Jetting question

musselman

musselman

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Jetting question, PI Pipes

I just installed a set of power inc. triple pipes on my 99 sx700 and i just have a question about jetting. The PTO side plug is black in colour so that seems safe. The other two plugs are tan in colour and they have a small amount of white on the electrode tip. This worries me a little bit because i don't want to melt down those pistons. I have just been riding it around the yard so it's mainly zero to half throttle. It seems like it might be idling slightly lean though, however there is no bog off idle.
This is what i'm running for jetting:
Main: 147.5 PTO, 148.8 Center & mag
Pilots: 47.5
Fuel screws: 2 turns out
Needles raised one notch
I would like to be on the safe side for jetting and i'm not sure what i need to change.
Any help would be appreciated.
 
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You should be close with that jetting. The only way to be sure is good plug color and wash for 1/2 and full throttle.
It sounds like you could go to 50 pilots if you're 2 turns out and lean.
 
Are these center or end dumps?
My center dumps have been a pain in the a$$ to dial in.
I have the same set up as you with 50 pilots and 2 turns and it still is on the lean side at idle. At full and half it's a little too rich and I'll be putting the needles back to stock position.
 
i would up the pilots to 50 @ 1 1/2 turns out and do a plug check. you really need to run down the trail to check the mains.
 
I'm not sure what the difference is between center and end dumps. Mine are the same as the ones in the tech section PI pipe installation. I rode this weekend in temps from 0 celcuis to -25 C. It was a little rich on the warm day but it was still ok when it was -25. It seems like there is a lean spot right at trail cruising speed though. Just about 5 to 6000 rpm. Did a half throttle plug test and they were all tan coloured with a tiny amount of white on the electrode tip.
Would i be safe dropping the needles back down to stock? I was trying to cure that lean spot but it didn't work.
 
You need 50 pilots and I had to run my needles up 1.5 to get the mid range lean out. You will burn it down coming back down off the mains instead of getting up to them. those pipes get nasty lean on theway back down. Maxdlx
 
maxdlx said:
You need 50 pilots and I had to run my needles up 1.5 to get the mid range lean out. You will burn it down coming back down off the mains instead of getting up to them. those pipes get nasty lean on theway back down. Maxdlx
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So what clip position is that on the needles and how many washers under
 
Those pipes run just fine. I can't remember what stock needle setting are on those motors. If it is in 3 with one on top and one on bottom drop it one clip with one on top one on bottom. I have a set of 50 pilots$20 shipped to you. Maxdlx
 
maxdlx said:
Those pipes run just fine. I can't remember what stock needle setting are on those motors. If it is in 3 with one on top and one on bottom drop it one clip with one on top one on bottom. I have a set of 50 pilots$20 shipped to you. Maxdlx
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I think my needles were stock and they were #3 with one on the bottom and one on top and i just raised them one clip position.
$20 shipped to canada? If so i'll take them.
 
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