99 T-Cat with 1004 motor Jetting Help

[ThunderZRT]

Im about to drop a freshly rebuilt 99 Zrt 800 with a 1004 kit on it in my 99 T-Cat chassie. I'm running 38mm roundslides , black magic trail pipes ,snow stuff silencer, gutted airbox with stock lid. I put all new seals on the motor. I'm asking cause I burnt down a case ported, cylinder ported 992 motor last year with 39.5 rounslides, running 480's with q5 needle jets. I wanna jet this motor safe. I'm going to run the 38mm rounds and putting a stock air box lid back on. I don't trust the airbox lid I have that is cut. It is cut more toward the front of the box, where the power breather is more toward the back. Any suggestions would be appreciated. Maby some one has this set up on their 99 T-Cat.

[Green Terror]

never ran a 1004 but ive run 992's for a long time and i burnt down the same motor as you with the same jets. it was in a 94 t cat with psi modblasters, porting and 39.5s. that was with about 190psi though and 2 deg advanced timing, running 480s was on the ragged edge. sled was never beat though (this was 1996) the next setup was essentially the same but with stock timing and 135psi, and i ran 460s for a while but it eventually cooked a piston too. so, 500 mains went in, and no problems ever since then. stock needles. sled rolls off trailer and runs 130's all day, no tuning, no plug checking (unless its colder than -15) 510 mains wouldnt hurt to be honest. 520 may be even safer it just depends on the temperature. if it was me i would try your 480 mains in the 38mm carbs and see how that runs on a day where its only a few deg below freezing. look at the plugs and piston wash, and go from there.

[blaine]

Don't discount the needles and where they are positioned. Most of the time your lean spot is in the middle. Also, There was an article one time that Mikuni jets were off from 500 to 520 sizes. I cna't remember the details but it was something like the 520's actually flowed less fuel than the 500's. I just go from 500's to 540's when jetting. Maybe that issue has been taken care of.

[Fearless 1000]

Always run some good fuel to be safe. VP 110 put a gallon to 4 gallons of high test pump gas. Check your piston wash if you are running the fine line. I run Q-5's with 420's on my 1000 with some race fuel can run 2500ft pretty safely.

[ThunderZRT]

Thanks, guys I was thinking 500s to start just to see how it runs I don't want to burn this motor down. I might even run q8 needles, I can always jet down I guess. I kinda wish I had a stock airbox but bought the chassie with the cut lid.

[C-Cat]

Originally Posted by ThunderZRT

Im about to drop a freshly rebuilt 99 Zrt 800 with a 1004 kit on it in my 99 T-Cat chassie. I'm running 38mm roundslides , black magic trail pipes ,snow stuff silencer, gutted airbox with stock lid. I put all new seals on the motor. I'm asking cause I burnt down a case ported, cylinder ported 992 motor last year with 39.5 rounslides, running 480's with q5 needle jets. I wanna jet this motor safe. I'm going to run the 38mm rounds and putting a stock air box lid back on. I don't trust the airbox lid I have that is cut. It is cut more toward the front of the box, where the power breather is more toward the back. Any suggestions would be appreciated. Maby some one has this set up on their 99 T-Cat.

This is what I ran. I also closed off any air from the engine bay from getting into the air box. I also cut down the snow shelf towards the bottom of the air box, to get a better feed from the bottom. In the 2nd pic you'll see some plates I installed uder the cowl to not let warm back in, and the SLP screens for the cold air on top. In the 3rd pic you'll notice almost all of the sleds besides the green F7 and my 2001 T-Cat were tied down. I used an AD Bovin (also makes the sled handle way better on the trail) coupler kit on the suspension so not to flip over backwards on take off with .750 predator track and 1.20 chissels. When trail riding I'd switch to a 1in. predator with 1.343 roetins. As far as jetting I ran bored flatsides on an Arnies Cat House 1100 cylinders with Donny Tucker Heads. Man those cylinders rocked for stock Cat cylinders. Donny Tucker told me it actually a 1098 bigbore when he did the heads to run on (12:1) pump gas.