Snowmobile Fanatics banner

1 - 20 of 24 Posts

·
Registered
Joined
·
2,585 Posts
Discussion Starter · #1 ·
Im gonna be getting my hands on some new sleds, and i am wondering if i can get a question or two answered.
Picking up an ultra 688- it needs a piston, and has been bored out "to the max" (kinda scary, but whatever). Anyways, wondering where the cheapest place for one piston is? not sure about exact bore or year, but will this weekend.
Anyone know power of the 688?

Next, my mach z 780, i found a hole in one of the pipes- and i dont mean a small one. Bigger than a quater, for sure! anyways, i am now looking for replacement pipes. Also would buy some performance ones off somebody. Question is- what pipes will fit and work for this sled?

And a big question, been bugging the crap out of me ALL winter- how interchangable are belts?
One of my buddies swears that as long as its the same make(Polaris, Cat, etc) and it is within the same general power range (440-600, 700-900) then a belt will work. I dont think so, and ive been standing by my choice.. Whats the truth?
 

·
Registered
Joined
·
1,337 Posts
The Ultra's had 105 to 125 hp stock depending on which engine/pipe combination was in it.
 

·
Registered
Joined
·
2,585 Posts
Discussion Starter · #3 ·
Ok, and this one has been bored out too. Should go good.

I also need a tachometer for a 98 cougar 550.
 

·
Registered
Joined
·
4,331 Posts
not sure about your first two questions but the whole belt thing isnt right for example the belt for an 93 indy 500 and a 03 indy 500 are completely different
 

·
Registered
Joined
·
9,987 Posts
tdgbigfoot said:
Im gonna be getting my hands on some new sleds, and i am wondering if i can get a question or two answered.
Picking up an ultra 688- it needs a piston, and has been bored out "to the max" (kinda scary, but whatever). Anyways, wondering where the cheapest place for one piston is? not sure about exact bore or year, but will this weekend.
Anyone know power of the 688?

Next, my mach z 780, i found a hole in one of the pipes- and i dont mean a small one. Bigger than a quater, for sure! anyways, i am now looking for replacement pipes. Also would buy some performance ones off somebody. Question is- what pipes will fit and work for this sled?

And a big question, been bugging the crap out of me ALL winter- how interchangable are belts?
One of my buddies swears that as long as its the same make(Polaris, Cat, etc) and it is within the same general power range (440-600, 700-900) then a belt will work. I dont think so, and ive been standing by my choice.. Whats the truth?
1 - a - 688 is the size after boring .4mm over, they can be bored to 1.1mm over
1 - b - Wiseco piston and rings can be had for ~$110.00 at 1.1mm over

2 - no idea on mach z

3 - You are right.
 

·
Registered
Joined
·
1,337 Posts
They make a piston at .4mm OS? If the bore is truely machined in metric, typically, the oversizes should step by .25mm. Right? If you convert from english to metric, how many decimal places you carry out will make a difference also.
 

·
Registered
Joined
·
1,378 Posts
tdgbigfoot said:
Im gonna be getting my hands on some new sleds, and i am wondering if i can get a question or two answered.
Picking up an ultra 688- it needs a piston, and has been bored out "to the max" (kinda scary, but whatever). Anyways, wondering where the cheapest place for one piston is? not sure about exact bore or year, but will this weekend.
Anyone know power of the 688?

Next, my mach z 780, i found a hole in one of the pipes- and i dont mean a small one. Bigger than a quater, for sure! anyways, i am now looking for replacement pipes. Also would buy some performance ones off somebody. Question is- what pipes will fit and work for this sled?

And a big question, been bugging the crap out of me ALL winter- how interchangable are belts?
One of my buddies swears that as long as its the same make(Polaris, Cat, etc) and it is within the same general power range (440-600, 700-900) then a belt will work. I dont think so, and ive been standing by my choice.. Whats the truth?
The SPI pistons are a bit cheaper ($60.00/per) than Wisecos and OEM. I personally like to make sure my pistons are real close to the same weight and is the reason I would change all. As far as HP I'm going to guess bored w/o pipes 115, don't quote me.

If you can't weld a patch on it, then I would look at the SLP site, see whats what and then look on e-bay or related sites.

As far as belts always run what's spect for the sled. Just my .02cents[thumb]
 

·
Registered
Joined
·
2,585 Posts
Discussion Starter · #8 ·
Ok, glad to hear about the belt issue!
The bore of this ultra, i got it last night (guy was a serious d*ckhead) and he said i have to measure it to see how bored out it is.
This engine is the one that each cylinder is seperate, as opposed to all the cylinders being made together. Any tips?



Ugly_old_Poo_kid said:
tdgbigfoot said:
Im gonna be getting my hands on some new sleds, and i am wondering if i can get a question or two answered.
Picking up an ultra 688- it needs a piston, and has been bored out "to the max" (kinda scary, but whatever). Anyways, wondering where the cheapest place for one piston is? not sure about exact bore or year, but will this weekend.
Anyone know power of the 688?

