The X?

 

hahahahaha....ok, ok

 

I'm not 100% positive but I think the regular plus came with a 521, and the x came with the 583. Don't quote me on that though. I had a 91 formula plus and it was the 521.

 

http://www.dootalk.com/forums/topic/281437-1991-formula-plus-x-existence/

 

Sweet...thanks a lot...looks like its a 583 I have

 

Sweet...thanks a lot...looks like its a 583 I have

The 91 plus x had a 521 engine and the only X sled with twin pipes was the Mach I x it had a 617 engine in 1991 and a 670 engine in 1992!

Like was already stated the 1992 plus x was the first one that had a 583 it had a single pipe! Regular Plus had 580 engine with no rave valves!

 

Also the X' sleds had the Chro-Molly Birdcage..

 

So the larger engines were offered a model year earlier in the "X" sleds?

 

So the larger engines were offered a model year earlier in the "X" sleds?

No the 91 plus x was a 521 the same as a regular plus and the 1991 Mach I X was a 617 the same as the Mach I ! The only time that the larger engine was on the x was in 1992 the Mach I X had a 670 engine and the regular

Mach I was a 617!

 

No the 91 plus x was a 521 the same as a regular plus and the 1991 Mach I X was a 617 the same as the Mach I ! The only time that the larger engine was on the x was in 1992 the Mach I X had a 670 engine and the regular
Mach I was a 617!

Ok - that makes sense - the 1993 Mach 1 was the when I remember the 670 making its first appearance but it really was in the '92 Mach 1x.

 

The 521 liquid goes back to the 1983 Blizzard 9700, I think it has mikuni vm 40 carbs. a great web site is David's vintage sleds it has brochures (specs) on every sled known to man. www.vintagesnowmobiles.50megs.com . Click on brochures, click on Ski Doo and then click on the year and model.

 

the 91 formula plus x has 536 written right on the motor....so mydoo is correct....the larger motor must have been in 92