs some lube and is not returning fast enough.  I would also check routing of the cable too insure it moves freely.

[Phlakaton]

its a deceleration lurch.  I can be going plenty fast enough for the gear I'm in when it does it so it's not a slow speed issue. 

Thank you for the suggestions.

[Phlakaton]

I took a look at the chain and it does seem loose... I wasnt sitting on the bike -it was on the center stand.  I didnt measure the distance but eyeballing it seems like a couple inches play.

Here is a question - since I am a noob on motorcycle maintenance - what is the best way to tighten a chain??

[Vince]

     First lube the chain. Go inside and have a cup of coffee. Come back in 1/2 hour to allow the lube to soak in. Chains have tight and loose spots. Spin the rear wheel to find the tightest spot. Adjust at  that spot to have 3/4" to 1" of play, midway between the sprockets, on the bottom run, with you sitting on the motorcycle.

[Phlakaton]

great info.  one thing though... where do I adjust the tension?  do I have to take that case off that's next to the clutch arm?  I was looking in the manual and that seems like what I need to do... oil removal and refilling and all that?

or is it that odd bronze looking plate behind the axel nut?  it looks like you can rotate it with those shallow curved teeth against the notch that is on the swingarm.

is this easier than I'm imagining?

[Vince]

     You have to loosen the two axle nuts and the brake panel anchor nut. This is below and just forward of the axle. Rotate the cams on both sides of the wheel to adjust tension. With the cam set up you might not be able to exactly adjust the chain. A little loose is better than a little tight. Get both cams even. Tighten the first axle nut. Re-check the cams to make sure they didn't move. Tighten the next axle nut. Re-check the cams again. Then tighten the anchor nut. As a final check sight down the lower run of the chain to check for straightness. A kink off the rear sprocket means you have to re-check your work.

[Rick Sperko]

Correct me if I am wrong, but I think Snidal indicates you should have 2" when on the centerstand, less when sitting on it.

-Rick

[PhilJ]

Correct me if I am wrong, but I think Snidal indicates you should have 2" when on the centerstand, less when sitting on it.

-Rick

If that is what Snidal's says, it's wrong. It all depends on your weight. The only way to set it is to set on your bike, adjust so that the chain has the correct slack with your weight. Then measure on your center stand the slackness. That will be "your" adjustment measurement.

[Vince]

     If you want to get real technical you would remove the shocks. Then move the wheel until the the centers of the front sprocket, swing arm pivot, and rear axle are in a perfectly straight line. This is the point that the chain is at it's tightest. It will be looser at every other position. Adjust here (use the same method I described above) to have about 3/4" play. Now put the shocks  back on and measure the play. What ever this new measurement is, paint it on the garage wall to remember it. Afterward adjust to this figure.
     At least check it with you sitting on the bike. Your weight will bring the three centers nearly in line. Also, this is the way you normally ride the bike, so the adjustment will better reflect real world conditions.

[chumma7]

Many many miles ago, I had a buddy measure my bike's chain slack while I sat on it. I adjusted it to be exactly at 3/4" with me on the bike. When I got off the bike, the slack increased to 1.5". Since then I have always used 1.5" as the figure to adjust my chain by.
The chain now has 16k miles on it and hasn't needed any adjustment for 12k miles. This sort of chain performance is coming from me.. somebody who drives the hell out of his bike. The secret is proper maintenance. I lube my chain sparsely (but adequately) every 200 miles and clean & lube whenever dirty. If i find myself caught in a rain storm or the chain has gotten wet, I make sure to dry and lube it after wards. The same goes for cables. It's a simple part of motorcycle maintenance which doesn't take much effort but goes a long way.
I've seen chains last 3k miles due to lazy maintenance (which kills expensive sprockets too) or 20k+ miles with proper maintenance.

Everybody's got their preference for chain lubes. I have used a couple before, including waxes which i did not like. The lube that Ive been using for 16k miles on this chain has been motorex 622 off road. I use a chain brush dipped into gasoline to clean the chain.

-Chumma

[mbevo1]

I used Snidy's 2" rule and found my scrawny 145lbs didn't compress the shocks very much and the chain would rattle on the crosswise bits for the center stand... it was way too loose...

Agree with all that the bestest way is to check the tension with the rider aboard...

Mike and Stumpy in Michigan