My 2000 Artic Cat 300 2x4 is running badly!!

[donsinger]

Hello All:

I have a 2000 300 2x4 Red. The unit runs great when starting and for the first 1-3 minutes. Then, when starting from dead/idle engine speed, it dies like it is starving for fuel. If I pump the throttle about 8-10 times, it will then take off normally. If it stalls, it always start right up just by pushing the start button...no throttle is needed on re-start. BUT...it will fall on it's face again unless I pump the throttle 8-10 times. I have removed the carb and cleaned it...the float bowl had small amount of dirt in bottom. I removed the fuel tank and cleaned it...cleaned the shut-off valve and replaced the rubber fuel line. The air filter is new and the choke is working properly. Any suggestions to what is causing this to fall flat after warmed up when starting from dead idle position.....Thanks in advance for your suggestions

[DirtDemon]

Did you make sure to clean out EVERY hole and passage in the carb. It sounds like a problem with the pilot circuit, did you take the pilot screw out an clean in there? If so, you may just need to adjust the screw. Check your valve lash and your compression.

[donsinger]

To be honest....I am just a handyman when it comes to these machines. I did not remove any screws from the carb that may need re-adjusting. Where would I get the screw setting to check if it was set properly when it was rebuilt just over 18 months ago??

Thanks..

Don

[donsinger]

I soaked the entire carb in cleaner before I re-installed it. Please keep in mind that once I get this machine going from that idle speed, it runs very good...until I come to a complete stop and allow it to idle down...then the hesitation is there again. I did see a small "mar" in the pin going from the diaphram into the carb...if this pin is sticking...would that be a possible cause?

[DirtDemon]

Just to make sure, how is your air cleaner?

I assume the pin you are talking about is the needle, if so, this is not much of a concern to the low rpm operation, that doesn't come into play until about 1/4 throttle, and it will only have an effect if the imperfection is on the lower half of the needle. Anyhow, the pilot circuit controls throttle from idle to about 1/4 throttle, so this is where your problem most likely is. Soaking the carb in carb cleaner is usually not going to be enough to get any varnished fuel out of the small passages in your carb. The best thing to do is take the carb COMPLETELY apart and clean everything out by hand. Use carb cleaner followed by compressed air to blow out any passages that you cannot get into manually. Take the pilot screw completely out and blow through that hole too. Make sure to take out both jets and soak them before blowing compressed air through them. Be careful, they are tiny and if you blow them out of your hand, you may never find them. As far as specs for the fuel screw go, I would strongly recommend getting a repair manual, all that good info is in there as well as stuff you will likely need in the future. But one way to set it is to start at about 2 turns out, then with the engine running turn the idle up a bit and begin to adjust the screw inward untill the engine seems like it is going to stall out then back out a little to keep it alive. Then, begin turning the screw outward in small 1/4 turn increments, wait a few seconds to let your adjustment take affect. Keep turning out to the point where you find the highest, smoothest idle. Then re-adjust your idle setting.