1998 summit x 670. I really need more power help!!!!!

[Duddin]

I really need to get some more power out of my ol' sled as I can't afford a new one right now. Thinking of doing a pipe maybe twins and nitrous but is there anything else you suggest. I have heard that there is a problem with these motors electronics and doing pipe/airbox mods any help would be great.

 

[offroadmatt]

My buddy has one a year newer. Put twin pipes. Thing runs like a top.

 

[irideabigpumpkin]

Find a set of used jaws twins, the 98 and 99 summit x's are still one of my favorite machines.

 

[partsman]

I have a rotary can and pipe combo that will make that old 670 beat most newer sleds.Here's a pic for ya.If intrested call.
Steve (604)816-5682

 

[more-torque]

The JAWS 670 summit pipes are amazing. The head needs help too.

 

[himarker]

I have each: PPP 740 Big bore rotax and a Crankshop 840 rotax, both complete. Let me know if you're interested...they will wake up that summit for SURE.

 

[Duddin]

I think I should have specified more. I dont want to spend a whole lot so turbos and big bores are out Im thinking on a smaller scale until I can get a new one, its hard to justify spending more than about 2K

 

[JMCX]

Roll the case and put a longer 2" lug track on. 16" wide if it will fit. This will be your best bang for the buck and lots of good used tracks out there. Upgrade the skis if still stock.

Leave the motor alone or shave the head a little for some extra compression. People have accused popular head makers of basing their dome designs on the 670X motor.

I loved this sled when I had mine but to sit on one now it is unbelievable how bad the ergonomics are. Get some better handle bars on there, even if you have to use some Cat ones on your Doo. Don't get me started on the seat or throttle pull.

 

[B-Radical]

Is it still stock?

is it still stock?
if you havn't touched it yet there are hundreds of things you can do for less than 2K to really wake it up and make it more fun to ride. give us a little more info on your current setup. motorwork is not always the answer.

B-

 

[DWHalverson]

Clutch it, re-gear it, port it and stretch the track and ride. Done.

 

[Duddin]

Ok sorry i guess I should have given more details. Its got a 151 track and thats IT. I dont want to dump in a ton of money but my buddy beat my azz all over the place on his 97 RMK 700 (this is actually his account he is letting me use it) he has a bunch of motor work and nitrous. I dont want to beat him just keep up better. I plan on buying a new one in the next year or so but need something to get me through this season. If it helps I'm about 230lbs plus gear and pack.

 

[H20SKE]

Here is my suggestion after having several 670's from stock to full on moddy.

Jaws twin pipes--Union Bay head--shorty intake and 501 rotary valve and then jet accordingly to your alltitude. These few things will really bring it to life.

Good luck and enjoy.

H20SKE...

 

[himarker]

Im not tryin to push a big bore, and i totally agree with everyone else: there are tons of things you can do to a 670 to make em run well. Set up correctly they will for sure run with a rmk 700(depending on the mods to the 700)lol. If you are interested here are the specs on my motors: 1: PPP 740 big bore, rotax bottom end, jaws twins, 44's, complete with electrical and such. 2: Crank Shop 840, all built by C.S. top to bottom. C.S. twins, 44's, again, all complete with electrical and such. Both are FRESH(NEVER RAN ON NEW TOP ENDS) 740-$2250, 840-$3150 PM if interested.

Thanks,
himarker

 

[schu]

Mine has thunder products UFO's, stock rotary valve cut to 501 specs and indexed to some timing that I forgot long ago, 1 size bigger on the mains, needles dropped all the way, rolled chain case, front part of the tunnel removed, and some clutching I got from Big John.

It's not a new sled by any means, but for a 700 it goes really hard. The ufo's really made the midrange a bit stronger and it was pretty strong to begin with.

I personally wouldn't screw with twins, since the sled runs so well without them, but I've never have run them so I don't know how well they work.

schu

 

[Thunderguy BOOSTED]

I have a 1997 670 ski-doo which is bored out to a 740 union bay MOD twin pipes etc.

I what to turbo it just to get a little bit more power, but as it is it has 155HP

Do u have a turbo on yours?
Justin

 

[Modedmach1]

Port it, twin Jaws or CPI pipes, get a hold of Big Jon on here for clutching & gear it to 19/44. Cut or buy a 501 rotary valve. Put a head on it or shave the stock one. That is what I would do. I still run a 670 in my back up sled.

 

[Motley Doo]

Had a buddy that had a 670x that had slp twins, shaved head, watercraft rotary valves, and some mild port work done that made a 151 hp at the crank on a local dyno! That sled ran and is still running hard!

 

[DWHalverson]

Is the 840 a stroked 670/740 or is it their big bore based off the 800 twin?

Im not tryin to push a big bore, and i totally agree with everyone else: there are tons of things you can do to a 670 to make em run well. Set up correctly they will for sure run with a rmk 700(depending on the mods to the 700)lol. If you are interested here are the specs on my motors: 1: PPP 740 big bore, rotax bottom end, jaws twins, 44's, complete with electrical and such. 2: Crank Shop 840, all built by C.S. top to bottom. C.S. twins, 44's, again, all complete with electrical and such. Both are FRESH(NEVER RAN ON NEW TOP ENDS) 740-$2250, 840-$3150 PM if interested.

Thanks,
himarker

 

[holman6336]

One word.....TURBO!!! well, maybe thats not the cheapest option

 

[bigbones]

670 to 760 big bore and stroked

I have a 670 bored and stroked to 760 by Unionbay. Will sell cheap 206-276-0178.