Mikuni 42 MM carb

Hey all. I bought a 1991 FLHS last October for a rider/play bike. I've got the bike set up the way I want it, for ride, look, handling. When I bought the bike, it only came with an S&S Super E carb, the stock set up was long gone. The bike has little mods done, just an EV13 cam, the carb, and newer exhaust with Python Slip ons. I couldn't get the bike to idle down last fall, anything below 1100-1300 would start to lope until loading up and dying. Bike is running just a hair rich, but I thought the timing was possibly causing some of this issue. Choose to look at it last evening, check timing, ect, and readjust the carb. When I opened up the timing cover, I found that it had been moved to full advance. The hose running from the carb to the V.O.E.S. is old and hardened. Pulled the hose off the carb, and the engine slowed slightly, but not like I would have expected for the timing to have changed that much. I couldn't find the timing mark using the timing light, even after cleaning and painting the mark. I'm pretty sure the V.O.E.S. is bad, and plan to replace it by weekend. The S&s didn't have much for vacumn either, but maybe that's not uncommon.

Anyway, as this is a heavy bike, still a bagger, I was wondering about what will run best on the bike. Not worried about the fuel milage really, just want the best bang for the buck. I'm looking for suggestions here. I've run S&S with decent success on a 1996 Road King. I had a friend that was running a Mikuni 42 on a dresser, and it had a bit more to it, and got better milage too. Some have suggested modifying a CV, and running it. I don't have any of the stock parts, so I'd have to try to find someone that might sell the whole unit. Also I'll need to change the cable, I have mini apes on the bike now, and it's an S&S cable. What do you think would be the best route to go? I have a line on a Mikuni 42 kit, that has all but the Throttle cable for $300, new. Any suggestions much appreciated. Thanks.

Brent

I've had good luck with Mikunis. I remember about 15 years ago when I was hopping up an FXR I wasn't sure which carb to use. One of the guys who worked at the shop... an old school died in the wool fella told me that while he preferred S&S for himself, the Mikuni worked better. I had little trouble with the Mikuni. Later on I had a Twin Cam and tried the modified CV...I thought the Mikuni worked better and got better mileage. I'm no expert but that's my take.

Thanks for the input Sleepy. I've had decent luck with the S&S also, but had heard that the Mikuni was a better carb for both performance overall and gas mileage, at least on the heavy bikes. Just looking for some assurance before dropping the money for a different carb. Sometimes change is a good thing. Sometimes it's seems like I only dropped a wad of money to cause a different set of problems.

Thanks for the reply Chuck. The V.O.E.S. checked good, but the vacumn line to it was hard and of no use. New line on it, and the throttle cracked a bit and it works fine. Very little vacumn at idle with the S&S and the cam I have in this one. I got the timing set, and ready to dial in the carb. It already runs alot better. It was only in the low 50's and pouring the rain, so I opted to wait on a better day to adjust the carb in. I'm gonna play with this setup a little more, see what I can get out of it. Thanks for the replies, and if I can't get it straightened out, I'll be asking more later.

Carb options

I have a hopped up 80in evo w/mikuni and a Stocker with Slip-ons and SE filter kit with stock CV. When money gets a little better It will get a Mikuni also. Can never seem to get the CV carb right, the mikuni I go up alittle on the jets in the extreem cold, other than that once I got it dialed in I only have to adjust the idle setting once in a blue moon. The Mik 42 is the best for my money.

Thanks for the reply Butch, and welcome to the forums. Since I started this post, I've got the timing set, and the S&S carb dialed in. I'm sure it get better milage with a Mikuni setup, or a modified CV carb, but I'm very happy with the performance it has now. Bike pulls hard from 2k into redline, smooth and lots of grunt. I'm getting around 35-38 mpg now with it, and that's good enough for me. For the time being anyway, I'm sticking with my current setup. I may make changes next season, as I'm planning to build it up with 9.5 comp, different heads and cam next winter. Spent all the money for this year on it, unless something breaks. Just plan on doing alot of riding this summer, and make more changes next winter. Thanks to all for the replies.

MPG sounds about right with my MIK avg. If I really behave I can get about 42 to 45 mpg but I don't have that kind of discipline.

Good to hear you got everything under control.

Ride Safe & Ride Often

Thanks guys. Butch, I think I could get towards 45 mpg also, but I just ride this one for fun. I have an '04 Road Glide if I want the good milage and performance. It is a nice bike, but it seems so smooth, almost carlike in ways. Harley went away from the old mechanical feel, and have been doing so for years. I'm not saying this is a bad thing, but I really like the old 1991 better for my riding. It has personality, and a mechanical "alive" feel to it. It fits me better. Don't know how else to describe it......