I seem to have a problem with my '03, 400 4x4.

Sometimes, not often, when I hit the gas hard to get full rpm the motor starts choking out. I don't hammer the gas very often, most of my riding is slow and easy. It started doing this in Sept. I noticed then that gas was running from the overflow on the bottom of the carb. We were on a 4 day hunting trip and had few options. Stripped it down and cleaned the carb. After reassembly, still pouring out. Tore it down again, checked the float valve for wear of tears. It was good so I bent the float tab up a tiny bit. This stopped the gas running out and I had no more trouble.

In early Nov. it turned cold, we were on another hunting trip in the middle of nowhere. My son and I came out of the woods and had about a mile to ride back to camp. It was below freezing and we were in a hurry. We hit a good flat part of the road and I told him to hold on, we're gonna make some time. I floored the gas expecting to take off. Nope, she nearly shut off, spitting and sputtering. I put the choke on full and it came back to life. It ran that way,but not very well, for about a half mile. I tried taking the choke off a few times but it wanted to die right away. Finally about 500 yards from camp I took the choke off and it ran just like new. I had no more problems out of it that weekend.

Today I got it out and rode for a few minutes. I hit the gas and here we go again! As soon as it choked I let off the gas and it evened out and ran fine.

I know its not stale gas. I only have a problem when I floor the throttle. I know if I stay out of the gas it won't act up. Just knowing that it will act up is bugging me. Every time it has happened has been on flat ground and with the exception of today, in the middle of nowhere.

Sorry for the long post. Any ideas?

 

I think I've got the answer. Don't Hunt so Much..! Ha-Ha..Well, if that doesn't set well with ya', try something else. I had a similar problem with my AC snowmobile. I finally took it to the shop and the repair guy said anytime something like this happens, clean the Pilot Jet out, even if it looks like it doesn't need it.

Another thing that can create havoc and is difficult to spot is the gas tank vent hose. If it is plugged, kinked or has any other kind of blockage, it will require the use of the choke. It suffers for air. A new hose fixed a 1-1/2 yr problem for me.

Hope you find it, I know how frustrating it can be to have problems like this.

Good Luck, Happy 2009

 

Don't Hunt so Much..!

That ain't gonna happen! LoL!

I do believe I will pull the carb tomorrow and clean it real good. Did a bit of reading here and it seems that cleaning the pilot is recommended a lot.

 

I thot you'd enjoy the "Don't Hunt So Much". Of course beaing a male myself, I already knew that "It just don't don't work like that".

Anyway, the Pilot Jet problem seems so common with the Suzuki Engine. My carbs are Mikuni. They are great carbs however and as long as you know this is a common problem, it makes life so much easier.

Have a Great 2009.

 

Royz,

I agree with bobpo, "don't hunt so much" you know, cut slowly cut yourself back so you only hunt 7 or 8 days a week and you should be fine.

If that doesn't work clean the carb real good, put some fuel additive in like "seafoam" and I would readjust the float height (since you adjusted it) it should be 17mm (0.7inches). Manual says you should have a 150 main jet, 38 slow jet, 2 1/8 turns out of the low speed fuel screw. Clean the choke plunger as it may not be closing/opening totally. It is an enriching system and it can get gunked up and stick.

When I clean my carb I spray carb cleaner in every hole I can find and make sure it sprays out some place. I then blow compressed air through all the holes as well just to be sure. Watch your eyes so nothing sprays back into them. Put it all back together and you should be good to go.

This has been an ongoing problem for every ATV I know. I guess it is the price we pay to have to play. I know a guy who even with an inline filter has had nothing but trouble with this on his EFI machine. He is so tired of dealing with it that he is trying to sell it. However, I just replaced the fuel lines for him and he has not had it occur since. We chose to do this on a hunch and when we cut the fuel lines open we discovered that the lining on the inside of the hose was disolving and clogging stuff up.

I have had better luck using Seafoam in every tank of gas in my ATV.

Swampy

 

I appreciate all the help guys. I just got it back together and it seems to run better. Seemed like it had more power at takeoff and didn't choke at all.

I don't have a manual for it so I don't know what all the parts technical names are. I pulled the bowl off and removed the two brass screw in "things" right in front of the float valve. They didn't seem to be dirty but I soaked em and blew em out anyway. There is a screw on the bottom front center of the carb that is outside the bowl. I removed it, the spring and washer. It was filthy so I soaked and cleaned it. Then I blew the whole carb out with compressed air, put it back together and took it for a spin.

Swampy, ever since I noticed the quality of gas declining I have kept Sta-bil and Marvel Mystery oil mixed in my gas. The only thing I noticed being gunked up was the screw on the front of the carb. That is the only thing I didn't take out when it gave me trouble before.

Again, thanks for the help guys.

 

As Swampyjunior said, that screw is your slow speed pilot screw and should be adjusted 2 1/8 turns out. I had a problem with mine as it would not come out. I had to drill and use an easy out to get it out. Then to my surprize, when I tried to find a tap to clean up the threads, they were 6mm x .75 which is not common. I had to special order the tap from a machine company which cost $6.80. Shipping was more. Good luck.