I'm in the process of diagnosing a problem in my in-law's '98 Summit X 670. Just took out of storage and it runs, but won't stay running. The thing is it will only run on the primer; no fuel is getting to the carbs just air in the lines. It will die if not continuelessly primed. I've disassembled and cleaned the fuel pump, checked the crankcase hoses/connections to the fuel pump and dpm air pump, all seems ok. If I hook up a hose to the impulse fitting on the fuel pump and suck/blow suck/blow etc it will pump fuel no problem, telling me the pump is good but the crankcase pressure is bad. Also, this motor had the pto seal replaced after a burndown 2yrs ago and ran fine ever since, but now suddenly this? So I was going to pressure test the crankcase and check for leaks, but I was wondering the best way to do this, and if there are cover plates for the exhaust/intake available from skidoo or if I need to fabricate them on my own??

There is a great article on this in one of the current sled mag's out on the news stands right now. Can't remember which one. See if you can find it.

There is an engine tester kit that most dealers will have P/N 861749100 which has all the covers and plugs. Personally, I use a pair of plumbing rubbers on the exhaust ports and smaller ones on the carb boots. Each size of the plugs I siliconed a tire valve stem (schrader valve) to pressurize the system with a small tire pump which has a pressure gage on it. You could use a tire gage to check pressure in a pinch. Use a spray bottle with soapy water to spray all gaskets and look for bubbles in the RV oil supply & return hoses.

That's a great idea Thumbdoctor!
I use a pair of plumbing rubbers on the exhaust ports and smaller ones on the carb boots.
Can you ellaborate on the plumbng rubbers you're talking about -- I haven't seen anything like that in hardware stores, have I?

Originally posted by LB700@Dec 4 2003, 05:40 PM
That's a great idea Thumbdoctor!

Can you ellaborate on the plumbng rubbers you're talking about -- I haven't seen anything like that in hardware stores, have I?
Rubber plugs for sinks

Well, duh..... :blush:

Now I get it -- thanks!

Looks like I'm off to the hardware store to get some plumbing rubbers! :p But like I mentioned above, the pto seal was replaced 2 yrs ago- about 500 miles- gotta love the past few MN winters... I took off the clutch and the seal looks rather bad. Check out the pic; any opinions it's shot?? Appears to have a little grease/oil around the lip, is this normal?

Ok, second try on the picture

Originally posted by rob7374@Dec 4 2003, 04:28 PM
There is a great article on this in one of the current sled mag's out on the news stands right now. Can't remember which one. See if you can find it.
I found the mag. It's the latest edition of Snogoer Canada. May not be available in the states but it does a good job showing what is needed and how to perform it.

I would either rebuild or replace the fuel pump b4 I went any further if I were you. Very doubtfull a seal is causing your problems. My guess is the pump is bad or has some crud in it from sitting over the summer.

Just a funny side note on finding engine vacuum / pressure leaks.

Q: How'd the shadetree mechanic loose his eyebrows and mustach?

A: He attached a propane bottle to his fuel pump primer line and used a match to find the leak, boom, found it !!!

look in the brand new snowgoer for jan. on page 36 under the how to section. they cover compression checks and leak down checks.

dan