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Discussion Starter · #1 ·
Are any of you running one of these in a stock (albeit drilled slide) CV carb? I'm thinking of putting one in my carb to help "perk" up my FXD.
What I want to know is if they only use more gas like a Dynojet kit, or do they really make some kind of noticible difference? I did the St 1 mods and I'm debating on head work too. I just figured the the YPT is cheaper, I can get it and install it myself. Head work requires a good shop and downtime. :mad:
 

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The Dynojet kit causes poor gas mileage only if installed improperly. The placement of the needle retainer and clip is imperative and the directions for this procedure are somewhat vague. A call to the tech support line, which by the way is excellent, is all it took to set things straight.

The Thunderslide/jet kit in mine performs flawlessly!

Similar results can be had by using Keihin jets of the appropriate size, a Sportster needle and a slide spring for a Keihin CV 44 and idle mixture screw adj. Do not drill the slide! Just radius the leading edge with a Dremel followed by polishing. Don't touch the ears of the slide with the Dremel or binding may occur.
 

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i dont know if it was the thunderslide kit or the rejetting of my carb, but it made a whopper of a difference. the thunderslide seems to work well.
 

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One note: If I was to pick up another CV, I would opt for the Sportster needle, CV 44 spring, radius & polish the slide and carb throat and rejet sans the Thunderslide. No slide flutter with these mods and about one fourth the cost.

The Thunderslide works well but the above mods will yield almost identical results. No seat of the pants difference!
 

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supersport said:
Don't touch the ears of the slide with the Dremel or binding may occur. [/B]

Have you notice that only the outer most 1/2 of the ears slide in the runners? The inner 1/2 next to the inside can be dremel a grove to help make the slide lighter. A grove running the lenth of the cyc. Then hone the inside to get alot more off. The most Ive got (with out any damage to the slide ) is .6 oz.
 

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I RAN THE YOST POWER TUBE IN MY OLD 91 FLHS. IT DID MAKE A NOTICABLE DIFF IN THE MIDRANGE AREA. IT ALSO COMES WITH A NEEDLE THAT CAN BE ADJUSTED (MUCH LIKE A MIKUNI NEEDLE) DUE TO THE FACT IT HAS MULTIPLE GROOVES ON THE DIAMETER. GOOD BANG FOR THE BUCK, BUT YOU STILL NEEED TO SPEND THE TIME TO DIAL IT IN.
 

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I've got 3 CV carbs in my shop. One with a Thunderslide kit, one with a Dynajet kit and one with stock jets and spring, sporty needle and adjusted mixture screw. I've got 61K on the bike now and have run all three of them quite a few miles. I like the one with the sporty needle as good as or better than the other two. Sometimes simple is more than adequate.
 

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Habanero Kid

I have a 2002 FXD with a YPT. I noticed a performance increase right away but my gas mileage has dropped to around 30 m.p.g. in the city. I am also running V&H Longshots, which I have been told by Bob Yost require more fuel than most exhuast pipes. Therefore, he recommended installing the red needle instead of the blue needle. It runs great. There are no backfires, pops, etc.
 

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Discussion Starter · #9 ·
Yep, the more I think about it, the more I want to do it. This is a winter project. Thanks for the replies. Plus when I do the 95" and the heads the YPT will work with them as well.
 

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Habanero Kid

Just wanted to let you know I am getting a local shop here to pull out my YPT this weekend. I am just going to get a tuner's kit put in. Nobody here recommends a YPT. I should get back some gas mileage to. I will let you know how it goes.
 
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