What were the diferences between the standard 97 670 summit and the 670 X. I know that they lost some weight with the seat and the lighweight chaincase cover and the X definetally had more powe but I thought it was just from different a head and a pipe. I was told this weedend that there is not one part from the standard 670 motor that would fit on the X motor, is this true?
97 Summit VS 97 Summit X
- Thread starter Summit X
- Start date
M
Modedmach1
Well-known member
The pistons, cylinders & head are different on the X motor. THe lower end is the same.
I don't think there was a 97x. I know there was a 98 & 99x. Ski-Doo OEM parts fiche doesn't show an X in 97 either.
Check the Doo web site because they added a feature enabling parts lookup. Might be able to compare year to year for components in question.
Check the Doo web site because they added a feature enabling parts lookup. Might be able to compare year to year for components in question.
'98 670 Summit X - Flat-top pistons with head to match (more efficient combustion chamber), slightly different cylinder porting with a "window" machined into the rear lower cylinder skirt uncovering the rear transfer port, tunnel-ports in the case cleaned up slightly blending better into the cylinder transfer ports, 44mm carbs vs. 40's, different RV cover with more aggressive RV, different pipe and can, first Summit with DPM (which includes vacuum pump, tps, air inlet temp sensor, water temp sensor, different CDI module, DPM vacuum manifold and DPM tether), lighter seat, MXz style fuel tank, magnesium chaincase cover, 1.75" track vs. 1.5" stock summit track, different gearing, unpainted tunnel for less weight, first summit with a grab-bar on the handlebars, and aluminum rear grab-bar above snow-flap. '99 X package was virtually identical, with differences being slightly different DPM system, and minor carb changes to help eliminate flooding (different float arms).
I have owned several std 670 summits, and two '98 summit x's. I think the above info is pretty much correct. I mentioned "different' porting, but when I have compared std cyls to the X cyls, they looked identical in measurement, only obvious difference being the port window. I mention "different porting" because that seems to be something written in stone that everybody believes, and my measuring may be off. I have also heard that the rods are supposedly stronger on the X models as well, but I have never checked that myth out though. In addition I have heard that the X y-pipe is different as well, but have not noticed any difference dimensionally from a stock 670. If I am incorrect on any info, somebody please correct me!
I actually have a '98 x right now running standard style 670 cylinders with std 670 pistons and head because I blew off a ring land last year. Throwing standard 670 parts on it got it running within an hour, without having to wait a week for a new piston to come in the mail! Runs great. Cylinders I installed have been mildly ported, so I didn't notice any change, power-wise.
Thanks Zach. It is as I thought, basically a mod 670 motor from the factory with DPM instead of HAC. Looks like i won this battle with my brother. I should have bet something worth while. I just remember how noticably different these sleds were. Man they are an awsome sled. They just lost out to the longer tracks and lower center of gravity from the ZX.
H
HardcoreAK
Member
Stuff you guys might have missed:
The X model:
The X model:
- Factory 2" handlebar riser
- 2" Extended throttle cable
- The X had 9 tooth drivers and the 1.75" track, when the STD had 8 tooths and a 2" track, kinda weird I know but the 1.75" was better compared to the 8's vs 9's issue. besides the track being lighter...
- Ignition timing is different for the "watercraft" style head = more advance
- Chaincase cover is Magnesium vs Aluminum = half the weight
- Lower Sprocket was 43t vs 44 and "windowed" for weight reduction
- Top sprocket was 21t vs 23t on the STD and allowed a 72p chain vs 74p
- Oh yeah HPG T/A shock in rear
- Single pivot throttle lever for the 44 carbs
- Crankcase is factory tunnel ported and had 42mm openings in the RV cover
- Shortest Factory RV cover ever made and shorter carb boots
- X cranks have a black oxide hard coating - similar to nitride on a chevy
- theres no difference that I know of in the con-rods
- Pipe is different to match the higher rpm and the watercraft head/flattop piston torque curve
- also the rave springs are lighter if I recall correctly
cant think of anything else you havent already said
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