2000 Arctic Cat 300 4X4 - Won't Start

[Wonderwoman]

I am hoping that someone here can give me some more ideas. Our poor old red 300 won't start. We rode it, running fine, shut it off and now it won't start. Have gas to the carb and spark at the plug. Valves are adjusted. Still won't start. Tried a little starting fluid in the air chamber and still won't start. This poor old machine has 7000 miles on it. That has to be an Arctic Cat record! And I have never touched the engine besides setting the valves. Unfortunatly it looks like it only has 60 psi of compression. Don't understand how it could be running fine and then nothing. Someone give me a clue as to what I am missing or what to check. I was going to rebuild the top end this next spring but didn't want to do that this winter in a non-heated garage. Any help?

[Toddub]

7000 Miles and 60PSI, I don't think your missing anything but a heated garage.

[Wonderwoman]

With that low of PSI would that keep it from starting though?

[oxidized_black]

i would send the AC Guru (swampcat07) a PM and he may have a trick up his sleeve ...

[catcandu]

Those old Suzuki motors are famous for wearing the intake valve. Check the lash (.001-.003). If that valve is too tight, you'll loose compression. Also did you hold the throttle open when you did your compression check? They will read low if you don't.

[Wonderwoman]

Thanks, hubby did the compression test. I will redo this weekend and see what it says.

[swampcat07]

Change the spark plug anyways, sometimes it will spark outside but not under compression. Also try starting the quad in netural. Also make sure the battery is 100% charged.

Valve lash would be another thing to look into as stated above.

Don't worry 7k for an arctic cat is nothing.

I would also try heating the motor to see if it is just the cold weather do you have it in a garage? If not put a tarp over it with a large lightbulb under the tarp for a while and that should help.

[Wonderwoman]

Valves are adjusted to spec. .005 intake, .010 exhaust. Will try the new spark plug and recheck the compression tomorrow and do have it in neutral. Is the timing adjustable on these? I thought I read in the manual that it is factory set and no adjustment.

[swampcat07]

On the newer ones timing is adjustable with a key but if it was running fine before I would stay away from major mods until you get it running again.

Keep the jetting and the timing as well as any other changes for later when you have it running and can see what each change does.

Does the motor crank over fine?

[Wonderwoman]

Redid compression and could get it up to 80 psi if you dump a little oil down the spark plug hole. Ok took the top end off this weekend. Found out the intake valve was almost loose. Could compress the springs with my thumbs to get the valve free and out of the head. Looks like the valve face has worn and is sitting low in the head. Any advice here since I have never done valve work on any small engine. If this is the issue then I will take it to a professional to have it redone. While I am this far I think I will put new rings on the piston as well. Piston looks great.

[catcandu]

Since squirting oil in the cylinder didn't raise the compression much, it's your call on the rings. If it wasn't smoking, don't know as I'd mess with them. (I realize compression rings and oil rings do different things.) But it sounds like the valve is the culprit. Having the head re-done professionally sounds like a good plan, IMHO.

If you do the head and put it back together and still have low compression, pulling the head a 2nd time will go faster because it's all fresh in your mind and you probably still have the tools right there. To do the cylinder right you would need to mic it and will probaly end up with new piston,

rings, and maybe even cylinder. Again, just MHO.

[Wonderwoman]

The piston is low enough in the jug that I felt the cylinder wall. Smooth as a baby's behind. I would almost bet the machine on a valve issue. So for now it will be the valve job professionally done and see what happens. As much as I have read about these Arctic Cats and the valve issues I am hoping this takes care of it. Will let you know when I get the head back and put back together. Thanks for all the help.

[mikeexplorer]

Sorry not a record, my 2007 400 hit 11,000 miles this past November.

Hopefully when the valve is fixed you will be back up & running.

Mike

I am hoping that someone here can give me some more ideas. Our poor old red 300 won't start. We rode it, running fine, shut it off and now it won't start. Have gas to the carb and spark at the plug. Valves are adjusted. Still won't start. Tried a little starting fluid in the air chamber and still won't start. This poor old machine has 7000 miles on it. That has to be an Arctic Cat record! And I have never touched the engine besides setting the valves. Unfortunatly it looks like it only has 60 psi of compression. Don't understand how it could be running fine and then nothing. Someone give me a clue as to what I am missing or what to check. I was going to rebuild the top end this next spring but didn't want to do that this winter in a non-heated garage. Any help?

[Wonderwoman]

Ok, the head is in the shop. Got a new intake valve and two new valve oil seals. Machinist says everything else looks great. Will have it done in a week. Can't wait, hubby will be so happy to have his machine back and running again. As long as I am at it my 250 is acting the same so after we get the red one back together I am going to pull the head off my 250 and get it done right away. For less than $200 each to get these back up and running right it is well worth it. Maybe another 10 years will go by then with no issues. Still love the Arctic Cats even with the valve issue.

[mikeexplorer]

Sounds like a good price for the work being done. You should be in good shape after that. Should have many trouble free miles.

[Wonderwoman]

Alright, the head is back on and it is running. Have a slight problem with idle and it wants to backfire if you have it reved up and let off the throttle. I am thinking these are all carb issues. Reset the valve clearance twice now since reinstalling the head. So looks like time to look at the carb to get the final issues worked out.

[Wonderwoman]

Man these Arctic Cats run no mater what is wrong with them. Found out the Pilot screw had vibrated out of the carb. In other words running with no Pilot screw. Have one ordered should be here Friday. This old machine won't know how to act. Glad that it has just been little things. Will let you know how it runs with a pilot screw.

[mikeexplorer]

I am sure it will be purring like a kitten

[swampcat07]

I am glad to see it is up and running.

[Wonderwoman]

Hey everyone thanks for all the advice. The machine is running great now. Even took it up to the mountains and put 28 miles on it ridding double through mud and snow. Just can't keep a good Cat down. Now it is the 250's turn for a valve job. Got the head back on Wednesday and will go in tomorrow. Man I can't believe that they put such crappy intake valves in these motors. Well at least we should be good for another 5000 miles on these two.

Happy ridding to everyone.

[Wonderwoman]

OK the 250 is back together and running. I still have a carb issue on this one. It will run fine for a while then it acts like the choke is on. I have cleaned the carb twice now. Any suggestions?

[oxidized_black]

check the float height and needle and seat, or put a carb kit in would be what i would do ...

swampcat07 ???

[Wonderwoman]

Ok, it was the choke inside the carb. Was gummy and sticking. So both the 250 and the 300 are up and running great. Can't wait to get to the mountains with them. It is antler hunting season. Thanks again for all the help.

[ArcticCatboy03]

What is the screw on caps called that you have to take off to adjust the valves

[mikeexplorer]

The diagrams refer to it as an "inspection cap" Part number will depend on the machine model.

Mike

 

[Wonderwoman]

Yep inspection cap for inspecting/adjusting the clearance of your valves. Just don't over tighten it when putting it back on. They are only cast alum. and I busted one because I over tightened and couldn't get it loose.

[97kingquad]

On 1/4/2013 at 9:40 AM, catcandu said:

Those old Suzuki motors are famous for wearing the intake valve. Check the lash (.001-.003). If that valve is too tight, you'll loose compression. Also did you hold the throttle open when you did your compression check? They will read low if you don't.

My king quad 300 at 80k kms hasn't had a valve job yet, not did my 250 quadrunner