feels like lean surge

Hi everyone, I was hoping someone could help me with a problem Ive been having. I have a stock 07 SM with 3x3 and dynojet stage 2 kit. running a 155 main from the kit, all other jets are stock. When I did the 3x3, at a certain rpm I'll get a bit of a flat spot or lean surge, not sure what its called. Feels like the bike is running out of gas. Let it go for awhile, but I never went away. Happens at what sounds like the same rpm range. Checked it before I pulled in today, 3rd gear 36mph it started doing it when maintaining speed. same rpm all gears. Keintech fuel screw tried between 2 and 3 turns out, but I dont think its the pilot jet bc I have tried new ones, and the rpms are a bit high to be running off the pilot. Took off the side cover, still did it, taped over some of the 3x3, still did it. Rechecked and retightened clamps on intake thingys. Not sure what else it could be. My chain is wearing fast though, moved it to the furthest setting today, fourth adjustment in just a few months. time for a new chain! :D Any help would be greatly appreciated guys. Thanks.


I'm not the carb expert but I'd try raising the needle one notch. Not a pilot jet issue above off idle throttle position.

How are you adjusting the chain? If you adjust it too tight it'll cause it to wear faster. I'm always having people tell me my chain is loose.

what he said...the needle.

mine did it too, found out the previous owner never put back in the little nylon spacer so it still isn't running perfect

it probably is a little lean on part throttle so raise the needle a notch to rich it up.

Removing the airbox cover and taping the hole didn't do anything for me either.

Ill give the needle thing a shot. I leave my chain fairly loose. Around 2 inches of play. Couple of people I ride with say the same thing, they think my chain is going to fall off. Are these ebay chains worth a crap? http://cgi.ebay.com/ebaymotors/00-07-SUZUKI-DR-Z400-DRZ400-DRZ-400-GOLD-O-RING-CHAIN_W0QQcmdZViewItemQQ_trkparmsZ72Q3a1234Q7c39Q3a1Q7c66Q3a3Q7c65Q3a12Q7c240Q3a1318QQ_trksidZp3286Q2ec0Q2em14QQhashZitem270278625629QQitemZ270278625629 They say they fit E and S, I have an SM, but I thought the SM's chain was also 520x112

If I recall the SM chain is two links shorter. Not sure about the ebay chain but usually you get what you pay for. When you get a new chain get a quality o-ring chain and steel sprockets.

Thanks guys. Should I try raising the needle two notches? or only one at a time?

Also, where is a good place to get a decent oring chain at a decent price? Thanks

Try one notch at a time.

Try the TT store for a chain. You'll get a fair deal, good service, and help support the forum.

jetting problem is solved guys. Thank you! I ended up needing to raise the needle two notches. made the low/mid rpms much smoother. And I'll look into getting a chain from TT. Thanks again!


Good deal. Thanks for the update.

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