dm440c

bought the bike in my sig with all the mods described from forum member Kcar last December. Have put about 150 miles on it so far and it runs great except when holding a steady cruise RPM, especially around 4000 or so. Basically if you are putting along a country highway holding steady RPM in 3rd or 4th gear it has a noticeable lean surge. If you cruise closer to 5000 it seems happier.

So far I did a visual check for vacuum leaks, hoses or ports open, that sort of thing. Haven't dug any deeper yet. Figured before I start taking things apart I would check with you guys to see if there is a common tweak or failure related to this that I should know about.

aja

I get it but around 2500, I'm pretty sure a carbs sync will fix it. That and adjusting the leanness.

dm440c

10-4, he told me he had done a carb sync on it recently before I bought it and he had installed some vacuum hose extensions to assist this process. I checked and yes they are plugged off at the ends so no leak there, but I suppose I could double check the sync to see if it is where it needs to be.

thetophatflash

You are probably running lean in that 4500rpm range.

Wicky

Cans? Airfilter? Has it been rejetted/dyno tuned for the slip-ons

aja

Ya if its been jetted that could be your problem also

dm440c

he claimed it was but hey, who knows. Feels like it's leaning out to me but I suppose the right thing to do is put a sniffer in the tailpipe and see what we read for the A/F ratio. I just thought I'd post here first to see if there is a common issue with a no-brainer fix related to these models.

thanks for the replies guys

KCar

As you can tell I am missing the bike, because I am still looking at this forum from time to time. Sorry to hear about that lean issue. You may want to check those caps on the lines to see that no air is leaking by. Maybe change them or clamp them. I would also check the carbs snyc, just to make sure. I did do one, but you never know. The carbs are not jetted, just has shims under the needles. I found the how to do here. Two in the back carb and one in the front. Maybe jetting, but I really didnt notice any lean issue...it could be the cooler temps of this time of season it is more noticeable..but I am just reaching. Good luck and if have any questions don't hesitate to ask.

On another note. I rebuilt my truck engine and is working great now... thanks to you.