1998 vmax 600 xtc mods

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JacobM03

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I have recently bought a 1998 vmax xtc 600 twin with 7500 km’s and was wondering if theres any mods to do that would be worth it? Sled seems to run pretty strong, in clean shape, lifts the skis on acceleration and I threw in a brand new polaris 1” lug track I found for cheap.

I checked the compression and dry both cyl were around 108 psi so I was thinking possibly a rebuild soon enough and maybe thinning out the head gasket, what is the stock gasket thickness and what would be a safe reduction for still running regular gas?

And I was thinking also plastic skis, would that be worth it if I get a set of used ones, currently have the stock steel with ski skins and looks like fresh carbides.

Also what would be the stock chaincase gearing? Would it be worth losing a tooth or 2 on the top gear and would that change the top speed and be worth the difference?
 
Here are specs charts: https://totallyamaha.com/snowmobiles/AAATuning Chart/Specs.htm

You can run a single layer or remove center and run 2 layers. It will bump compression but I would not run regular gas, only premium. 108 to 115PSI is pretty normal dry. Add a cap of oil in cylinders, pop kill switch and hold throttle Wide open when checking to give you the most acurate compression. Its more important that both are the same.

A good clutch kit would help.

Also check more here: https://totallyamaha.com/snowmobiles/aaTECH/TechIndex/sledTechIndex.html
 
if you are going to run 87 octane gas, leave the head gasket alone. you will get more out of clutching than messing with the head gasket.

i would do the reed stopper notch as it made my 01 sx500r start easier.

as to the skis, i have seen a lot of guys run c+a skis on that chassis. i do know that take off sr viper or sidewinder skis should bolt right up on that sled.
 
I read online that the 94-95 head gaskets were the same but 0.6mm thick and the 97+ headgaskets were 1.4mm thick, would it be safe to switch to the 95 gasket and run regular? And what kind of clutch kit would you recommend?
 
JacobM03 said:
I read online that the 94-95 head gaskets were the same but 0.6mm thick and the 97+ headgaskets were 1.4mm thick, would it be safe to switch to the 95 gasket and run regular? And what kind of clutch kit would you recommend?
Click to expand...
No matter what if you go thinner head gasket you will need to run premium. The gas today is so crappy I would not risk it.
I have never subbed in a gasket from the earlier years I always buy the correct year and remove the layers. Head gasket will give you more low end grunt and mid range.

Gasket mod: https://totallyamaha.com/snowmobiles/aaTECH/sxheadgasketmod.htm

Reed Stoppers: https://totallyamaha.com/snowmobiles/aaTECH/ReedNotch/Reed_Notch.htm

I have oem clutch kits ideas that you can piece together depending on your mods you are doing to the 600.
You can also toss on a can if you can find one and that will change your kit a bit as well.
 
MrSled said:
No matter what if you go thinner head gasket you will need to run premium. The gas today is so crappy I would not risk it.
I have never subbed in a gasket from the earlier years I always buy the correct year and remove the layers. Head gasket will give you more low end grunt and mid range.

Gasket mod: https://totallyamaha.com/snowmobiles/aaTECH/sxheadgasketmod.htm

Reed Stoppers: https://totallyamaha.com/snowmobiles/aaTECH/ReedNotch/Reed_Notch.htm

I have oem clutch kits ideas that you can piece together depending on your mods you are doing to the 600.
You can also toss on a can if you can find one and that will change your kit a bit as well.
Click to expand...
I just find it weird 94-96 ran with the 0.6mm gasket on regular and the switched to 1.4mm, hard to find information weather they changed compression ratio or what changed.

I will probably do the reed notch next time I tear it apart, ill also maybe play with the gearing, have a 22T and 21T gear on their way and ill see what I like. And quite possibly a set of skis like the one on my 2001 phazer.

Im going to call aaen tomorrow to ask for a price as I think they make a twin pipe setup for my sled the part # PIY 12080 if anyone know any information on it if its any good?

I also seen a brand new Power Block clutch on marketplace near me for a discounted price, would that be good instead of clutch kit?
 
JacobM03 said:
I just find it weird 94-96 ran with the 0.6mm gasket on regular and the switched to 1.4mm, hard to find information weather they changed compression ratio or what changed.

I will probably do the reed notch next time I tear it apart, ill also maybe play with the gearing, have a 22T and 21T gear on their way and ill see what I like. And quite possibly a set of skis like the one on my 2001 phazer.

Im going to call aaen tomorrow to ask for a price as I think they make a twin pipe setup for my sled the part # PIY 12080 if anyone know any information on it if its any good?

I also seen a brand new Power Block clutch on marketplace near me for a discounted price, would that be good instead of clutch kit?
Click to expand...
It could be many factors in the older 600. Bore, stroke or just head design and squish.

Power block will still need to be tuned to your mods.
 
I think you're Ok on 87 with the .8mm gasket, but if running the .6mm use premium.
These sled are hard on primary clutch parts so keep it maintained for max performance. Full throttle rpm is 8000 for best HP.
Also, check the oil pump drive as sometimes they wear off completely.
 
MrSled said:
Here are specs charts: https://totallyamaha.com/snowmobiles/AAATuning Chart/Specs.htm

You can run a single layer or remove center and run 2 layers. It will bump compression but I would not run regular gas, only premium. 108 to 115PSI is pretty normal dry. Add a cap of oil in cylinders, pop kill switch and hold throttle Wide open when checking to give you the most acurate compression. Its more important that both are the same.

A good clutch kit would help.

Also check more here: https://totallyamaha.com/snowmobiles/aaTECH/TechIndex/sledTechIndex.html
Click to expand...
I noticed that chart says the SXvenom has 2 cylinders....
 
JacobM03 said:
I just find it weird 94-96 ran with the 0.6mm gasket on regular and the switched to 1.4mm, hard to find information weather they changed compression ratio or what changed.

I will probably do the reed notch next time I tear it apart, ill also maybe play with the gearing, have a 22T and 21T gear on their way and ill see what I like. And quite possibly a set of skis like the one on my 2001 phazer.

Im going to call aaen tomorrow to ask for a price as I think they make a twin pipe setup for my sled the part # PIY 12080 if anyone know any information on it if its any good?

I also seen a brand new Power Block clutch on marketplace near me for a discounted price, would that be good instead of clutch kit?
Click to expand...
They thickened the head gasket because they were concerned about durability issues as the 94-96's would burn down if running them at midrange throttle. They added the TPS sensor in 97 to correct the burn down problem, but left the thick head gasket in unfortunately.
I had a 95 600, and I jetted in down from the stock 156.3 to 150's. I never had the thick head gasket update done. I was never the cruising type, so it never burned down. Ran 87 almost all the time.
 
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