1998 Summit X 670 - buddy just picked one up

[Mort2112]

My friend is just entering the sport with a used 670 Summit X that he bought at auction. Preseason checks were all good, compression 150+ per side, no other issues reported. The only problem with the sled is a chunk is missing on the outer 1/3 inch of the left ski. We'll cut the outer edges from the other ski for now for symmetry's sake and trim the bad side. He doesn't want to dump a bunch of money while he is learning to ride (Understandably so), so things like pipes/cans and other mods are off the table for now.

I myself am a polaris owner, so I know next to nothing about these particular sleds. I do know they were highly popular when introduced, and from reading other posts that 670 Rotax HO is a great engine. I had suggested Redline Synthetic VES oil (we don't know what the previous owner used), and for fuel I run Chevron 91 Oct. with a stabilzer, and am suggesting the same for him (That is based on advice from the tech at Carl's).

I would love some suggestions on oil, what to look for, quirks in the class, handling characteristics, or any other advice you may have for this sled that I can pass on. Last season was his first on my wife's sled, a '99 600 RMK, and he decided he needed his own. Any help you can give me is great.

 

[Cheney]

What kind of riding? I had a 98 670X. Loved it. For mountain riding, remove the sway bar, (free) raise the handle bars (cheap) put a 144 track under it (Shop around for used stuff, don’t need to extend the tunnel) and new skis are a must. (I picked up a set of C&A Mountains for dirt cheap on eBay.)
Oil? Who knows? I ran the walmart stuff. Made it to 10,000 mi before it lost a crank bearing. You could still see the cross hatch in the cylinders.
Go thru it & check for wire / hose rubs and protect em. A must!

 

[Ride2Live]

to the top you go....

Just got done putting pilot jets in my wife's 1998 Summit 670. This sled is pretty solid but once it starts having electrical issues it gets expensive. I put a 1997 670 motor in that sled due to electric issues. That 670 "HO" motor was only made for a couple years and either they ran really good or were boat anchors which the one I had was. I run Chevron 2-stroke oil in that sled but Amsoil or BRP make great products as well(I wouldn't spend the money on Redline since it cost so much $45/gal and this motor would work great on a synthetic blend oil imo). Check out the clutch rollers in the primary and make sure their not worn or cracked. I would put springs in both clutches if you pull them apart. Check out the buttons in the secondary clutch as well if their worn replace them their pretty inexpensive. Other than that put 91 octane in it and run it. I think he will really like it I learned on a 96 Summit and they handle very well for when they where made.

 

[H20SKE]

Just did a similar deal on a 99 670x we found with 300 miles--if you shop you can do most of it inexpensive.

Clutchs number one job--get ahold of big john and tell him where you are riding,elevation etc... very important-the parts are inexpensive to make it really run-difference in a 670 that rocks and a dog. We did 8 inch risers--took the 136" suspension and moved it back and down 3" with brackets we built for the rear to accommodate the backset--added rail extensions and put on a 159" finger track--otherwise pretty much stock, engine wise. runs with the new 800's, of course youth helps there.

This is our families 4rth 670--ran redline in all--even the ole moddy 670 that we added the oil bottle for the rotary valve and premixed with avgas.

Great sled for learning.

 

[Mort2112]

Great thanks, I'll pass that on.