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Discussion Starter #41
That would be most likely a clogged pilot jet.
Easy test; when you hit that range, flip the choke on briefly. If the bog goes away, it is carb related. If not, then a clutch cleaning is in order.
 

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Sledaholic
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That would be most likely a clogged pilot jet.
Easy test; when you hit that range, flip the choke on briefly. If the bog goes away, it is carb related. If not, then a clutch cleaning is in order.
Correct me if I'm wrong but - Pilot circuit runs- idle to roughly 1/4 throttle-then- the slides needles take over from 1/4 to roughly 1/2-3/4's then once the needles are up and out of the mains orifice then its running on the mains right out to full throttle. So if his sled is dead at 1/4 to 1/2 throttle or so it could be that while playing with carb he might of changed clip position/the last person playing with the carbs could of or reassembled them wrong, OR he could have the floats adj. wrong. Plus he should for no reason I can think of have 2 different size mains. It sound like to me that somebody at one time was messing around with those carbs and lost a jet or something. I would say that a PROPER, FULL cleaning and float adjustment & needle adjustment with the MATCHED set of mains is in order no matter what he finds, that is if he plans on really riding that sled anywhere away from home.
 

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97 formula 500

ok...after doing some research on this sled the jetting mag is 290 and the PTO is 310...Sitting on the sled which carb goes left or right? I bought this used and have been putting them on the way it came but I don't know if its correct??? also anyone know what the float numbers mean and are they suppose to be the same on both carbs??? Thanks for any help
 

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Sledaholic
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Pto is clutch side. i would think that both carbs floats would be the same, but also keep in mind that sometimes parts are superseded with new numbers though I would certainly make it a priority to find that out.
 

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Thank you mainesled...I've never heard of two different size main jets before
Yeah thats a weird one, I know that the mid to late 80's Polaris triples guys ran the center cyl. richer because the cyl ran hotter then the PTO & Mag cyl's but after looking at the parts list for your sled its a factory thing.

Main Jet MJ 310 (PTO) Formula 500. Formula 500 Deluxe.(Clutch Side)
Main Jet MJ 290 (MAG) Formula 500. Formula 500 Deluxe.(Pull Start Side)

Keep us posted as to what your doing & find.
 

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I took the fuel pump off and checked it..found nothing, so I tested it and there is no fuel coming in to the pulse line so that's one thing out of the picture...I don't have a manual so I don't know how to adjust the floats. The floats sit on little rods and ride up and down fine with a plastic cap at the top of the rods...I don't see how you can adjust them unless you adjust something else:dunno:
 

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starting issue

I have an 2006 mxzx 800 ho and when starting the sled cold it fires on one or two pulls and runs great...but after its hot and i shut it off...doesnt want to start again. any suggestions on what to do?
 

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I have an 2006 mxzx 800 ho and when starting the sled cold it fires on one or two pulls and runs great...but after its hot and i shut it off...doesnt want to start again. any suggestions on what to do?
If you give it just a tiny tad of throttle while pulling it should start on second pull. Turn off carb heaters and leave off MIGHT help a bit but on that motor it seem as though its just the nature of the beast from my experience, just a SMALL amount of throttle and on second pull while holding throttle is how most of them start unless you have elec. start.
 

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I took the fuel pump off and checked it..found nothing, so I tested it and there is no fuel coming in to the pulse line so that's one thing out of the picture...I don't have a manual so I don't know how to adjust the floats. The floats sit on little rods and ride up and down fine with a plastic cap at the top of the rods...I don't see how you can adjust them unless you adjust something else:dunno:
You have to bend them to adjust--when carbs are upside down the floats should be level
 

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THanks Main sled...not sure how to turn off carb heaters...didnt even realize i had carb heaters? thanks for your help
 

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THanks Main sled...not sure how to turn off carb heaters...didnt even realize i had carb heaters? thanks for your help
Open left side panel and look at pto/clutch side head and you'll see a black hose just above it leading to carbs with a red little knob-knob turns heaters off & on--lets coolant flow once T Stat is open and anti freeze is hot.
 

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Problem Starting

Hi, I'm new to SkiDoos. I have a Lynx GLX5900 and I just can't get it started.
The plugs are wet after a few pulls on the start cord and they are sparking (not sure when under compression). Should I be using the choke, openning the throttle? Any ideas?
Also, I have no manual and can't seem to find one either here or elsewhere online. The battery is dead but there is a jump cable with it. It has standard croc clips on one side but a special connector on the other. I've looked around under the hood and can't find where to connect it. It would be handy to use the starter motor as I was pulling the starter cord for a couple of hours today!
cheers, Arch
 

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quote

Mr. Gleason, I do appreciate your help regarding sleds but I have a problem with your quote. Is it neccessary to put that at the bottom of every thread? I am a Christian and I hope you are one also. I find it offensive to have to read that quote every time I read one of your helps. Seeing it so often it almost burns a picture in your brain and you see it immediatlly on viewing your help. Wether you type the full word or * it as you do it is still there. As much as I appreciate your help I will have to pass your threads by if you continue to post that quote. I am sure with your intelligence you can come up with a far more appropiate quote. Like " Have a good God week snowmobilers. Stay Safe.
sorry but Blessings and cursings should not come out of the same mouth.

dajcat
 

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84 440 Polaris

Mr. Gleason, After reading your piece on Mikuni Carbs I realize that my sled has been put together piece meal. my on off switch is the safety switch (no key start) oil injection has been removed and orifices plugged, injector pump cable disconnected. How can i tell wether i have that warmer for the carb.? What does it look like.? At the fire wall there is a black box with a hole in the side with a flex pipe that goes up and into a round air filter.
Also i don't understand what you mean by "you flip the switch, open it wide and (hands off the throttle) to start.
You sent me an email saying the pump may have a leak in it. i take it you are talking about the fuel pump fastened to the sled deck.
Yesterday I tried all day to start with no sucess. This morning i went out and first pull away she went. Took it for a spin (about 15 minutes) with just enough time to get in under the shelter. She died on me and that was it for the day. Any help will be appreciated. When she runs she is fast. I am considering putting all the oil injection system back on the sled if you think it will help. When it first fires with an injection system are you firing pure gas?
I wonder if this engine was not made for mixing the fuel 50/1.
 
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