Help needed - Yamaha's fastest twin in early 90's?

Zachalyse

Zachalyse

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Maine
Need some help. Me and a buddy are on a never ending battle to out run each other on certain generation sleds. He is picking up a 1992 Ski Doo Plus X tomorrow and I need to start the search for something in that year, +/- a year to give him a run for his money. Since the early 90's were my "black out" years ie. college and bar scene, I was away from sledding

So, I need to know what sled I need to be looking for. Has to be a twin, similar to his plus.

Tks.
 
The plus x was a beast. Yes it was heavy as the PRS chassis was all steel, but I doubt anything yamaha made, even the exciter SX can beat one in proper running condition.

I had a 90 formula plus with the low hp 521 type 536 or was it 537. It was only like 75 hp stock. Having FAST port the cylinders and running bigger carbs and a bigger rotary valve made it FLY. I would think the Plus X was about the same speed as the built 521 I had. That sled ran circles around the big dogs of the day, ZR580, RXL, even a 96 ZRT600.

If I had to choose an Exciter SX or a PRS chassis doo when it got stuck, I would choose the exciter any day. At 20 years of age or so I thought I was going to have a heart attack the one time I got that plus buried in deep snow.
 
Not sure of the 1992 Ski Doo Plus X or Exciter SX stock Hp rating's but, I do know the original 87 Exciters were 75Hp and even at that Yamaha stated they kept the Hp low for reliability and greater torque in the trails instead of flat out top end speed. Quicker to 60mph or top end speed is another question.
 
My team mate ran a Plus X last winter in our oval racing. It was much faster than his Plus he had been running. He kept the "x" stock, and we just worked on the suspension and chassis. My 540 race sled (not stock) was faster, but the motor was built and I was pushing close to 100hp.
The motor is for sale.... I parted out the 540 this summer...
Monty
 
my '93 sx @ dynotech was 92 h.p. stock, w/ bender single pipe 102 h.p..
my '94 vmax 600 was 94 h.p. stock, 110 h.p. w/ bender twins & 118 h.p. w/ trail port & twins & carbon tech reeds.
i believe the plus x was around 120 h.p. stock.
bob
 
Put a pipe on it and keep the race short, its the best chance you have. Tough to overcome 20+hp though.

Meat
 
the only yamaha i saw that would whoop their asses back then was a 77 srx. to have to have something from that time period i'm afraid you have your hands full! hauck was running some fast improved exciters back then.
 
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I have really no idea what the HP for the plus x was but 120 seems a bit too much. I think they ran twin pipes on those but I would guess 100-105 hp would be about right. You would probably have your hands full with a exciter sx vs a plus x across a lake but challenge him to a 5 mile run through the woods and I think it you would be whooping up on him pretty bad. Those old ski-doos were not very nimble.
 
I searched pretty hard and couldnt find any specs on the plus x to try and establish a power to weight for both, but have come up blank.

Meat
 
just went thru my old dyno sheets from '92. i got my X's confused. the plus x was 580cc & 99.7 h.p. @ 7500 rpm & w/ 3 gal of gas & weighed 557#. the '92 mach1x was 670cc & 124.8 h.p. @ 8500 rpm & weighed 580# w/ 3 gal fuel.
sx w/ bender single pipe would be a good race. '94/'95 vmx 600 w/ slp, bender or psi twins would seal the deal!!
bob
 
It all depends on how long the race track is, also, is this on ice, hardpacked snow or powder, that will determine what you have to do to the sled (gearing clutching,carburator,suspension etc.) hp. is a factor, but, 20 hp difference isn"t something that I would worry about if I had to set the sled up for a head to head race. Just my two cents worth!!
 
bufalobob said:
just went thru my old dyno sheets from '92. i got my X's confused. the plus x was 580cc & 99.7 h.p. @ 7500 rpm & w/ 3 gal of gas & weighed 557#. the '92 mach1x was 670cc & 124.8 h.p. @ 8500 rpm & weighed 580# w/ 3 gal fuel.
sx w/ bender single pipe would be a good race. '94/'95 vmx 600 w/ slp, bender or psi twins would seal the deal!!
bob
Click to expand...
he said the sled has to be within a year apart, that would be a 91,92,93 yamaha
 
rman:
if that is in fact the case & he is letting his buddy dictate the rules then guess which one he should choose???
bob
 
the exciter sx 93 in a 660 ft race is a winner against any of them period and a race in the bush for as long as u want to ride yami is a winner again in those years bender pretty much owned the track with the exciters in those days and my buddy ice raced the exciters against the tripple polaris indys that could never get a hole shot on the exciter so it was allways catch up time for them and my buddy was no little boy 225
 
extremelyfastmax4 is correct, it is hard to beat the power to weight ratio of the exciter sx!
 
If the ski doo X is in good shape your in trouble with whatever you bring. Ski-doo made race setup manuals with step by step race setup for the "X". If thats done your done. Plus no way to know if it has the mods done by looking at it, cut rotory valve, carbs, head.. will all look stock
 
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