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Discussion Starter · #1 ·
Today I went for a ride. Bike is '01 FLHTC, 95 in, stock heads, Andrews 26g cam, Wild Pig mufflers. Carb is cv 40, 48 idle, 195 main. Runs great (since I plugged the vacuum hole). It seems that bike is not getting good gas mileage. Is the 48 too rich? Should I drop to a 46? Also how many turns out on the a/f screw? I am paranoid of running too lean. Thanks.
 

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I'm surprised it doesn't sneeze and pop with the 195. I had that in my '03 EGC, 98" S&S 510 cams and GMR worked stock heads. I had to lean it out to a 185 main. I am also running a 48 intermediate, with the A/F screw about 1 1/2 to 1 3/4 out.
 

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What needle do you have? Dynojet kit? 48 slow jet is too rich on mine, 95", stock heads, 203 cams, Pro Pipe. With the 48, I got best idle at 1/2 turn out on the mixture screw. Tried a 46 and got best idle at 2 turns. Not really much difference between 46 and stock 45, 0.01mm or 0.0004". I ended up going back to the 45 and about 2 1/4 turns out. If you're too lean on the slow jet, you'll get coughing from the carburetor when you give it throttle. 195 main with an 88 Sporty needle works good for me. I tried a 185 main and it didn't work at all, ran terrible when giving it any throttle. 190 main works good but the 195 is a little better at WOT. I get 47-50 mpg, Dyna with a windshield.
 

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Geezer, I just noticed your "no clutch slippage" remark. I put the reduced effort kit in mine a month or so ago and mine doesn't slip either, although your motor is no doubt a lot stronger than mine. I fully expected the clutch to slip after reading all the comments posted about the spring being only for stock motors. Apparently the posts were from armchair quarterbacks that haven't actually tried it.
 

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fastbagger said:
I am surprised that you use a 185 main because the stock cv 40 comes with a 190. How is your mileage???
Mileage isn't too bad, but it's been really cold here. Thats probably why she's running better on the 185. Also, the DJ needle runs them kinda fat too. A dyno with A/F readings will tell the story.
 

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murphdog said:
Geezer, I just noticed your "no clutch slippage" remark. I put the reduced effort kit in mine a month or so ago and mine doesn't slip either, although your motor is no doubt a lot stronger than mine. I fully expected the clutch to slip after reading all the comments posted about the spring being only for stock motors. Apparently the posts were from armchair quarterbacks that haven't actually tried it.
Yea Murph, so far I have no problems with the clutch. It hooks up just fine. I've got about 4000 or so miles on the reduced effort setup, and thats with a 95", cams, exhaust and SE heads. Now with the 98" setup I have a TON more torque and guess what? NO SLIP!! There's 30K on my bike as of yesterday. As long as you keep your clutch properly adjusted it should last a long time.
 

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fastbagger said:
I am surprised that you use a 185 main because the stock cv 40 comes with a 190. How is your mileage???
If he's got the DJ kit in there, the emulsion tube is different than stock one, so a smaller main jet is used.
 

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Fastbagger, let us know what you come up with. First thing I would do is replace the 48 with a 45 and adjust the idle mixture. What mpg are you getting, you never did say?
 

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Discussion Starter · #11 ·
Murph just got back from a ride after rejetting. I rejetted to a 46 and played with the a/f screw. Did not ride as good as the 48. I put the 48 back in and turned down the a/f screw from 2 turns to 1 1/2. Seems to be getting better fuel mileage. I will be able to tell when I go for a long ride. With the 48 and 2 turns on a/f screw I was getting about 160 miles to a tank (32 mpg). I will see if it makes a difference. If I cannot get a good tune I will bring to dealer for Dyno.
 

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Ed Y said:
If he's got the DJ kit in there, the emulsion tube is different than stock one, so a smaller main jet is used.
Yea Ed, I have the DJ tube, needle and jet installed. 33 degrees this AM on the way into work. 36 miles each way and nary a sneeze snort or pop. Pleanty of throttle response too. Sometimes too much "throttle response" (if there ever can be such a thing) for my own good. Or gas mileage! Or rear tire mileage!!
 

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You're mileage is more dependant on the needle diameter and height. I've also heard that the Yost tubes can cause problems too.
 

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Duoglide_62 said:
You're mileage is more dependant on the needle diameter and height. I've also heard that the Yost tubes can cause problems too.
I kinda was wondering about the Yost tube, too. I've never had one, so can't comment. It wouldn't be too much trouble to replace it with the stock tube and see what happens. The Sporty needle and Yost tube may be a bad combination.
 

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Try this to set your mixture screw. Fully warm up the motor. At idle start turning the srew in untill the engine stumbles. Then turn out until the idle smooths out then open onther quarter turn. Increase the idle if needed. IF you can close the screw alll the way without the engine starting to stumble then the idle jet is to large. Replace with a smaller jet and repeat. Changing the idel jet will have some effect on mid-throtle as well so if you go one jet size smaller and notice lean mid-throtle response raise needle with clip or washer. Good luck.
 

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I'm totally confused (wouldn't be the first time) about exactly what's in the carb. If it's Yost tube, then it's not a DJ kit. I'm not familiar with a Yost setup either but I agree with Murphdog, using a sporty needle with either a Yost setup or a DJ kit would probably be a bitch to tune. Use of the sporty needle has always been recommended for use with the stock CV emulsion tube. JMHO

I'd bet that's where your mileage is going and I'd also bet that carbon buildup is commencing on the piston tops cause you're running fairly rich.
 

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Discussion Starter · #17 ·
I took the yost tube out and replaced with stock emusifier. My friend said that you have to use the needle supplied with the yost kit. I experimented. Oh well, at least I know what the problem is. Now I have to fine tune it. Thanks for everyones info......:thumbsup:
 
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