i've done some homebrew porting and headwork on my L/C polaris single,(400sport) runs strong but still tweaking clutch and jetting, wondering what some of you have done, good or bad.

 

Your porting will have everything to do with what the clutching will need to be, but also it has to match the pipe. If a polaris setup isnt matched all the way then your not going to get the most performance out of it. Please give some mods if any already and what the porting entailed. Thanks

 

I blended and slighly opened all the ports so theres a smooth transition, knife edged the intake bridge and outer intake ports, raised the exhaust port 1 MM, might go more and try and shorten pipe. to raise rpm.? I polished the exhaust port and flange. and polished the dome on the head. I cut my head 35 thousandths, ended up with 65 thou squish when assembled. Im running 110 octane for break in but am planning and hope it will live on 92 pump gas. is there a tach that will work on this engine? and what rpm should I shoot for? thanks

 

Bubba297 can tell you what tach to use and how to wire it up!

I've got a 2003 400 trailblazer.
The Aaen or HPD pipe won't fit because of head pipe is to large on the 2003 400.
So I setteled for the V-Force reeds and the Aaen silencer. The carb was jetted with a 240 main,
I put a 250 main in to start with. The needle was raised all the way, stock. I have stock clutching which
is a very low engagement rpm. K&N air filter, exhaust temp gage and 25" Buckshot mudders. This quad ran great to start. Now it has no hesitation, runs stronger and wheelies without problem even with the 25" tires. Before simple mods, you could't hold wide open without hesitation, now runs smooth and fast.
Just running unleaded 88 octane.
After a 15 minute warm up of easy ridding the exhaust temp runs 1200 after a 3/8 mile hard run.
Without the air box lid it will hit 1300, with lid and 30, 1/4" holes drilled in it, hits 1250 degrees. Just ridding in the yard the temp runs 600-1000 deg.

 

my pipe is stock with a DG aluminum silencer, and stock air box. i'm running a 220 main. seems plenty fat but still running 110 in it. interested in what others are running for squish and fuel used.

 

Hot Seat Performance only uses race fuel with 14.1 compression and 92 octane with 12.1.

Aaen performance does the same thing.