2001 Mountain Cat 800 won't start

[dcullen]

Hello,
I purchased this sled about 3 months ago and it started first pull EVERY time, regardless of how long it sat. About a 2 weeks ago I rolled the sled into the driveway on some dolly wheels and cleaned the whole thing. I degreased the entire engine and hosed it all off. I was thinking about going out tomorrow morning to try and find a snowy road out in the mountains to just give the sled a test ride so I went out to the garage last night and tried to start it just to make sure it was ready to go. Wouldn't start. Made sure the choke was on, the kill switch was pulled out and the key was turned to run.Pulled it about 8 times and then began investigating. I pulled the plugs, spun it over a few times and put new plugs in. Before I put the plugs in I plugged one into the spark plug wire and grounded it out on the block. I turned the engine over and checked for spark. It was fine, and strong. The spark plugs I pulled out were wet so I thought maybe it was flooded. After putting the new plugs back in I tried to start it again, without the choke on, and still nothing. I have the belt off the sled right now, because I am replacing it, but I think having it on would only put more resistance on it and make it harder to start so that probably doesn't ahve anything to do with it. The engine compression seems good, and again it was running great about a month ago. The only thing that has changed between now and then is having washed it. I also had put sea foam in it about 3 months ago when I bought it to help stabilize the fuel and ran it then to get it into the carbs.

Have any of you had a problem like this? Any ideas on what to check?
Seems that I have the major components to an internal combustion engine, air/fuel/ compression and spark.

Any suggestions would be very helpful. I also have the factory service manual for it.

Thank you for your time,
Dan

2001 Mountain Cat 800 LE (carbed not EFI)

 

[akViper907]

hey

The 2 things I can think of logically that are now different than before is 1. SEAFOAM and 2. Washing it. Either the seafoam messed something up or water has gotten somewhere the sled doesn't like. I've used Seafoam on some of my vehicles, but never a sled or quad. My friend Mike put seafoam in his explorer and about 2 days later his check engine light came on. He replaced every sensor in that dang truck. He says he'll NEVER use it again. I only use the stuff on older vehicles that don't rely heavily on all the new computer sensor crap. don't know about a snomachine though. I always use STABIL for my fuel. As for washing my engine bays I NEVER spray directly into the engine bay, some people do, I don't. Did it once in my Nova and it died, took me 45 minutes to get it running again in the car wash bay!!!

 

[Mountain Thunder]

Sounds flooded, Pull plugs-key off- and pull over a bunch, blows out cylinders. then install dry plugs and hold Throttle wide open and pull pull pull.

 

[dcullen]

I tried that and still nothing. Any other ideas? How can I check the CDI box and other sensors for proper operation? I don't have an oscilloscope, only a multi-meter.

Thank you,
Dan

 

[Idcatman1]

It sounds like maybe the fuel in the carb float bowls dried out and the inlet valve is stuck shut. This used to happen to me every summer until I started putting Stabil in the tank and running it into the carbs. Some times the needle would stick open which was just as bad - flooded verses no fuel. Is the Seafoam supposed to be a fuel stabilizer and storage protectant? I looked on their web site and nothing was mentioned about that.

 

[Idcatman1]

I thought of a couple other things. If you have spark I don't think there is anything wrong with the ignition system. That model didn't have all the sensors that an EFI does so it can't be that. Try taking the caps off the carbs and pour a teaspoon of gas in the top of each one and then see if it will start. If it does but dies right away it means you are not getting fuel into the carbs. Hold the throttle about half open when you pull the rope.

 

[dcullen]

It sounds like maybe the fuel in the carb float bowls dried out and the inlet valve is stuck shut. This used to happen to me every summer until I started putting Stabil in the tank and running it into the carbs. Some times the needle would stick open which was just as bad - flooded verses no fuel. Is the Seafoam supposed to be a fuel stabilizer and storage protectant? I looked on their web site and nothing was mentioned about that.

Ok. Sounds like that might be it. Appears to have too much fuel. How can I check/ fix that?

-Dan

 

[Idcatman1]

Too much fuel can either be a broken diaphragm in the fuel pump which would let fuel straight through the impulse line into the crankcase, or floats in the carb bowls stuck down so that the inlet needle is wide open and won't shut off when the bowl is full. I would start with the carbs. Take the float bowls off and see if the floats move up and down on their pins freely. If they are stuck soak them in some carb cleaner and work them up and down by hand and that should work the stuff out that has them stuck. I have never had one of the style fuel pumps apart that is on this sled so I am not sure what to tell you there. Had more than one of the older style crack a diaphragm though and they are pretty easy to fix. I about went nuts tracking the problem down on the first one I ran into though.

Good luck

 

[dcullen]

So the sled stared and runs great again, just as it did before.
I have no idea what it was. The only thing I did is i took the top of the air box off and took the plastic plate with the 2 "J" shaped tubes out. Pulled the starter and on the second pull the engine fired right up. I then let it run for a little bit and shut it down. Put everything back together and it started right up again. So, I am not sure what it was. The sea foam is definatly making lots of white smoke, and that is normal. Read here, and note the picture of the car smoking like crazy.

http://www.seafoamsales.com/project...nes/cleaning-varnish-and-carbon-deposits.html

Even though that does say for 4 cycle engines, it says two stokes on the the can.

So after all that I installed my new kill switch with tether and I am ready for the snow!

Thanks for the help.

 

[Idcatman1]

Must have been gremlins, hate the little s.o.b.s

 

[arcticridr]

Has it recently been below freezing where the sled is at???? Smart valves in the tank may have froze due to water in the tank?? Their were problems with the valves on that year 800!!

 

[dcullen]

That's a good idea, because it has been below freezing here. But since the sled has been in my heated garage I am fairly certain that wasn't it. I'm wondering if maybe I got some water in the tank somehow during cleaning and since the water would sit on the bottom and be pulled out first to the carbs that maybe i just needed to pull all the water through before it got to good fuel.

Are these "smart valves" used in place of a manual fuel shut off valve? I have been unable to find the shut off valve for the fuel, even though my factory service manual shows it on the front of the air box between the carbs.

-Dan

 

[SledheadPaul]

Has it recently been below freezing where the sled is at???? Smart valves in the tank may have froze due to water in the tank?? Their were problems with the valves on that year 800!!

There are not Smart Valves on a CARBED sled. EFI only use Smart Valves.

 

[arcticridr]

OOPS my bad missed the EFI part!! Still think it has to do with the engine washing/water