still bogging

[afroman]

I took the sled out finally after cleanning the carbs,replacing fuel filter and lines and plugs. the thing still boggs of the line. when I go to take off it boggs out sounds like its going to stall and wont take off. if i feather the throtle she will go take off usually back fire and she's good. this problem is not all the time maybe 60%.

It's an 96 ext 580 (new gas). I've had suggestions to go one jet size smaller, rebuild fuel pump, and check intake. this prob is realy driving me nuts HELP.

comp is good about 110 in each cyl.

[mudslinger64]

it sounds like a throttle saftey switch you might have to replace the washers on your thumb lever,follow the wires under the handle bar pad to the three prong plug unplug it and bend the middle prong up out of the way and plug it back in.then just put your sled on a stand fire it up and see if it helps,good luck.

[BRM]

I have a 99 ZL and had the same problem, it needed new throttle bushings.

[afroman]

stupid question but what are throtle bushings?

[BRM]

They are between the throttle thumb control and the handlebars. Look kind of like nylon washers, and keep the throttle from moving around.

[ChuckN]

Have both carbs been synchronized?

Pull the carbs out of the boots and feather the throttle lightly. Do both carb's slides move up/down simutaniously? If not, adjust the idle screw on one, which ever slide is not moving (turn clockwise) until they both move with the slightest touch of the throttle.

I had a bogging issue at start up on one of my sleds and the belt was the cause. A new belt made a world of difference. Not the backfiring issue though.

I don't think it's the main jet since your issues are at lower RPMs. Only use the proper jet for temp/altitude.

You can try the fuel pump rebuild. That's relatively easy.

[afroman]

I sync'ed the carbs last year and still had the prob. I checked them this year and they both move at the same time. should I try replacing the pilot jets? I'm grasping at straws here i checked the pickup in the tank and it was clean . if it was the safty switch would that not cause it to stall completly or act up at other times? I looked at the bushings and the look OK I guess the throtle seems to move back and forth properly to hit that safty switch( I never knew thats how it worked befor this mistery). Help

[hookem2]

I had the same sled doing the same thing. I found a big mouse nest in the air box by the steering arm

[afroman]

already cleaned up the old mouse nests. thanks anyways.

[VMS]

I am definitely no expert on this stuff, but I am wondering if all you need to to is adjust the fuel mixture needle. I know with outboards (2 stroke) that the needle affects idle roughness and take-off issues. If it is not adjusted correctly, the motor will bog down. Usually the needle needs to be adjust so that it is just a slight tinge rich. Throttle response is much better...

With two carbs, and to keep them as close to sync'ed as possible, adjust both needles the same amount in the same direction.

This should stop your backfire too...

Steve

[hanson]

afroman-

I'm fairly well stumped on this one as well.

Could it be an ignition/timing problem with your sled?

Is it backfiring out of the intake side when it backfires?

When you say the sled is bogging, is it getting too much fuel or not enough fuel?

Do you have a choke cable/plunger getting hung up at all in the carb? Example would be one carb running half or full choked while the other is not?

And a stupid question... Running the right plugs? I'm guessing here that a 580 EXT should be running NGK BR9ES?

I'm just throwing a few ideas out there.

[afroman]

update

I started it and took her for a ride tonight. started excellent better than last year. same bogging problem thou. I found it will ride smooth once I feather the gas to get it going but only up to about 1/4 throtle at about 1/2 throtle that's when she starts spitting and backfireing. I looked at the needle jet and it is not the one listed in my book I think it is a size larger( for a ZR) and it was set on the top grove I lowered the clip to the second fromthe top(raising the needle) to try that. couldn't take it out to try it was to late don't want to [PoorWordUsage] off the wife. will give it a try tommorrow. keep the suggestions comming.

hanson

i think it is backfireing out of the intake side. I don't know if it too much or not enough fuel how would i tell ( I dont want to run it much with the backfiring). and yes i have the right plugs and gaps brand new. i think i might try replacing the plungers after that i think it off to the cat guy this is [PoorWordUsage]ing me off and i have spent like 2000 hours on it I just hate to give in (plus I cant realy aford to pay someone expecaly when i could fix the dam thing if I knew what was wrong).

HELP

[Macgyver55]

Very rarely is a backfire caused by a rich condition. I agree with Mudslinger, it sounds like the throttle safety switch is out of adjustment.

[afroman]

how would I be able to tell if it is and how do I adjust it or can I just disable the stupid thing and how

Thanks

[Gus]

You should be able to just unplug it and see if your problem goes away. My bro in law has a 98ZR and he had the same problem. Unplugging it took the problem away. I would urge you to get it replaced or adjusted if it is truely your problem. The safty switch is in place so if your throttle gets stuck or frozen the machine won't tear off running when you start it. You'll see the tiny flipper or nipple looking thing that get depressed when the throttle is released. Just trace the wires back to where they disconnect and try it out. Remember, it is a safty item so do replace it if it is your problem.

[afroman]

thanks i'll give it a try and let you know

[afroman]

today i'm a happy man . you guys were right from the start it was the throtle safety switch. unplugging the three prong plug kills the engin i guess because it is also conected with the kill switch. but when i started it up disconnected the throtle lever and pressed the switch manually no bogging. so i took the switch out and saw that it comes apart. Well maybe I can clean it I thought to myself. I took it apart (slowly) and the stupid tiny springs inside went flying all over the garage. after looking for about an hour I managed to find them cleaned the switch contacts and put it back together. she works great now. I realy should have tried this from the start but my theory on how it works combined with a lack of knowlege lead to in other directions . Thanks for all the help and I hope this helps someone in the future.

Now to fix the track.

[Captain Ken]

I had the VERY SAME problem with my Artic Cat. Got all of the very same suggestions, EXCEPT for the throttle bushings. It was a combo of the throttle bushings and the wire harness that connects all the safety switches and runs them to the engine - it was kind of oxidized in the main connector. The artic cat dealer in Tower pretty much knew right where to go in order to fix it based on the symptoms I described which were exactly yours including the feathering of the throttle. I also had some bogging when trying to go up steep hills and that was eventually tracked down to a clutch that needed a rebuild. I had bought the sled used from a guy that claimed to have done all the routine maintainance but actually just lied. Now she runs great. Glad you figured it out. Only thing that complicated matters for me was as a result of all the backfiring I broke a reed valve so that cost a couple bucks to fix. Those little jumper deals work real good to help isolate the problem. First thing he did was get down to the first, main one in the engine and jumper that. That basically let the engine run on its own and proved that the carbs were fine, clean, synched, jetted good etc etc and indicated that the problem was in the circuits somewhere.

Have fun!