Let me start off by saying that I did not start this thread (as you see it is my 1st post here) to flame AC. I am just having problems for two years now and I am fed up. So I thought I would come here to get answers.

Okay here is the prob. I own a 01 AC 300 4X4 that I bought in Sept of 00. Shortly after buying it, I started having problems with it not wanting to run correctly. I.e. after riding awhile it would start back firing, wanting to die if you gave it gas, major of loss of power. Well it was a very sprodaic(sp?) problem, but several times left me limping back home or to the truck. I took it back several times during the warranty period (the whole time getting an earful from my dad and brother who own Hondas). The dealer never could find anything wrong nor get it to do the problem. Well this went on most of last year. Finally I let the dealer have it for a couple of weeks to ride. He rode it one day for like 20 miles and finally got it to do it. Looked it over and told me it was the carbuetor. He said he took it off and it looked like sea form in it. So he told me it was the gas I was using and some other things I wasn't doing. So I was okay that must be it. Well it wasn't much longer and it was doing it again. So I called him told him about only to get the same answer. The Gas. Well needless to say it is still a problem. Saturday it had the problem when first starting out (something I expect now) and then it had the problem again later on after we had rode for a while. I had to limp home backfiring and sputtering all the way home while my bother cruised along on his honda. It is really humilating.

Okay Here are some questions:

1. Has anybody else having/had this problem.

2. If it is bad gas......then I have the sh#ttiest luck in the world, because I have been getting bad gas for 2 yrs from different places.

3. See #2.... then why isn't my bother's hondas having problems (2 300s and a foreman)

4. Do the carbs on these have to be cleaned once a month or something. In two years and 700mi the carb has been cleaned at least twice maybe 3x.

I really don't want to talk to my dealer again because I sure he will tell me the same thing - gas and carb(I have asked him why the hondas aren't affected and never really got a straight answer). I would like to get a hold of AC but the website doesn't have a number for them.

I pretty much want the prob solved or the 4wheeler gone. I still own a little on it and trading it off for a honda right now is not an option. I am trying to save up to buy me my other hobby - high performance boat.

Other than that it does what I want too and I like the options on it. That is why I chose it over a honda and price too. But I guess you get what you pay for.

 

Now that I don't see.... all manufacturers have their problems...

but to your problem... it sounds like a fuel/air problem. you may have some crap that in the fuel system somewhere.

Trust me it has nothing to do with Cat quality....its just one of those things....

 

Hello neighbor, I see you are not having much luck with your Cat. I would suggest making sure the vent lines are open. There is one in the fuel tank that goes down kind of low and has a tendency to get some mud in it. Take it off and blow through it to make sure it is clear. Then there are 2 on the carb, they both come up to a seat grommet in the frame. Take them both off and make sure thay don't have a blockage in them. I would suggest taking them off at the carb also then blow through them. There is another line coming off of the bottom of the carb, where this line atatches there is a screw in the float bowl of the carb. Loosen this screw and fuel should come out of the hose if the gas is on. Catch this fuel in a clear container. Make sure there is no water or trash in the fuel that comes out. If there is you may need to remove carb and bowl to clean it out. If there isn't any water or dirt in it most likely your gas is ok. Clean and reoil your air filter and make sure the plug is gapped correctly heck even replace it.
If all the above checks out ok and it still does it check the valve adjustment. The 250 and 300 Cats are kind of picky obout their valve adjustments. It is easy to do and just takes about an hour.
Is your dealer Ed? I have always had very good luck with him as well as a lot of my friends that have gone there. If you need any more help just give me a yell and I will have some more stuff to check. It is easiest and cheapest to eliminate the easy free stuff first rather than just throwing parts at it for no reason. Just for kicks and giggles does it still do it when the headlights are on?

 

I have a 99 300 4by4 and can say it has the backfire issue ...but it is mild under hard deceleration....It is a very common issue w/ the 300 and 250 models .I have read that some of the guys have gotten rid of the problem by rejetting or adjusting the needle valve.I havent fooled w/ mine because it starts instantly in all weather and is unusually quick.I love the 300 and i have Honda products also.You may also want to check the choke /enrichener .If the cable is sticking just slightly it will enrichen the fuel mixture without you knowing it.I just went through this problem w/ my 450es.The symtoms were similar to what you are experiencing. Another tip for guys in the colder climates is to keep the tanks full and use a bit of drygas from time to time.Vented fuel tanks will draw moisture into them with the fluctuation in temperature from day to day.It is especially important if the machine sits for long periods of time.A buddy of mine had this problem w/ the 300 cat last winter and we cured it w/ dry gas.You didnt mention if your plugs were fouled or in a lean condition.How many miles on the unit????Is the machine in water constantly???The carburetor is a mikuni i believe and is quite ubitquitous in the ATV industry.How is your ignition system???

 

Go under the search and type in "300" there is a post on the backfireing problem......

 

Thanks for the info so far guys.

mudcat- I am definitely going to try your suggestions as soon as I can. Will probably be friday or saturday. I know for sure the vent from the gas tank is clear. I just checked it the other day. I did not know about the ones on the carb. About the headlights, I never really payed attention. I will be riding it Thursday and Friday without having time to work on it. I will see if their is a difference. All I know it is duck season and I need to get it running good.

mrmom - it does backfire going down hills and etc. That has never really bothered me. It just bothers me when I am going down the road and it backfires, sputters, and cuts out. Plus I am in high gear running half to three quarter thottle and it won't go over 15 w/ huge power loss. It has 700 mi on it and I have had it around water a few time nothing serious. One time it did stall on me, but it was because I got the electrical system wet. After a couple of days of drying out it started and "ran" again. I also performed your search and from what I was reading it sounds like the vents, carb, or maybe just jetting. Also it does not seem isolated to just cold weather.

Here is some more info I thought about last night. I notice (not sure if the choke is on) that during idle small puffs of black (not blue oil) smoke comes out. Kinda smells really rich. Also, a couple of weeks ago. It started to bog down or load up or whatever. I noticed it while manuvering through a woods so we were not running real fast. I put the choke on and it gain a bunch or rpms and hp back after doing that. You could turn the choke off and on and tell a real difference even running at moderate speeds.

Along with what I said I was going to do. This week I am going to get a new air filter and spark plug to put in it. After riding it on Sunday(3-4 days worth of riding) I will put the plug and let you all know what it looks like. I will also let you know what I find on the other things.

Thanks guys

 

I think you should probably start from the begining and spend a few hours and rule out a clogged fuel sytem to start.The fact that the machine suddenly has power when you turn the choke on is classic fuel starvation.The fact that the machine ran well for a short period of time when you first purchased the machine indicates that something has changed and it wasnt a manufactured defect.Remove the tank and clean it, remove the carb and clean it in addition to all the lines. bring the carb in the house and take the bowl off it where you have some proper lighting and and make sure the float articulates freelyand there is no dirt of any kind lodged in it. check the jets or seats for dirt. the jet should unthread.I havent had the carb off mine but a general cleaning can work wonders.also check to make sure the float isnt saturated and keeping it from working properly.I have seen neoprene floats absorb fuel and cease to work.(if it is neoprene).if its a metal float check and see if fuel has leaked into it.Devoid of some engine mecahanical issue ,the 280cc suzuki power plant in the 300 cat is an excellent durable unit.It has been around for years and as reliable as any honda engine.We have a number of them in my sphere of atvers and you cant kill them.The engine in the arctic cat set up is known for carburation issues thoughI havent seen one that wasnt remedied with a jet change or minor adjustment.