mikuni carb on my 1950 flathead - Harley Forum

1950flatty · #1 11-13-2008, 05:40 PM

need some help here... bike does'nt seem to run smoothly. hesitates a bit from 1/4 throttle up. anyone know what jets i should be running? i plan on checking the timing as well... thanks

Buzz Kanter · #2 11-13-2008, 09:52 PM

Quote:

Originally Posted by 1950flatty

need some help here... bike does'nt seem to run smoothly. hesitates a bit from 1/4 throttle up. anyone know what jets i should be running? i plan on checking the timing as well... thanks

Mikuni is an amazing carb ONCE it is properly and completely dialed in. When I bought my knucklehead it had a Mikuni and ran strong. When I rebuilt the engine I went back to a Linkert though.

Good luck and you might try posting this question at our classic American Iron forum at www.caimag.com. A lot of smart, tech savvy folks over there for the old iron.

mac1221 · #3 01-22-2009, 08:00 AM

What size venturi are you running, cams , how far advanced is your timing, have you done the simple air leak tests.
mail me at hummer9@cox.net -- we'll find out what the problem is .
Mac

unclepsycho · #4 01-22-2009, 09:27 PM

If ya post your notes back and forth here, then we all get to benefit from the info. I was kinda curious as to what the solution might be. I have a mikuni on my bike as well and it seems to run fine right now, but if it ever gave me fit's I could refer back here in the future.

Thanks and good luck

frisco-rigid · #5 01-23-2009, 01:59 AM

Hey Unc

Kinda strange why a guy would want to answer questions privately by email huh.. This is the second time he's done it..
On that other question/post he evidently didn't read the all the posts cuz he didn't know that the question/prob had been solved when he offered to "trouble shoot" by e mail..
I only did it once cuz some guy requested it.. I dunno why he did that..

I see that this guy has a shop, so, that might be the reason, self interest..

Another reason could be that he Knows-Nothing and doesn't want to embarrass himself Or,, maybe he's been reading alota our threads/posts and doesn't wanna get caught plagerizing..
Not saying it's so but it does raise suspicion..

Anyway Unc-- there's a couple of us that run Miks,, all I run,, so you got buds here if you have a question..

unclepsycho · #6 01-23-2009, 10:28 PM

Frisco, and flatty

Mikuni's are great. For a while there I had gas pouring out of the vent hose right after I started. I would shut the gas off and ride it for a while, then turn it back on and off till it quit overflowing or I got home.( too stubborn to put it on a trailer to get 'er home) I tore into it.... then it did it again a few days later, tore into it again . Long story short.... I didnt have a vented gas cap!!! and it was summer time at 100*+ out there so when I turned on the gas, the pressure in the tank from the heat would pump the bowl full till it overflowed. then it would just force the fuel out until it could equalized the pressure. so the carb was actually fine. I may have messed up the carb for the long term but it runs fine now. I got a vented cap now.

As far as flatty's original situation, it may be the timing, that makes it hesitate? he says he will check that too so maybe thats it. I havent had the time to look up jetting for that engine with the mikuni. maybe tomorrow.

good luck

frisco-rigid · #7 01-24-2009, 02:16 AM

Hey Unc

The wierd thing is that Flatty asked the same question on the same day in the Carb section..
He apparently never checked back cuz he's been asked to say which Mik he's runnin and well, he has not said..
Cannot give him any advice if he won't state what size Mik or check back at all..

Ooh well.........