smoking at steady hwy speeds?

[rd400canuck]

Hey guys,

I notice when im on the hwy at steady speed and not speeding... there is smoke coming out of my bike. I really notice it at night because the clear underside of the brake light illuminates it. If I open the throttle more to accelerate it increases the more i open it. I am running around 40:1

I know my bike is rich because I only run the air screw at 1/4 out because it really prevents the closed throttle bucking and surging. The needle is on the middle clip and I have 150 mains.

What ya think? Am I way too rich? The bike runs smooth and its not fouling plugs, yet, but... could it be running much better?

Thanks again,

John

[m in sc]

is it on the pump or premix? mine are clean, all of them, either premix or pump at steady hwy speeds. smokiest is the t500, but thats just nature of the beast i think.

maybe go up on the pilot size and bring out the air screw a bit. id imagine you are at 1/2-34 throttle at steady speed so main not really a factor. 

[rd400canuck]

I'm on premix currently.

I'm certain I am not passed 1/4 on the hwy. I had tape on it one time when i was jetting and I was between 1/8 and 1/4 never more.

I'll try the bigger pilot.. I have 27.5 in there now. Stock is 25 i think.

john

[forexer]

since your asking for opinions here's mine -  If its running smooth and not surging or fouling plugs i'd leave it as is unless it's smoking profusely. Maybe have a friend ride the bike and you follow him from behind and see how bad the smoke really is.

perhaps it's not smoking as bad as you think it is - also it might be because of cheap oil make sure your running a good oil like
Klotz tc-w2


anyways just my 2   Good Luck!

[Jspooner]

^^^^^agreed, use good oil for sure, make sure the pump is adjusted right, also make sure the pipes are clean.

[Seizer]

Could it be oil pooled in the pipes?

[iranana]

depends a lot on the oil (I find mineral smokes a lot more than some of the synths) and how you usually ride the bike. My little 250 that i ride mostly around town smokes quite a bit for the first couple of mins when it gets out onto the highways, needs a good thrashing to clear it out from time to time

[rd400canuck]

I looed yesterday on the hwy at a steady 5500 rpm and I didnt really see it... then i opened it up and I cold start to see it.

I think its the white LED light at night making it look like there is more than there is and playing on my mind.

However... the bike is defo rich... the ends of my stock exhausts are covered black. I think I'm gonna lean out the main a little because it seems to lean the needle out as well...  160's made it burble a little... 150's stopped the burbling so I left it there.... I'm going to put some 140's in it to clean it up a bit. It should stop the small levels hesitation I feel between 4 and 5000 rpm because its too rich.

[m in sc]

do the needle first.