[AllMightyThor]

Hey i'm from maine and new to this forum i just sold my 1999 blaster an 400 bucks for an 03 preddy i love it so far and i've put a k&n drop in filter and a fmf power core 4 slip on i havent rejetted yet only a couple rides but it goes mint plenty of power i wanna know do i need to rejet? And to what size ? I don't wanta burn it up so what should i do? Any help please

 

[Bruce!]

Welcome to the board!feif:

 

[AllMightyThor]

well, thanx. no info though?

 

[blueline15]

depends on a ton of variables. contact FMF and ask what they recommend for jetting. they should know. then take into account that the K&N flows more air, so you may need to go up one more size, you may not, just depends

 

[Nate782005]

A little rich is better than a little lean. You need to rejet. I ride a similar Pred and use a mikuni (not dynojet) 165 main, 45 pilot, 2 3/4 af and 2nd from the top slot on the needle jet. Assuming your not at a high altitude.

 

[69z28fan]

How about Dial-a-jet? I put one on mine and I live at 5000'. Works pretty cool. At higher elevations, just turn it 1 click to lean out the mixture, opposite if you're at sea level. Beats tearing apart the carb each time. So far, so good and less than $100.

 

[redneck2725]

I have a Yoshi pipe and a aluminum airbox w/ a K&N. I just jetted to a 170 Main, 3 turn on the A/F screw, and 2 groove from the top. My Pred is running 100% perfect, zero hesitation and no backfiring or other issues.

 

[Thor]

Welcome! Cool name BTW! :arco:

 

[gmb357]

?air fuel screw pred 500 04

Which screw is this a/f screw,,Im looking at the diagram on bikebandit but its vague just saying screw...

Thanks 727

 

[Diesel432]

I have a problem I just put a hmf full exhaust rejetted put in a 165 and needle jet on 2nd slot cfm airbox with 2 k&n air filters bug my predator is really sluggish what does that mean?

 

[gmb357]

Did ya cut a few coils outta the needle spring so its less fiem so the diaphram can react more quickly for better throttle responce?

 

[Diesel432]

No I didn't you think that will help. I also adjusted the a/f screw 3 turns open

 

[ridemhard]

Did you say 2 K&N filters? that can be your problem right there. Aslo i would look into a 150 jet, sounds like it running rich

 

[Diesel432]

Yeah 2 kn air filters Thats what the cfm air box I have uses. Idk it had a 155 with all the stock parts on it and it ran great that's why I figured I needed to go up.

 

[EricOnAPredator500]

We both have 2007 Preds, so I was wondering, when you said you used a 170 main jet, is that a Mikuni or Dynojet? And do you have the stock Mikuni needle or a Dynojet needle? I'm using a clamp-on filter straight to the carb and a full Yoshi exhaust. I'm using a 170 Dynojet and it works best so far! I put in a 147.5 pilot, but I haven't moved the pilot screw from it's stock 2.5 turn position yet. I did drill out the plug though. My needle is the stock one and I put it one richer on the 4th notch (raising the needle). Seems to run good. I tried bigger Mikuni jets and the results sucked ass! A Mikuni 167.5 and 165 were too big for my setup. I also tried the richest position on the needle and it was no good.

 

[ETV13]

I'm on a 07 also, HMF pipe, cfm airbox at sea level. I went with dynojets, 175 main, stock pilot. If you're struggling at midrange adjust the clip on the needle to the 3rd or 4th notch rather than the mainjet. If you're going to use a dyno main jet use the dyno needle with it.

 

[Cavemancade]

I have a 06 preditor with a full yoshi exhaust and stock air filter
It has a 158 main and a 58 pilot with the pilot screw 2 turns what should I adjust it to

 

[latebird]

The pilot screw is for idle only - to set it properly, drive the vehicle for about 20 minutes to get it up to normal operating temperature - connect an accurate tachometer and set the idle speed at the desired RPM - turn the pilot screw in by 1/8 turn increments pausing 3 to 5 seconds between adjustments - when the idle speed drops by 50 RPM, turn the pilot screw out one full turn and it's set.

 

[Cavemancade]

The pilot screw is for idle only - to set it properly, drive the vehicle for about 20 minutes to get it up to normal operating temperature - connect an accurate tachometer and set the idle speed at the desired RPM - turn the pilot screw in by 1/8 turn increments pausing 3 to 5 seconds between adjustments - when the idle speed drops by 50 RPM, turn the pilot screw out one full turn and it's set.

What jets should I put in
Im at 500ft above sea level

 

[latebird]

The correct ones - there is not chart to indicate what jets to use with whatever mods you make - you make the mods and ride the vehicle to determine if the changes made require rejetting - then jet appropriately (either leaner or richer) using a dyno or your seat of the pants dyno - 500 feet above sea have will have no effect on jetting.