Just lookin for some feed back on the 99 670 engine. I am lookin at a 99 670 summit to slightly mod up. Good / Bad engine....what is the best pipe or pipes.....it has a 136 inch track that will be changed to a 144....would the new 16 inch wide track fit in that tunnel ?
99 670 Good / Bad
- Thread starter razor
- Start date
YES, this is the best motor ski-doo ever built. They are very dependable and run very strong when set up well. They are great on gas, best bottom end of any sled, and still run with or beat the newer 800's. The tunnel will accept a 16 wide track with some grinding of some bolts and rivet and put washers in between the skid and tunnel to spread the tunnel a bit. Crankshop twins, and psi twins both work well and raise the port timing a bit and cut the rotary valve, cut the head and it will rock.
gg
gg
A
aktreekiller
Well-known member
yep
I rocked a 670x in high school. I lived where I could ride everyday, so I put 7000 miles on the girl. I lost the bottom engine seal twice, and some other odds and ends. Don't flip it, its a pain in the *** to start again. One of the best engines in my opinion.
I rocked a 670x in high school. I lived where I could ride everyday, so I put 7000 miles on the girl. I lost the bottom engine seal twice, and some other odds and ends. Don't flip it, its a pain in the *** to start again. One of the best engines in my opinion.
Absolutley loved the 99 670HO I owned. Wished I would have kept it. Keep the carbs cleaned out and you will never have a problem!
dont pick on me because...
i ride a snow hawk but one of the guys in our group has a 99 mxz670.just turned 11,000 miles, yes 11 thousand! no troubles,never been apart! i have a formula z 670 with 3500 miles and a broken speedo cable for the last 2 years or so...maybe 6,000+ also never been apart and i love to hold her wide open most of the ride. this sled has even been hit head on by a car and still runs great! check out pics in my profile of it....rode home 15 miles after it happened!
i ride a snow hawk but one of the guys in our group has a 99 mxz670.just turned 11,000 miles, yes 11 thousand! no troubles,never been apart! i have a formula z 670 with 3500 miles and a broken speedo cable for the last 2 years or so...maybe 6,000+ also never been apart and i love to hold her wide open most of the ride. this sled has even been hit head on by a car and still runs great! check out pics in my profile of it....rode home 15 miles after it happened!
Heavy weak rear suspension. Do something about that.
Change the rear springs to MXZ springs.
Do a skid relocate and get the angle of attack lowered. It did that to mine and now it jumps ontop of the snow and stays there without trenching.
If your going to 144"might as well go to 151"
Simmons skis help alot as well.........
I still have my 99'X and the motor is bullet proof.
I have been told that actually Skidoo got the pipe pretty good in that year and you only get marginal gains with an aftermarket pipe. The suitcase silencer is a different story though. You can take alot of weight out of that thing if you go aftermarket.
PM Big John, he will get you set up with clutch parts.
98/99' X's were brutal on belts. I regularly go two seasons on the same belt and you can actually touch the clutches after long pulls. Without clutch work, you could fry an egg on either clutch.
A little tweaking and you have yourself a great sled, even with todays crop of awesome new sleds......
They do have lots of power but they are kind of heavy (compared to the REVs) I had a 99 mxz670 HO and it gave me nothing but problems I rode it two seasons and put two cranks in it and three top ends. (must have been a lemon)i've had a 99 summit x since new ..love the machine ..did a skid relocate 151 track bar riser and had big john set me up this year with clutching and the thing rocks...great sled only complaint with it is the ride an on the rough trails
stma07 You probably put in Doo's reman cranks huh? I have had terrible luck with crap put out by the factory. Cranks mostly.
670 for the displacement runs pretty good.
jon
670 for the displacement runs pretty good.
jon
loved my 99.. it was bulletproof.
Big John really mades that sled crank.
I had him put on a 151 and loved it.
but you could get into a rev chassis for what you have to pay for the 99 plus the mods, give or take a few hundred bucks.. Get a REV.
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VS
Big John really mades that sled crank.
I had him put on a 151 and loved it.
but you could get into a rev chassis for what you have to pay for the 99 plus the mods, give or take a few hundred bucks.. Get a REV.
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VS
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