Snowmobile Fanatics banner

1 - 8 of 8 Posts

·
Registered
Joined
·
4 Posts
Discussion Starter #1
Hello Everyone,

I have a 97 500 EFI that is my pride and joy. I've had it since '98 when I bought it with only 93 miles on it. Today I just turned 5000 miles on this machine. Until now, this sled has given me nothing but pleasure and wide smiles.

So here is the issues that has started for me:

Last week went for a ride and after about a mile it started to bog down on me on top end. I could only get about 6500 rpm and 40 mph.

Let it sit for a night, went for a quick rip and everything seemed fine. An hour later, made it a half a mile and same thing, very boggy.

Changed both fuel filters, went for a 10 mile ride, fueled up, and everything was fine (or I should say better. I noticed a slight bog on take-off, but I may have wore my belt a bit as I got stuck that night. Anyway replaced belt.)

Next day went out, made if half mile running perfect and it started to bog and wouldn't even stay running at idle. Limped it home ( 5500 rpm max; 25 mph max (on shoulder of the road).

Today I took it out and for the first 10 miles it had never run better. 7800 rpm in 3' of powder snow. Rode some trails, had good snap. After numerous drifts and bumps, I noticed that it was starting to get boggy and rpm's were fluctuating on top end. Thought at first that maybe some gunk was working its way through the fuel system. I have run 2 cans of SeaFoam in the last 4 tank fills this year. Got worse and worse, had to limp it home for 10 miles @ 5800 rpm max, 25 mph. I did notice that as I would pick up speed (barely) that it would start to gain RPM.

I should also note that before this horrible bog began, I had noticed that punching the throttle would give me my full 7800 rpm but then it would drop to 6800 after 40 mph. I had thought that it was maybe my clutch weights getting worn, but today in the powder, it held 7800 constantly (before it started acting up anyway). This leads me to believe that my clutch is fine and the drop in RPM has something to do with my current, bigger issue.

Haven't had much time to wrench on it, still in head scratching and research mode.

Thing I will try to trouble shoot:

Fuel pick-up line in the tank.
Noid test the injectors
Dropping resistor. (I would love to simply replace it, but can't seem to find one anywhere).
Dirty injectors?

Any thoughts or recommendation on where to begin would be greatly appreciated. Best snow we have had since I've owned the sled. Sure would love to enjoy it before it all disappears.

Thanks
 

·
Registered
Joined
·
28 Posts
I would check to see if there is a fault in the efi system. There should be a diagnostic led light on the ecu that flashes codes. Check there first.
 

·
Registered
Joined
·
9,980 Posts
When it gets boggy, pop the hood and look for a blinking light on the ECU. You might be getting an error from a sensor that putting the sled into safe mode.
 

·
Registered
Joined
·
4 Posts
Discussion Starter #4
I finally got back out for a ride tonight, it has been so cold lately!


So my sled ran fine when I first went out. Ran trails for 25 miles with no issue. Ran like a top!

After a bit, started to notice a slight bog between 20-40 mph. Low end and top end were fine. Was acting like it wanted some more fuel injection cleaner run through it.

Last 25 miles got a lil worse. When I got back home, I thought I would take a lap in the meadow. Got into some deep snow and then all the sudden I lost all power and with the throttle pinned, it stopped moving and killed. It started up again, but with the throttle pinned, I had 2000 rpm. I was barely able to get it home, and it was probably only 200 yards back home.

Got it back in the drive way and with the track raised and wide open--5500 rpm. Very frustrating! I am sure that if I go out tomorrow it will run fine initially.

btw, no light on the ECU.
 

·
Registered
Joined
·
383 Posts
Is the battery healthy and fully charged? And, the ONLY way to answer this is to have it tested. It needs to be put on a load test to ensure that it will deliver proper voltage under load, and then you have to measure to ensure it holds the correct charge.
 

·
Registered
Joined
·
16 Posts
I bought a 96 500 EFI and it does the
same thing ! No one can figure it out.
I haven't been able to ride all season.
Mine is sporadic and if you tug on
some of the wiring harness sometimes
it will correct itself.
Let me know what u find !

matt
 

·
Registered
Joined
·
4 Posts
Discussion Starter #7
Well I got back out for a brief ride this weekend, but only made it a mile before it started to bog down again. Made it home no problem and the weather was nice so I trouble shot a few things.

Battery...had oddly dropped from 12.55 from last week to 12.25 before my ride. Took it to Batteries Plus and they said the battery was "decent". Charged it @ 2A for a few hours before my ride and it was at 12.7V. Same once I returned.

Got home and looked at the fuel pickup line. Very clean and no signs of cracks or holes.

Took my plugs out. Left side wet and black, Right side dry and brown.
IMG_0634.jpg IMG_0633.jpg

Here is what really surprised me, a compression test revealed 100 psi on my left side, 70 on my right.
IMG_0632.jpg IMG_0631.jpg

Also of an ongoing concern, but not sure that it has anything to do with this boogy issue is the gas/oil blowing off my exhaust gaskets:
IMG_0636.jpg IMG_0635.jpg

SO, from what I understand these compression rates are much below acceptable. Does that mean that I need to rebuild my engine? Or could this loss in compression mean something else? Also, why is my boggy issue inconsistent?

Thanks all.
 

·
Registered
Joined
·
9,980 Posts
The 100 PSI side is about the bottom compression you wanna run.

The 70 psi side, is why the sled is boggy.

The oil leaking out of the exhaust is the reason for the low compression. If it's leaking out, it's not providing the lubrication the engine needs.

Get a top end rebuild kit with pistons and gaskets.
 
1 - 8 of 8 Posts
Top