98 XCR 700 engine vs. 96 Ultra 680 - Snowmobile Forum: Your #1 Snowmobile Forum

ridgerunner · 05-14-2009, 11:42 PM

I have a buddy looking at buying a 98 XCR 700 that is in good shape for next to nothing because the clutch broke off the crank-shaft. He has a blown 96 Ultra 680 enigne w/ a good bottom end, and i just wanted to confirm that it is the same crank/case as the XCR 700. my thoughts are just a jug and head/piston swap, and its a bolt in. is this correct?

ridgerunner · 05-17-2009, 10:10 AM

anyone? i really would like some advice.....

Ultrafrozen · 05-17-2009, 10:43 AM

Same stroke, same bore,same displacement.

Ultra is case reed engine, as is the XCR.

'96 Ultra engine is EC68PL01 (SP & SKS) or EC68PL04 (RMK), '98 XCR 700 engine is EC68PL60.

Check out this site for parts info: Browse Once you find the part, click on "USAGE" to the right of item description to list other sleds where this part is used.

'96 Ultra has an oil reservoir for lubricated water pump. Later engines did not.

Can't answer if it is a direct fit as I've never done it.

ridgerunner · 05-17-2009, 09:33 PM

i knew about the site, but didn't realize that there was a "usage" tab, that is definatelly handy. i checked it out and the xcr 700 has the same crankcase as the 97 ultra spx, but not the 96, or the 97 special. i think this may be for more agressive porting? i know the xcr 700/ultra spx were triple/triple from the factory, but the sp (wedge) were single tuned? the crank is what is broken so maybe i'll just contact a dealer and see if they can cross referance the two... the cases could be different for porting or oil passage differences but still use the same crank right? especially if they are the same bore and stroke?

mattsdad · 05-17-2009, 10:31 PM

I think if you check , there is a different p/n for the pto lobe on the crank, and a different outboard bearing on the pto crank lobe, the 98 has a 4 line oil pump to oil the pto bearing, the cylinder are different castings as you suspected, different porting, also they have a different flywheel and cdi module you'll want the ones out of the 98 , the flywheel is lighter and the cdi box has a different timing curve for the 98 cylinders.

mattsdad · 05-17-2009, 10:47 PM

P.S. the crank is also different, the 96 crank has seals on it because oil reservoir water pump. The 98 crank doesn't have these seals. I think the newer case has channels machined to lube the waterpump, keep the 96 crank with the 96 case ,

ridgerunner · 05-18-2009, 06:52 AM

the 96 and 98 have different part #'s for the crank (all pieces and assembly) and the case. the origional hopes were to use the 96 crank/case with the 98 top end (cylinders, piston, etc). if the two have the same stroke, using the rods from the 96 would be okay? and if the 96 has lubricated waterpump, using that would be better than the 98 version, just have to make sure to add the line on the sled, cause if i remember right it is an extra external line. am i making sense of this?

Ultrafrozen · 05-18-2009, 08:32 AM

Here's one more refrence for you: http://chadt.us/snowmobilemanuals/ Check out the '96 to '98 Polaris manual.

If I remember right, Polaris had some problems with the oil reservoir type water pump lube system. That's why they changed to a fuel/oil lubed system supplied from the case.

I don't think you would be able to add the oil line to the PTO bearing as the oil passages are not there.

Good job mattsdad. Nice to see the experts pitching. I'm just a "wanna-be".

mattsdad · 05-18-2009, 10:29 PM

the 98 crank wasn't the greatest either , they changed again in 99 for the 700 and the 800 on the pto end with a deeper and larger(14MM) tapped hole and a stronger clutch bolt. Like ultra frozen said the hole and fitting are not on the 96 case, but I suppose you could add them, another possibilty would be to cut the seals off the 96 crank and put it on the 98 case, I haven't tried this but I have heard of it. Again remember to use the 98 flywheel and cdi box with the 98 cylinders. The mag end of the crank is the same so the 98 flywheel will bolt up. The 96/98 manual with tell you the correct ignition timing for that engine. Swap the carbs too, they are jetted differently and check they probably have other compnents different for that engine (ie slide cut away, pilot jets , jet needle etc) again good luck and these are just suggestions , good idea to check with your polaris dealer for the last word

mattsdad · 05-19-2009, 02:37 AM

p.s. the 98 stator plate must go with the 98 flywheel, as the 98 flywheel is a smaller dia..thus the lighter weight and faster reving..looking back at the original question, I guess if you just wanted the engine running you could just put the top end on the 96 bottom end and it will work but would result in a less dependable engine..in my opinion..I also think the 98 ignition should stay with the 98 cylinders. The stator plate, flywheel with bolt up to the 96 case and remember the 98 cd unit must go with the 98 flywheel and stator plate, good luck

racing_kidd · 06-22-2009, 06:53 PM

I have the 96 sks ,and 98 touring engine for my 1996 ultra sks and yes everthing above is true, jst have to add and ask a one thing,

The mag side bearing is a differnt number, I can let you now next month why.
I am rebuilding the 96 sometime and probly accomidate for the external pto oil way and replace the two outer crank bearings, and replace the mag side crank end piece, as the bearing plopped off with the origanl owner to cause the blow up,

I want to know where the seal is on the 1996 crank case because this winter I ran the 1998 engine and oil pump, but with the 1996 water pump, Now I think about it im glad i never refilled the ow-40 4-stroke lube oil again after installing in the pump itself even tho the two models call for the same water pump,
Did I put 4-stroke oil into 1998 my crank? Or is the oil sealed in the pump

mattsdad · 06-23-2009, 12:26 PM

yeah you probably sent a little 10w 40 thru the center and mag cylinders, the seals are on both sides of the gear that drives the water pump, probably was dilluted with fuel and two stoke oil