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Discussion Starter · #1 ·
I installed some Specialty Spares on my 06 Thrux recently. The AI was removed by the dealer before the bike had 1 mile on it. My question is... do I need to rejet or adjust the carbs at all? It seems to run as usual, but with a bit more torque and a lot more sound. I'm just afraid (after reading some posts) that I may be running too lean. OH... it does pop when decelerating... but I didn't think that was a big deal...is it?

Thanks....
 

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it's running lean. You need to re-jet. Pat's jetting calculator says to go to a 125, but i think that may be to much. I imagine a 120 would be better, but i really don't know. Anyone else running these?
TJ
 

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i have that manual and it's ok, I think that you should still re-jet. If it's popping on deceleration that is a definate sign of running lean. i would drop the nice folks at Newbonneville an email and see what they say.
TJ
 

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I had the specialty spares TT's on my thrux and was running a 130 main at sea level. It popped a lot too, but I think that has to do with not having any back pressure whatsoever from those pipes.

The sound of those TT's will definitly get attention...

I replaced them with D&D's and kept the jetting the same( per the calculator) and no more popping.

Cheers!
Josh
 

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Discussion Starter · #7 ·
Thanks guys...
This is what Dale from S.S. said... "Check with your dealer to see if they changed the pilot jets, if not go up to #45 pilots and open up the air screws to elimanate the popping."

So I guess there are a few solutions.
 

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If you have just the mufflers, 42 pilots at about 2.5 turns and 118-120 mains should be close. Probably ok with prod pilots and 3.5 turns. I would try just opening the prod pilots first. Also make sure you have no air leaks where the muffler attaches to the pipes. Good Luck-T1
 

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With the TT's you basically have a header with a baffle right? So the only leak would be at the cylinder to header connection, you should check that.

I wonder if the pipe itself does not provide enough back pressure, that is what scootapimp is saying right?

I think you would do well to get the folks at Specialty Spares on the phone.

One other option is to ask the guy a Bella Corse, offer to buy the jets etc.... from him also ask him what if he go the same results.
 

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With the TT's you basically have a header with a baffle right? So the only leak would be at the cylinder to header connection, you should check that.

I wonder if the pipe itself does not provide enough back pressure, that is what scootapimp is saying right?

I think you would do well to get the folks at Specialty Spares on the phone.

One other option is to ask the guy a Bella Corse, offer to buy the jets etc.... from him also ask him what if he go the same results. I know he recently built a bike with the same pipes.
 

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I am wondering if you guys settled on the best main jets for Specialty Spares TT pipes which I now have on order. My Thruxton currently has 117.5 fitted for a previous set of pipes. Have now just removed snorkel and added unifilter. I have a pair of 122.5 and 130 lying around I can use.
 

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AI removed, Uni filter, stock mains, 42 pilots, 3 turns out.

If you have NARKed it, then you would have to go up on the mains.
 

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You need to get it on a dyno with a sniffer thats the only way you will be sure where you are.Alot of open pipes pop some when you let off .Its not allways a bad thing.One way you can get a ball park idea is run bike wide open in high gear for about 4 seconds then let off gas to about 7/8 wide open if bike feels like it picks up when you let off to 7/8 you are to lean. If it dosnt then try the next smaller main jet and repeat till you find where to lean is then go up one size.Dont let off the gas to much just alittle so you keep on the main jet only.0-1/4 throttle is afected by pilot and air mix screw .1/4 to around 3/4 is the how high you got the niddle( can add shims)
 

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You need to get it on a dyno with a sniffer thats the only way you will be sure where you are.
I wouldn't recommend spending the cash for multiple dyno runs for a no-brainer like this. Specialty Spares has already spent the cash on the dyno runs so why should we re-invent the wheel? I have their TT pipes and listed my setup in a previous post (which I got from SS).

Just call Specialty Spares, tell them your setup and they will tell you what jets you need. A 2 minute long distance call from HK to the USA will be a heck of a lot cheaper than multiple dyno runs to get the same answer they will give you. Or better yet, email them for free.
 

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Hey Duckman, you list your set up same as mine i.e. AI removed, Uni filter, and you use STOCK MAINS. When I enquired with SS previously re using 130 main jets (as per Jenks guide) he said that should do. So thats how I got confused between stock and 130 and everything in between!
 

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Hey Duckman, you list your set up same as mine i.e. AI removed, Uni filter, and you use STOCK MAINS. When I enquired with SS previously re using 130 main jets (as per Jenks guide) he said that should do. So thats how I got confused between stock and 130 and everything in between!
The 130's will work but you will be dumping a lot of unused gas unless you twist your idle mixture screws in a little. I opened mine up from the stock condition, effectively changing the mains to about 117.5 or 120 without touching the idle mixture screws. The pilots are used thru the low rpms which is where you will notice the popping from the lean condition when you let off the throttle. Mine didn't pop when I let off at full throttle, just when I got down to low RPMs.

Since your setup is similar to mine, you can judge by my MPG if you are using too much gas and can twist your screws accordingly. I get 37 - 38 miles per US gallon at 80 MPH w/ no head wind and I weigh about 210.
 

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duck man that one size fits all is not allways true with our bikes.bikes alone are not the same .weather and elevation are not the same where everyone lives and rides.The give you what works most of the time for them .There can be as much as 1 to 5 hp in haveing a bike tunned right.
 

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duck man that one size fits all is not allways true with our bikes.bikes alone are not the same .weather and elevation are not the same where everyone lives and rides.The give you what works most of the time for them .There can be as much as 1 to 5 hp in haveing a bike tunned right.
Yes, but is it worth multiple dyno runs for that little gain on a street bike? If I was racing, I could see the benefit but my street racing days are over. I'm old enough now I know I can die, and my bones aren't as elastic as they once were. I feel my money can be spent in better places than to help send a shop owner's kid to college for a couple of extra HP.
 

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You got the TTs ? Cool .

I know a guy running the tts on his Bonnie . I think he said SS gives you jets with the kit (?) . He was running 125 / 42 with Airbox , K&N w/o snokel.
LOUD !
 
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