That was right around the Tim eof the swap from S chassis to ZX chassis. MPEM, DESS etc etc.

Two words pop into my mind instantly. " parts availability".

Ill have to defer to those with more summit experience than I.

Performance is significantly less compared to modern sleds.

Id take a close look at the lugs on the track and see if they're intact or ripped off. Long lugs don't take road abuse well, nor are they good trail sleds due to narrow ski stance.

All depends on previous maintenance, cleanliness, mileage and price. Then concern yourself with reliability and performance. Its a 25yr old sled afterall

 

Buy a parts sled to go with it. Dime a dozen

 

If going the X motor route (they had both a 670 and 670 X ) make sure you get a parts sled as well. Electronics are getting hard to find. I sold off my final two and it took minutes to sell on FB Marketplace. They were fun sleds, but I don't have the classic sled bug, so if I was looking to get into a good handling machine for cheap I'd be all over a 2004 on up Summit Rev.

 

Ok, the one I’m looking at the guy is saying that he was having trouble with the “magnetic key” should I be worried?

 

I would be worried It might be the DESS but it might be stator/control module. If so then you are looking for equipment that is getting very hard t find.

 

magnetic its not. More like a rubber like ring that snaps over a electrical post, through a chip to create a circuit. No "key" per se. Some are successful by putting foil under the cap to tighten it up, push and turn slightly and it may be fine. If it falls off in the wind for example its worn and a PITA to replace

Its a push on tether kill switch, It falls/pulls off the sled quits. It FAILS, sled quits. Also called a DESS. Digitally encoded security system, search it up here, it can be problematic. The DESS and MPEM need to match to run, swap one, your still dead on the snow.

Im not aware of any hack or bypass out there.

 

I agree. I’m currently fixing up a 98 Summit X. The moment the CDI gives me troubles, I’m converting back to standard ignition. I’m even doing a DPM and oil injection delete. I’m more partial to the non X models. Not a fan of the CDI system and even the piston/head combo.

 

What does it take to swap back to standard ignition? Also what is the DPM?

 

I think DPM stands for Digital Performance Management. It’s basically your high altitude compensation garbage. Works well when new, but with age they will give problems. In a simple explanation, it uses a vacuum pump to adjust fuel float bowl pressure for air/fuel. Three other sensors are used as well.

Converting ignition back is possible if you are mechanically inclined. You will need a standard ignition box and be able to convert a couple connectors. The HO engines have their flywheel key cut about one key width advanced. Simply remove the key and reinstall the flywheel without. Sounds silly, but it’s effective. You have to check timing to verify you installed it correctly. Once torqued, the flywheel will not move. Some say that getting an offset key will give you just enough to get timing in spec. I haven’t tried this.
When it comes to mod engines, reputable builders like the standard ignition.

 

Interesting, and yeah that DPM just seems like it would cause nothing but issues. And you were right that standard ignition seems definently a little odd to do, but could definently be worth it if I get any issues.

 

Just one thing you need to be careful with an ignition swap. The HO head is prone to detonation. Don’t ask me how I know, lol. Good fuel, read the plugs and even scope the cylinders with a camera.

 

Alright well I ended up buying it, it’s a 97 summit X. But now I’m hearing that the 670 isn’t a great motor and has issues with the crankshaft, can anyone speak to that? I have a spare crank but I’d rather not use it.

 

It's not a '97 Summit X. They only made the 670HO X models in '98 and '99.

 

'98 Summit X. Produced in '97, '98 model. Those are not the original skis. No airbox, which isn't good. The silver tube thing laying on top of the carbs is the DPM module. That thing is hammered, have fun.

 

Ok, thanks for the clarity on the year. The photo was taken mid carb clean and I do have the air box. Definently going to delete the DPM or atleast go through it.

 

She looks a little rough, you may want to do a compression test. Depending on your budget, I would look for a little nicer machine and keep that one for parts. If you only paid a $100 for it, you still did good on the deal. I can’t fill my mini van for $100. Lol.

just my thoughts.

 

Yeah, big job and good on you if you decide to tackle it but I'm with GMC. Looks like super deal on a parts sled. Get compression numbers as mentioned. You don't want invest anything else if the motor is weak.

The data plate is on the tunnel where your right foot would be when riding. It has the Mfg date. As Doug said, Mfg in 97 is a 98 model.

Here's a 98 shop book to help you out. Good luck.

Dropbox

www.dropbox.com

 

Thanks for the manual link. It all came back strong with compression test with 130 on each side. Also has an almost brand new 136x1.75 track. I also got a giant bin of parts with it. So I think I’m gonna fix this up a little bit then when it blows I’ll use it as a parts machine. Or who knows, maybe full restoration?

 

I also found out they have been using TCW3 which I understand is a no go. So I’ll probably flush the whole oil system and replace with amsoil interceptor.

 

I wouldn't get too carried away. TCW3 works fine in these.

 

130 psi isn’t that wonderful. It’ll run fine and you’ll get a season, but it appears wore. It should be in the 150psi range.
It also depends on how/if the engine was rebuilt at some point, it may have a thick base gasket. You may have to do a piston clearance check. That’s what makes a compression check hard to go by. A clearance check along with the compression will give a better indication.
You also want to make sure you hold the throttle wide open and give it a solid 5 pulls.

 

130 psi isn’t that wonderful. It’ll run fine and you’ll get a season, but it appears wore. It should be in the 150psi range.
It also depends on how/if the engine was rebuilt at some point, it may have a thick base gasket. You may have to do a piston clearance check. That’s what makes a compression check hard to go by. A clearance check along with the compression will give a better indication.
You also want to make sure you hold the throttle wide open and give it a solid 5 pulls.

Alright,I got all summer to get this ready for winter so if it fails the clearance check I might look around and see if I have a spare top end for a 670