Factory Twin Pipes on Summit?

[captain dunbar]

Just picked up a set of twin pipes for my summit 800. Its all stock w/ exception of boyesen rage cages. Can i leave jetting the way it was stock to test the pipes? riding 8000-9000ft 35 deg temps 400 main jets. I have heard so many mixed emotions about the twins, so thought i would try them out for myself!

 

[Reeb]

Get ahold of Gus Bohne on here, or call the race dept and see what they recommend.

 

[captain dunbar]

Tried Gus and inbox is full. Any contact info. for race dept.? Thanks!

 

[Reeb]

Sorry, I don't. Didn't keep any contact information when I left the dealership.

 

[winter brew]

Number should be in any Doo race manual....I don't have one here to look it up.

 

[captain dunbar]

ok. thanks. started with 420 pto 430 mag dropped clip i spot on needle. see what happens this weekend! sounds ok in the shop at 3k elevation.

 

[Reeb]

Number should be in any Doo race manual....I don't have one here to look it up.

And on that note!

Yvon Petit
Race Tech
450-532-5100 ext:5803 is Yvon's # in Valcourt.

 

[sledneck2012]

What did you end up with for final jetting?

 

[madmini660]

What did you end up with for final jetting?

yah i'd like to know this as well thanks

 

[worx53]

jetting twin pipes

If you are running a stock summit head at 8000 feet and the factory rack carbs you can run lower main jets than 400's. At sea-level we can run 420-440 main jets with those pipes at that temp. we also add a .020" shim under fixed needle (or raise needle one clip) at sea level and advance the timing a little..

 

[tukernater]

If you are running a stock summit head at 8000 feet and the factory rack carbs you can run lower main jets than 400's. At sea-level we can run 420-440 main jets with those pipes at that temp. we also add a .020" shim under fixed needle (or raise needle one clip) at sea level and advance the timing a little..

Did you get a noticable gain?with these pipes.

 

[worx53]

yes, but better yet with crankshop mondo twins and running a little higher compression them cutting fuel with race gas. 10 hp gain with crankshops.

 

[worx53]

FYI: The ski-doo race shop ran taper bored mikuni d-slide race carbs and 16.5:1 domes with these pipes and jetting was 350-360 at something like 25 degrees f and at sea-level. I dont think they ever tried trail type compression or rack carbs.
A full race ported motor at 16:5 to 16.9:1 and these carbs will run usually a 380-410 at same temp and altitude depending on power.

 

[Grizzly11]

what jetting did you end up running?