CV carb jet recommendations?
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Joined: Jun 2007
Posts: 3,193
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From: North Atlanta Area, GA
I run a Hypercharger Pro (wide K&N element) and V&H duals/Big Ovals, and I run a 46 idle jet and a 185 main in my CV carb. Seems about right, but my bike is a heavy bagger. I can't say whether those jets would be right on a Softail - but since it's the same engine I would think they would with your intake and exhaust setup.
I've been told recently by a knowledgeable person on this forum that Keihin does not actually make a 46 idle jet, and the stock 42 idle jet then goes to a 45 then a 48. I have an aftermarket carb kit on my bike that I bought from harley-performance.com - and it came with 45 and 46 idle jets, and 180 and 185 main jets. I chose the 46/185 ones, and they seem to work fine... and my mixture is definitely not too rich.
I get over 40 MPG combined city/highway riding - maybe more... I have ridden over 160 miles on a tank without having to put it on reserve.
I've been told recently by a knowledgeable person on this forum that Keihin does not actually make a 46 idle jet, and the stock 42 idle jet then goes to a 45 then a 48. I have an aftermarket carb kit on my bike that I bought from harley-performance.com - and it came with 45 and 46 idle jets, and 180 and 185 main jets. I chose the 46/185 ones, and they seem to work fine... and my mixture is definitely not too rich.
I get over 40 MPG combined city/highway riding - maybe more... I have ridden over 160 miles on a tank without having to put it on reserve.
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Tourer
Joined: Feb 2008
Posts: 328
Likes: 13
From: Trabuco Canyon, California
I received the CV carb today and opened it up... I found 48/195 jets inside...so looks like I'll need to find some smaller jet sizes to work with since 195 sounds a little large for my setup
Outstanding HDF Member
Joined: Mar 2010
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From: Hallsville, Tx.
LOL, now you're talking!!
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Tourer
Joined: Feb 2008
Posts: 328
Likes: 13
From: Trabuco Canyon, California
Not a bad idea ...I'll can build a whole bike around those jets....good thing he didn't have a 205 in there...I'd really go broke...I think he was running a twinkie by the sound of the cam he had in it.
Since it has the sporty needle I think i am going to start with a 45 slow and 170 main as suggested by blkbagger...should run under $ten for a couple Yost jets.
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Joined: Oct 2007
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From: El Cajon Ca.
That's typical jet sizes for a 95" twin cam motor. It's what I run with a sporty needle.
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Tourer
Joined: Feb 2008
Posts: 328
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From: Trabuco Canyon, California
Finally I got finished with jetting this carb....I ended up with 42 pilot jet / 195 main jet.
I took the long route....I got the carb with 48/195 inside....I should have just tried it like that to start with....instead I dropped in 45/170 for a baseline...then tried 45/180, 42/185, and finally 42/195 today.
I took the long route....I got the carb with 48/195 inside....I should have just tried it like that to start with....instead I dropped in 45/170 for a baseline...then tried 45/180, 42/185, and finally 42/195 today.
HDF Community Team
Joined: Dec 2005
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From: NC USA
From my tinkering and results, I think you're going the wrong way with each jet. The main is only adjustable with different needles and that is very tiny changes thru the rpm range. But the low jet can be tuned with the mixture screw. With any similar cam/intake/muffler arrangement to what you have, 175 - 185 and 48 on the low jet works best for performance and economy and 185 is on the very rich limit of that. I'm willing to wager at higher speeds when you really twist on it, it'll fall on it's face... no offense, just my experience...
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Joined: Oct 2007
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From: El Cajon Ca.
I agree with the above. to rich on the main and to lean on the slow. I think I would go 45 slow and adjust the mixture to about 1 1/2 turns for a base. And a 195 main with a sporty needle will be real rich on top end. Go smaller on the main. 175-180 You need to retune your mixture with each jet change. and also take it out on the road for evaluation. Bike needs to be hot for all these.
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Tourer
Joined: Feb 2008
Posts: 328
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From: Trabuco Canyon, California
What both of you are saying is what I thought too....
But starting with the 45 jet I had to turn the A/F almost all the way in and it was still running rich. I started at 3 turns out. When I went to the 42 jet I started at 3 turns out and ended up at about 2 3/4 turns out for best running without being too rich.
For the main jet I started at 170 and the bike was extremely lazy at high revs in 4th and 5th but when I backed off the throttle the bike had a slight surge. When I went to the 180 jet there was a vast improvement, but still some surge as I backed off the throttle. At 185, a little more improvement...I didn't have a 190 so I just skipped to 195 and it feels really good when I go full throttle in 4th and 5th. I still need ride it more to see if it need ant fine tuning.
Is there any other tests you would suggest to confirm that I have the right jetting?
I am thinking there must be some other mods in this carb for it to perform like this but I don't know what would do that. I was told it had the sportster needle but I didn't confirm it. The needle is one that has the ez-adjust **** attached to it.
But starting with the 45 jet I had to turn the A/F almost all the way in and it was still running rich. I started at 3 turns out. When I went to the 42 jet I started at 3 turns out and ended up at about 2 3/4 turns out for best running without being too rich.
For the main jet I started at 170 and the bike was extremely lazy at high revs in 4th and 5th but when I backed off the throttle the bike had a slight surge. When I went to the 180 jet there was a vast improvement, but still some surge as I backed off the throttle. At 185, a little more improvement...I didn't have a 190 so I just skipped to 195 and it feels really good when I go full throttle in 4th and 5th. I still need ride it more to see if it need ant fine tuning.
Is there any other tests you would suggest to confirm that I have the right jetting?
I am thinking there must be some other mods in this carb for it to perform like this but I don't know what would do that. I was told it had the sportster needle but I didn't confirm it. The needle is one that has the ez-adjust **** attached to it.