should i try it?

ok so on this molkt carb on my gpx 150, blip the trottle and hold it, and it bogs till the engine dies. i have a 105 main jet and a 25 pilot jet needle 2nd notch from top. could the pilot be too rich. should i try the pilot that came in the carb or is it going to be too lean and cause damage. i have the mikuni on the way but sunday is a track day and i would love to ride.

Go to the Powroll website,Powroll.com. They have a great jetting guide that's really helped me with my drz 125 with engine mods.

what position are you holding the throttle at?

Is the bike warmed up, really warm, mine will bog if I whip the throttle and it's not. Are you bliping to WOT? I've heard that bouncing off the rev limiter can cause a bog? Did you follow P50's jetting guide? Do you know the 150 baseline for your weather/location etc.

not to wot, maybe half way. ive never hit the limiter before. i did follow oldschools guide. the bike was not really warm.

i would put the stock jets back in.make sure its good and hot then retry.some times dropping the clip on the needle a notch or two can help.

needle on lowest clip. then report back.

I tried all those things and even quickly opening the throttle to maybe 1/4 open would shut the engine off just like holding the kill switch. No pilot, main, needle or air screw position made it any better.

The thing is, I could very easily see the jetting changes. Going too far on the main made it blubbery, pilot jet changes could also be felt when it was too lean or rich, but in all setups I tried, the cut off with a quick throttle opening was still there.

I have done lots of jetting, but am by no means an expert, but I just don't know how to make that carb work (meaning my specific one, not MOLKT's in general). I see this problem posted often enough to think that maybe some of them simply have something mucked up inside. There is nothing visually wrong that I can find, but something has to be wrong on certain ones.

I tried all those things and even quickly opening the throttle to maybe 1/4 open would shut the engine off just like holding the kill switch. No pilot, main, needle or air screw position made it any better.

The thing is, I could very easily see the jetting changes. Going too far on the main made it blubbery, pilot jet changes could also be felt when it was too lean or rich, but in all setups I tried, the cut off with a quick throttle opening was still there.

I have done lots of jetting, but am by no means an expert, but I just don't know how to make that carb work (meaning my specific one, not MOLKT's in general). I see this problem posted often enough to think that maybe some of them simply have something mucked up inside. There is nothing visually wrong that I can find, but something has to be wrong on certain ones.

yes sometimes the quality control on these chinese carbs can be bad.somestimes the wrong jet is put into the batch and it screws things up for someone somewhere at sometime(and when you go to comfim your jetting there isn't any #'s on the jet:bonk:)also when whacking the throttle open really quick in netural its normal for any carberated bike to stall(especially if it has a pumper carb)when testing the bike it should be riden for a more acuate and relistic result

Ride it to warm it. Also have you checked your float level? If it's way off the engine could be starved for gas. Are you running the stock airfilter, I was... a china k&n style, oiled it... made any jetting attempts worthless until I got a UNI. (I don't know how good or bad your stocker is may or may not be an issue). Maybe try talking with someone who's jetted bikes in Florida for any tips. Temp and humitity effect what the engine is doing. Bump the ride it to test bit too.

my floats are good, using a uni air filter. everyone that i know at the track i ride at w/ this bike only (two people other than me) has ditched the MOLKT. i agree with chiro i have tried many adjustments and just can't get it right. i think (hope) it could just this carb? oh well i'll leave it be till the new carb gets here. i am going to send the molkt to oldschool for a parts carb maybe he can try it out and see if i am an idiot or not.

Carbs have a way of making us all feel like idiots at times. I found my "Mikuni" easy to work with once I got the basics down. At least you can order jets with ease. Did you try the needle position at it's leanest? Make one change at a time and ride to test? P50 recommened to me to keep a log of my settings... big help.

With mine, I changed out the molkt and put a mikuni in and the problems disappeared. Even riding, if you tried to loft the front wheel over an obstacle, it would fall on it's face. I was not whacking the throttle wide open, but just blipping it like one normally does to wheelie or clear the front wheel would not happen.

I can relate with you about the molkt I also had problems with mine:banghead: I installed a 22mm mikuni and got it to run spot on right off the bat but I lost to much power with the 22mm .I just kept pulling off the Molkt and playing with the floats and trying different needle settings .I finaly got mine to work fairly decent .I ended up with the stock main jet ,25 pilot,needle clip at the very top "leanest" position.Now dont ask me what the float hieght ended up at:excuseme: I just know the carb works fairly decent now but it drove me crazy there for a while

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now