I had some carb issues earlier and believe I have resolved them. I cleaned the carb and replaced the needle and seat. After setting to service manual specs it has been running great.

I plowed snow most of the day yesterday. Toward the end of the day the machine was not idling correctly. I tried to adjust but could not get it to idle. As long as I was running it was fine, I just feathered the throttle to keep it running. If it died it started up just fine and I continued plowing.

After sitting in the shed last night it will not start. It cranks fine, has spark and fuel and seems to have compression-I have to see if my compression tester will fit the threads for the plug. It has been burning a little oil, past the valve seals I am fairly certain. I did the work on the carb because the needle and seat on the float went bad and filled the crankcase with gas. I think this caused the valve seals to harden and start leaking.

When I pulled the plug it was fouled, I replaced it.

I have never had the valves adjusted or any work done on this machine, outside of what I have mentioned.

Help me keep my sanity!!!!!! I have snow and no machine--AAHHHHH!

 

Pull your carb and intake off and look at the back side of your intake valve. If it's covered in oil or deposits you probably found the problem. Also check your valve lash. It's a real pain to do on this model without bending your feeler gauge all up but I'm sure Arctic Cat will sell you the "special tool" you need at an outrageous cost...

 

Sounds like you might have gotten some trash in the idle circuit somewhere. Some of these passages are very small. I have taken apart a piece of multi strain wire, remove one tiny wire, and use it to run down all the passages on the carb, then use carb spray to blow thru it. Also, if your quad is leaking oil by the valve seals, it problably from being 9 yrs old. But the gas problably didn't help. Also, the best way to keep fuel out of your crankcase is to turn your fuel valve off when not in use.

 

fuel should not be filling your crankcase. make sure you got your float height correct. and just because you have good compression doesnt mean your oil rings are good. the top two rings provide compression while the lower set are oil rings and if they are bad you will burn oil and foul plugs but it will still have good compression

 

The fuel in the crankcase had been resolved over a month ago.

I am just trying to diagnose the no start now. I have not seen this machine do this before.

The temps have been teens to twenties for a few days. I plowed snow for several hours. It started to not want to idle and I had to keep working the throttle to keep it from dying. I tried to adjust the idle. If I adjusted up it would run but at rather high RPM. When I adjusted down it would die.

-I removed the carb and brought it inside to warm and drain to insure no water was in the carb.(No water was evident in the float bowl when drained)
-I checked the fuel filter to see if it looked like ice was forming in it(no signs of ice)
-I pulled the plug. It was fouled and I replaced it. Had a black tar like fouling from burning oil.
-I checked spark by pulling the plug and grounding on the head. Spark looks good.
-Engine cranks fine and seems to have compression.(I will try to check this with a gauge today.)
-I tried starting fluid with no luck.

Could water get in around the stator some how and mess with the timing?

 

make sure your intake is tight around carb and your air filter is tight and clean and charged. and be sure when you check the compression you have at least 145 pounds

 

You said yo have used starting fluid? I believe that is not a good suggestion with an ATV. I don't recall why just remember seeing someplace it is best not to do it as it can damage the rubber seals, gaskets and things.

But, if spark looks good try removing the air filter and spark plug and squirting a bit of fresh fuel into the cylinder, reinstall the plug and try it again do not put the air filter on. When I have done this before I used chainsaw fuel because the oil can help with compression if you think its low.

Out of adjustment valves would cause HARD starting but it would still start but idle horribly. So a compression test could rule out (or in) compression.

Also, if your compression tester fits the threads (it is usually the smallest threads on the tester). Test the compression what I like to call "dry" then note the reading then squirt a little engine oil into the cylinder and test it again. Compare the two readings. If they are too far a part then something is fishy.

Swampy

 

I hadn't heard any problems with starting fluid, but it makes sense it might be harmful to the rubbers in the carb boots. After cleaning the carb and replacing the needle and seat it has been running so good.(And getting the adjustments right after being one turn off.) I have taken up plowing a local bank and a couple other businesses. I tried the starting fluid as a last ditch effort to help diagnose the problem. I knew if it fired on starting fluid it was likely a fuel issue.

I will obviously have to check compression cold so the actual number will not be accurate to specs.

It just seems odd that it was driven to where it is now parked. My first thought was water had frozen the fuel line. That is not the case.

I have not gotten to check compression yet, my water froze in the house yesterday and I had to work on that.

 

Was it smoking the last time it ran, and did the smoke have a color? Light blue is oil being burnt. Black is fuel.

 

Update:

The compression was low. I took it to the shop. One valve is bad and they said the nickel is flaking off the cylinder and piston. Since it is nickel plated they said it can't be honed so the cylinder and piston have to be replaced and the valves replaced.

The shop quoted $1200 (+/- $200) to preform these repairs.

I can get a new engine for $2000 plus freight. That happens to include the transmission and all on this model.
I would to the engine swap myself, the mechanic at the shop said that is a 15hr job.
So what is a guy to do?