I just got an 06' RK custom that has 2000 miles on it and is bone stock. I put some V&H ovals and stage one breather. The "tuner guy" at the local HD dealer told me to put in a 175 main and a 45 slow jet. The parts main at another dealer told me to put the SE kit in it. I took the carb apart and it came stock with a 190 and 45. I put in a 200 and left the 45 in it and turned the idle mixture out 3 turns. The bike runs good but seems a little fat. Can anybody give me some input as this is my first HD carb to work on? Thanks, T.

 

put the 190 back in or a 185 before you screw up your engine by running it too rich......
if your oil smells like gas... you're too rich. and that gas cuts the lubricity of the oil.... rich running is causes alot of problems that are not immediately noticeable, excessive carbon build-up, accelerated bearing wear, yada, yada, yada....

with just an a/c and pipes, all you need to do is give it about 1 1/2 to 2 1/2 on the mix screw from GENTLY seated, or wherever you get the best/smoothest idle when it's hot, and *maybe* a 46 slow jet or N65C or NOKK needle, but I doubt it. been there done that, and have had it confirmed with an afr test on the dyno. a 175 sounds kinda lean, a 200 is wwwwwaaaaaayyyyyyyy to fat on a stock 88" motor. do a WFO pass, then go to a 190 and do a WFO pass... if it feels quicker, then do the same with a 185 and see how it feels.

do not install a SE or DynoJet or any other kit, do not drill the slide, do not shorten the slide spring.

the parts guy just wants to sell parts.
there are more SE/DJ kits that have been yanked out laying on the bench than there are still installed.

example;
my '06 RK has a 95" kit, cams, ported heads, a/c, pipes, etc., I have a 190 main, 46 slow N65B needle and 2 1/4 turns on the mix screw, and it is at 13.2 ish to 13.6 WFO, 13.7 to 13.9 at cruise, which is slightly rich for cruise afr... made 95.8 hp 99.9 tq.... I'm pretty sure your 88" don't need more fuel than mine....

 

Thanks for the input. I still can't figure out why that thing had a 190 jet in it. It apparantly came from the factory with it. T.

 

can't figure out why it had a 190 main???? it did come from the factory with it....... what's there to figure out???

 

I can't figure it out because the tuner guy at HD told me to go with a 175 which would make it leaner. I thought when you put a stage one breather on and different exhaust you lean them out so you need to go richer so that is why I put in the 200. I am confused. I am getting ready to put the 190 back in this morning so any input this morning would be appreciated. Thanks, T.

 

changing a/c & mufflers leans them out *slightly*, it ain't very much.
the main jet affects mainly WFO, it has some influence on light load part throttle cruise, but not much, that's where the slow jet, needle and idle mix screw have the most influence, and where most people do 95% of thier riding.

depending on your altitude, a 175 may be the right main jet... there's no real way to know for sure without an afr meter reading, which means spending $$ on a dyno tune.

I just know, for a fact, without a doubt that a 190 is what your bike came with stock, unless it was a California bike, which then had a 185 main. and that a 190 will not be too lean for your bike and burn it up just because you changed the a/c & pipes.
contrary to popular belief, especially on these internet forums, a 190 on a totally stock bike is already rich @ WFO, with a/c & pipe change, it should be just about right... but again, the only way for you to confirm that is with a afr check.
How does it run? backfires? coughing out the carb? jerky and bucking @ slow speeds?
then it may need a bigger slow jet... or the needle shimmed up a bit.... or both, it's all on how the motor responds to a change.
how did it run before the a/c & pipes?
I could write a book about it... I have been through all the carb stuff, DJ kits, needles, drilling slides & air bleeds, everything... and I always end up with the best driveability and mileage with the carb very close to it's stock configuration.

 

The problem is that the bike was sitting up and the slow jet must of had some shelac in because it was running like crap sometimes before. After putting in the new slider and spring and changing out the jets it runs much better. I put the 190 back in it the morning and took it out for a ride. Seems to run OK however the mixture screw doesn't seem to have much effect on the idle speed. Right now it is out 2 1/2 turns. Sometimes at idle it has a little flat spot when tweeking the throttle. If you blip the throttle it will backfire and die but normal acceleration seems fine. Maybe a washer or 2 under the clip or move the clip down a notch?

By the way my daughter says they are forecasting a blizzard in Manhatten today. It might get up to 80 here but down in the thirties tonight and tomorrow night.

Thanks again, T.

 

I agree 185 or at the most 190 main 45 slow and a .030 shim under the stock needle. Make sure you have no carb seal leaks. If you turn the air fuel screw all the way in it should stumble and probably die. Generally 1.5 to 2.5 turns out from lightly seated are in the ball park. Bike has to be fully up to operating temp to correctly set the air fuel screw.

 

yeah, we are in a freakin' blizzard warning.....supposed to get 8-14" of blowing, drifting snow... this sucks!
If the needle has grooves and a clip, that could be part of your problems, Keihin (stock) needles do not have clips. somebody has been in there mucking around...
I agree with mtclassic, and I will add that if you have a 45 slow jet in there, and it don't stumble badly or die, it could be the air bleed jets in the throat are plugged up or something else is not right.
sounds like to me that carb needs a good, thorough cleaning....

a lot of guys find that a 27094-88 (N65C) '88 Sportster needle with no shims works really well. the straight section is a bit smaller allowing a slightly richer mixture.
make sure the float level is correct, and *all* other parts in the carb are stock and good condition. I also have had good results with a NOKK needle, I don't recall the part #.

Here's a quick test that will tell you if you have to fat of a jet in the top end....
Run the bike through the gears into third gear and run third up to 60-70 MPH full throttle, then chop the throttle about 1/8 to 1/4 back and see if the bike either surges ahead or stumbles then recovers.

If it surges ahead, your jetting is lean
If it stumbles and recovers , your jetting is rich
If it makes no difference, you're pretty close.

Quick and easy, pretty accurate too.

 

Well I found the main problem. I have been experimenting with different things on my carb. My buddy who used to build custom carbs assured me that I needed a smaller slow jet. I told him there was no way i needed to go smaller than a 45. He said that is the only way I could be running that rich on the slow circuit. I took it apart today and pulled out the slow jet and was going to put in a 44. I found that the knucklehead at the Harley shop sold me a 48 instead of the 45 i asked for. I put in the original 45 and the bike runs leaner, just about right. Thanks for the input. T.