Snowmobile Fanatics banner

1 - 14 of 14 Posts

·
Registered
Joined
·
32 Posts
Discussion Starter · #1 ·
I fried a crank bearing last season, which left me with two cyliders that need replating. I realize switching out the 680 jugs with 800 xcr jugs is somewhat common. My question is will my current psi pipes (wedge body) bolt up or are the exhaust flanges angled different and will the pipes themselves clear the exhaust valves. What other B.S. would a guy encounter with this swap? Thanks!
 

·
Registered
Joined
·
8,842 Posts
exhaust port is different, the xcr slopes down where the ultra comes straight out, xcr is a 4 bolt pattern,

with a little work you could make stock 800 xcr pipes fit.

if you get cylinders with heads and ves ass. all you need is new pistons and pipes and you are good to go.
 

·
Registered
Joined
·
1,219 Posts
not exactly true, if you got the money for an xcr yes, but its not all that much money or work given the fact you need 2 cylinders redone anyhow, and a stock xcr exhaust shouldnt run ya much dough.
would be royally impressed with the power of an xcr8, with what ive always loved the wedge body style.
would make an excellent summer project.
just gotta weigh your options and see which route you want to take.
 

·
Registered
Joined
·
32 Posts
Discussion Starter · #5 ·
bigwedgies said:
not exactly true, if you got the money for an xcr yes, but its not all that much money or work given the fact you need 2 cylinders redone anyhow, and a stock xcr exhaust shouldnt run ya much dough.
would be royally impressed with the power of an xcr8, with what ive always loved the wedge body style.
would make an excellent summer project.
just gotta weigh your options and see which route you want to take.
Thanks for the input. I will do a little research and weigh the difference in price. I realize I probably will cost more to repair what I have, but if the performance is a lot better it may be worth it.
 

·
Registered
Joined
·
1,378 Posts
The whole 800 project is a fairly easy set up, cylinders, pistons, heads, the only trouble is the pipes like Madcow stated. The angle of the exhaust port to mount the pipes. It's mainly the mag side pipe that will hit the top of the water pump.
 

·
Registered
Joined
·
8,842 Posts
to make an 800 kit out of the ultra cylinders you are looking at about 230 dollars a cylinder for boring and recoating, then you will spend about 50 bucks a head for resizing and shaping them, pistons will be about the same no matter what top end you use.

to go to the xcr 800 top end its about 200-300 per good cylinder with heads and ves assembly, then you just need pistons and pipes.

no matter what way you go the power difference between a piped ultra and a stock 800 xcr is very different. on paper they look like close in hp, but on the trail its day and night, the xcr top end has so much more low to midrange power.

ask some of the guys who rode the 800 xcr rmk i did, some of them siad they never thought a triple could have that much power down low.
 

·
Registered
Joined
·
32 Posts
Discussion Starter · #10 ·
That's exactly what I'm looking for is more low end. I have battled the ultras notorious low end bog for a long time. I have tightened up the sheave clearance, played with pilot jets, drilled out the pilot bypass. These things have helped, but I think the rest lies in the clutch. I think my wieghts are too heavy, I'm running hotseat L1 (59g) medium tip weights. I think a lighter wieghts with a heavy tip may help. I am only pulling 8100 rpm, but my pipes peak @8700 rpm. I've heard a set of UFO's help the low end also.
 

·
Registered
Joined
·
1,378 Posts
I'm just curious what size cut aways your running?

Edit:If your running the stock 2.0 cut aways (96 ultra sp) try going to the 3.0 cut aways off the stock 97 spx to get rid of that low end bog.
A buddy of mine has the same motor , but he kept the carbs off his xcr 600 sp trip/trip with 2.5 cuts, HUGE difference in performance between his and mine, in fact I'm going to pick up the 3.0 cuts, because I've been fighting the bog way to long.
 

·
Registered
Joined
·
32 Posts
Discussion Starter · #12 ·
ultrawillie said:
I'm just curious what size cut aways your running?

Edit:If your running the stock 2.0 cut aways (96 ultra sp) try going to the 3.0 cut aways off the stock 97 spx to get rid of that low end bog.
A buddy of mine has the same motor , but he kept the carbs off his xcr 600 sp trip/trip with 2.5 cuts, HUGE difference in performance between his and mine, in fact I'm going to pick up the 3.0 cuts, because I've been fighting the bog way to long.
I will definitely have to look into that. Do you know much about UFO's whether the anygood or not?
 

·
Registered
Joined
·
1,378 Posts
Tripledog said:
ultrawillie said:
I'm just curious what size cut aways your running?

Edit:If your running the stock 2.0 cut aways (96 ultra sp) try going to the 3.0 cut aways off the stock 97 spx to get rid of that low end bog.
A buddy of mine has the same motor , but he kept the carbs off his xcr 600 sp trip/trip with 2.5 cuts, HUGE difference in performance between his and mine, in fact I'm going to pick up the 3.0 cuts, because I've been fighting the bog way to long.
I will definitely have to look into that. Do you know much about UFO's whether the anygood or not?
I do not. Although the concept on what I've read about ufos seems to make sense, or should I say it looks good on paper.
 

·
Registered
Joined
·
32 Posts
Discussion Starter · #14 ·
ultrawillie said:
Tripledog said:
ultrawillie said:
I'm just curious what size cut aways your running?

Edit:If your running the stock 2.0 cut aways (96 ultra sp) try going to the 3.0 cut aways off the stock 97 spx to get rid of that low end bog.
A buddy of mine has the same motor , but he kept the carbs off his xcr 600 sp trip/trip with 2.5 cuts, HUGE difference in performance between his and mine, in fact I'm going to pick up the 3.0 cuts, because I've been fighting the bog way to long.
I will definitely have to look into that. Do you know much about UFO's whether the anygood or not?
I do not. Although the concept on what I've read about ufos seems to make sense, or should I say it looks good on paper.
Alright, thanks for the input. I am definitely going swap the 2.0 for 3.0 cutaways and see what happens.
 
1 - 14 of 14 Posts
Top