Next, my mach z 780, i found a hole in one of the pipes- and i dont mean a small one. Bigger than a quater, for sure! anyways, i am now looking for replacement pipes. Also would buy some performance ones off somebody. Question is- what pipes will fit and work for this sled?

And a big question, been bugging the crap out of me ALL winter- how interchangable are belts?
One of my buddies swears that as long as its the same make(Polaris, Cat, etc) and it is within the same general power range (440-600, 700-900) then a belt will work. I dont think so, and ive been standing by my choice.. Whats the truth?
1 - a - 688 is the size after boring .4mm over, they can be bored to 1.1mm over
1 - b - Wiseco piston and rings can be had for ~$110.00 at 1.1mm over

2 - no idea on mach z

3 - You are right.
Not saying you're wrong, just want to make sure i understood you right- he called the sled a 688, does that stand for the engine after its been bored out? It is the SPX, if that matters.
 

·
Registered
Joined
·
9,987 Posts
The Ultra (and SPX) stock is 679.3cc, and called a 680. (66.6mm bore x 65mm stroke)

Bored .40mm over it is 687.5cc. (67mm bore x 65mm stroke)

Bored 1.1mm over it is 701.9cc. (67.7mm bore x 65mm stroke)

I'm going by what's available in my catalog.. Wiseco lists .4mm and 1.1mm overbore, SPI does not list any oversize pistons.
 

·
Registered
Joined
·
2,585 Posts
Discussion Starter · #10 ·
Ok, thanks poo kid.
How exacly do i measure the cylinder, or piston, for what size it is?
 

·
Registered
Joined
·
2,865 Posts
tdgbigfoot said:
Ok, thanks poo kid.
How exacly do i measure the cylinder, or piston, for what size it is?
You need a micrometer. If you don't have one they can be pretty expensive and you can probably go rent one down to Advanced Auto for cheap or you can stop by a local machine shop and see if they will measure it for you.
 

·
Registered
Joined
·
2,585 Posts
Discussion Starter · #12 ·
powdermadd440 said:
tdgbigfoot said:
Ok, thanks poo kid.
How exacly do i measure the cylinder, or piston, for what size it is?
You need a micrometer. If you don't have one they can be pretty expensive and you can probably go rent one down to Advanced Auto for cheap or you can stop by a local machine shop and see if they will measure it for you.
ok, i could easily take it to a local place and get them to measure it for me. Theres a few around.
 

·
Registered
Joined
·
9,987 Posts
You can get a digital vernier for about $12.00 from Harbor Freight and a set of internal micrometers for about the same, so you can really measure it for under $25.. Then you'll have to tool to start doing more stuff.

Then, when you need more accurate stuff, you can get better stuff.
 

·
Registered
Joined
·
2,865 Posts
Ugly_old_Poo_kid said:
You can get a digital vernier for about $12.00 from Harbor Freight and a set of internal micrometers for about the same, so you can really measure it for under $25.. Then you'll have to tool to start doing more stuff.

Then, when you need more accurate stuff, you can get better stuff.
I don't know if I would want to jeopardize anything that has to do with a motor, harbor feight tools aren't exactly top of the line. Sometimes it's hard to get a good reading if you've never used any micrometers or anything before too.
 

·
Registered
Joined
·
2,585 Posts
Discussion Starter · #15 ·
The ultra is a 98 i found out, and a SPX at that. Unfortunatly, i have no pipes for it, so i am in need of those...
 

·
Registered
Joined
·
1,337 Posts
I thought only the plain Ultra and touring was made in 98. So, I checked the sevice manual the Poo kid has links for and found no listing for the SPX in 98.

I really don't mean to cause any confusion.
 

·
Registered
Joined
·
2,585 Posts
Discussion Starter · #17 ·
picman said:
I thought only the plain Ultra and touring was made in 98. So, I checked the sevice manual the Poo kid has links for and found no listing for the SPX in 98.

I really don't mean to cause any confusion.
Ok. The guy told me it was a 98, maybe he was wrong. Its the agressive chassis, i have to check whatthe tunnel says.
 

·
Registered
Joined
·
9,987 Posts
My chassis chart shows the SPX as only a 97, no 98. And it is an aggressive chassis.
 

·
Registered
Joined
·
1,378 Posts
Ugly_old_Poo_kid said:
My chassis chart shows the SPX as only a 97, no 98. And it is an aggressive chassis.
X2
 

·
Registered
Joined
·
2,585 Posts
Discussion Starter · #20 ·
Ok, i went and checked the tunnel- its manufacturing date is 8th month of 96- which makes it a 97, correct?
 
1 - 20 of 24 Posts
Top