04 800 "pops" and sometimes dies against closed throttle

[RetFire]

Howdy. I am new here, think I dumped my intro so please bear with me.
My 04 800 159 runs extremely well under power. Has never failed me on a climb or on the trail. Problem comes against a closed throttle. When coming off a steep climb it will start to pop and the tach will drop off unless I feather the throttle. When I get back on the flat I have to keep feathering until I get it to idle. At that point it may stay running fine or after a short while will suddenly die. Starts up immediately after with a quick pull on the rope. Also, after a run down the trail, when I come to a stop the engine will pop as it idles down. When it does the tach dives off. Again I can feather it down and it may hold or it may not. Has never overheated and the plugs show I'm running a little fat but does not load up. Altitued doesn't seem to make a lot of difference. Would appreciate any thoughts

 

[bigdan743]

800 pops

From your description, I be concerned about idle mixture to lean. The carbs should have mixture control screw and an air screw. I think the air screw should be backed out about 1 1/8 turns and the mixture screw I set to get max rpm at idle. Than you need to check the oil pump adjustment and the throttle free play on the throttle lever per the service manual.

 

[theultrarider]

Yep, sounds like you are just a touch lean on the idle circut. There are both fuel screws and air screws that can be adjusted on those to get it fine tuned. Unless you are real comfortable with messing with it, you are probably better off paying 1 hour of labor at a shop you trust to set it up right and be done with it. Should be no parts, just an hour of shop time.

 

[RetFire]

Thanks much. With the color of the plugs I was thinking I may be too rich. I get around a shop pretty well but not with 2 cycles and especially adjusting and balancing carbs. Will definately get it to the shop.

 

[m8magicandmystery]

throttle safety switch adjustment..??...did you try it with the bypass plug in...??

 

[theultrarider]

Thanks much. With the color of the plugs I was thinking I may be too rich. I get around a shop pretty well but not with 2 cycles and especially adjusting and balancing carbs. Will definately get it to the shop.

Ya, it's not rocket science, but for someone used to dealing with them, it will only take a few minutes. If not, you can chase your tail in circles.

 

[RetFire]

Thanks once again for the responses. I know where the throttle switch is and even how to adjust it. I am not sure about a bypass plug for it though. Would that be something in the repair manual?

 

[m8magicandmystery]

you should have a two prong plug that heads up to your throttle block..usually a few inches below the handle bars on the post.. and the bypass plug is usually in the tool kit...if you don;t have the bypass plug you can just seperate the machine plug and loop the downstream side with a temp wire...your sled is suppose to shut off if a cable is stuck/frayed/frozen..sometime the switch malfunctions and thats why they have the bypass plug in the tool kit..

 

[m8magicandmystery]

i think its a two prong plug..??..

 

[m8magicandmystery]

willikers...i thought this thread was in the cat section..but maybe its the same as the cat 800...it should be...

 

[theultrarider]

m8 may be right. How much free play is there in your throttle lever? If it is too loose, that is exactly how it would act. Tighten up your throttle cable so you have just a hair of free play. Like m8 was also trying to get at, on a polaris, if you just plain unplug all the electrical wires going up to the throttle block, that will disable the kill switch, and the stuck throttle safety switch. Don't ride it other than to test it this way!!! Good luck.

 

[RetFire]

May be on to something. There does seem to be a bit of slop in the lever. Will take a look at it tomorrow. Would be great if it is that simple. And again I thank all of you for your input.