bushboy

A few wonths ago i baught the sled and needed an engine rebuild after the previous owner blew the engine. Pulled and cleaned the carbs 3 or more times, changed the spark plugs a bunch of times, opened the gas pump 2 times and everything looks fine. It will only move if the choke is on and if i leave it on for more then about 10 second it stalls and if im moving with the choke after a few meeters that its on it slows down and iddles. It backfires sometimes as im cranking it. Anyone know whats wrong???

scrammy650

welcome to the forum

mtwi

Welcome to the forum.

There are a lot of things that could be wrong.

First, did you rebuild it yourself? Have a shop do it? Previous owner rebuild it?

I have seen a little about XLT's twisting the cranks, the crank could be out of phase, are all the wires hooked up correctly for the ignition?

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Mike

1997 Polaris Ultra-- 121 Ripsaw track Powermadd pivot adapter and 4" block

1997 Polaris XLT Special--All stock(wife's sled)


1994 Arctic Cat ZR 580--The back up machine

2010-2011 miles: 425

2011-2012 miles: 278

POL3INAROW

Sounds like carbs are out of adjustment. If it will only get moving on choke and then it is fine after your moving with choke off. it is probably lean on the idle circuit/pilot jet. Does it rev up with track off the ground? If so you can adjust air bleed screws, go in all the way lightly and then turn out 1 1/2 turns. This should run the sled. also you have to adjust all three carbs equally for correct idle speed. If you buy a manual it will explain how to set them up. Follow it closely and do not skip, this is important for three carbs to work correctly. If it runs better but still not without choke, start checking for air leaks. With it running, spray carb cleaner around pto seal, carb boots, and case seal. If RPM picks up with spray you have an air leak in that area.

bushboy

I tried adjusting the screw but it still bogs when i push the throttle, it bogs the less when i adjusted the screw at one turn, i adjusted the needle jet to the middle notch instead of the second from the topand still bogs. What else should i try could it be thee needle jet?

TwinsofMLB

Sounds as simple as poor spark to me. Change the plugs, ground them to the engine, pull it over, and look for a solid blue spark.

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1992 Ski doo mach 1 617cc (the beast)

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bushboy

The spark is good, the mixture screw is completely shut witch makes it richer, the owner manual says that if it backfires its too lean and i tried the needle at the second notch from the bottom. It idles perfect but sometimes it goes up for a bit and then goes back down.

xflyer53

I think a little better understanding of how the carb works is in order here. The needle jet/ jet needle have nothing to do with the idle.

This link may help you---> http://www.mikuni.com/pdf/vmmanual.pdf

If it is a carb issue, I would confirm jet sizes, make sure they are perfectly clean or new, reassemble, and properly sync them.

The standard XLT came with 210 main, 35 pilot with 1 turn on the air screw.

__________________
'92 Indy 650
'95 Indy XLT 600, plastic skis, skid plate, cobra windshield, XTRA 10, 1" riser

bushboy

yes but the main problem is when i give gas it idles almost perfect. One of the carb boots are flexible and when i give gas it completely bogs and looks like air is pushing the carb out away from the engine as if air would be coming out were its supposed going in, when i let go of the gas it picks back up and returns to idle. I will try the screw at one turn again, does the jet needle have anything to do with when i try to move forward with the machine at about 1/4 throttle?

RJ Gleason

You might want to check out the reeds, could be cracked or chipped.

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'93 Wildcat 700EFI
w/ Comet 108 Pro-4 clutch & 01 ZR skid

'90 Wildcat Project in progress.

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1980 Indy Trail 440 (for sale)
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bushboy

are you sure there are reeds i read in another forum that its a piston port engine and has no reeds

BC_Dan

You are right, the xlt engine didnt' have reeds.

The jet needle/needle jet assembly doesn't start metering fuel to about 1/4 throttle, so your problem should be in the idle circuit. I would go back and clean the carbs again, paying special attention to the air and fuel passages to the pilot jet and to the pilot jet itself. Try poking a soft wire (one strand of phone line works great) through all the holes to see if you can dislodge any varnish or debris. If you have spotlessly clean passages and pilot jets and the hesitation and bog persists even with the air screws all the way in, go up one size on the pilot jet.

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2007 Dragon RMK 700 155", 2008 RMK 600 155", 2006 RMK 600 144", 95 Prowler 550 2-up, 1990 Indy 650, Really OLD Cat Cheetah

RIP, destroyed by fire 1-22-2008
04 RMK 800, 05 RMK 600, 02 RMK 800, 97 RMK 700

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bushboy

I did clean the fuel passages with a wire and after putting it back together i saw with a flashlight that there was a CDI cable stuck under the oil pump lever and it only moved from half way to full opened, now it runs enough to actually ride and the mixture screw is at 1/2 a turn. It now runs good but I still get the rare bog and i am hoping that it might just be some old fuel because it was parked for a while. Thanks allot for the tips