1996 XLT trouble running, need help - Snowmobile Forum: Your #1 Snowmobile Forum

Smackhq · 10-25-2009, 12:41 PM

Hello All,

Need some assistance or guidance on 1996 Polaris XLT that was given to me.
First off let me state that I'm really new to snowmobiles so forgive me if I ask some crazy rookie question. ;-)

Anyways, onto the sled. The previous owner stated it worked great for years but has sat a long time. I started it with choke and it did run but not well at all and stumbled along until it coughed a few times out pipe and stalled.
I pulled the plugs to get a general idea of what was going on and found all 3 very fouled. They were BR9ES which I think is incorrect for that sled according to what I have found on net.

Just wondering where you guys would go from here if this sled was yours other than maybe the obvious on getting correct plugs.

The engine is model EC58PL07 Indy XLT RMK with ACCS.

Here is a partial list of what I think I should check but please comment:
1. replace plugs
2. check jetting needles: main and pilot
- what is pilot screw setting for these sleds?
3. airbox check and maybe the ACCS (which I think is just a fancy system to auto adjust the carbs for altitude??)
4. check ignition system.
5. choke system / adjustment?

Any tips would be appreciated. Btw, fuel is new and oil topped off.

How hard is it to pull the carbs, clean, reinstall and sync?

Thanks gang!

Rob

IRONDOG · 10-25-2009, 03:12 PM

Very first thing before you even consider anything else is a compression check with a good gauge. If the clutch side cylinder is low or no compression you may have a bad crank (pto bearings and crank end shot). This is the #1 problem with that engine- they all go sooner or later.
Jerry

TwinsofMLB · 10-25-2009, 03:16 PM

Clean the carbs first before you go any further.

Disassembly and Cleaning of a Mikuni Round slide Carburetor

Whatever you have for plugs in it right now, get the same ones. Inspect all of the lines and make sure that the fuel filters aren't clogged. Do that and see how it works out.

Smackhq · 10-25-2009, 04:51 PM

Thanks for help.

Well pleased to report that compression is as follows (unless these are bad numbers):
cyl 1 (left facing sled, chain side): 114
cyl 2 middle: 115
cyl 3 (right facing sled): 115

Cleaning carbs seems like kind of a long process so I'm hoping to leave that till end but I'm sure I need to go there. I haven't checked out the link above on the carbs but just in general is pulling and cleaning the 3 very hard? How long?
How about syncing them back up? How tough is that?

Can the ACCS system screw things up?

Also need to add that previous owner reported that he thought middle cylinder was hot or overheating.
When I started it last I did note that it felt like it was not running on all cylinders.

TwinsofMLB · 10-25-2009, 06:22 PM

It's the most basic and simple job that needs to be done every year in my opinion. After the first time, you'll be able to teach it to a 5 year old. My first time was pretty difficult because I knew nothing about what was in front of me but that link that SEG originally showed me made it pretty easy. It would take me a total of about 20 minutes to clean and sync my carbs now. Pretty simple: just take the airbox off, shut off the fuel valves, remove the lines going to the carb, unscrew the top, and take it to a good work space. After that just follow the steps to dissasemble + clean from the link and put them back on.

To sync them is way easier, there's one screw that needs adjusting but it needs to be done in cold weather.

mrholmquist · 10-25-2009, 09:09 PM

To sync them is way easier, there's one screw that needs adjusting but it needs to be done in cold weather.[/quote]

Huh?????

Not sure what one screw you mean.......

The process of syncing carbs is done to ensure all cylinders are contributing equal power by adjusting all the throttle cables to lift the slides equally.It needs to be done periodically to compensate for the cables stretching as they may stretch at different rates . This would allow one or more carb not to be open as wide as the others at a given throttle position.

It is best done using mercury sticks or a uni sync tool which measure the volume of air flowing through the individual carbs while the engine is running. The adjustment can also be acceptably done with drill bits of specific sizes although this method is not as accurate. Once the carbs are all synced at part throttle the carbs can be synced at idle using the throttle stop screws
on all carbs.

The first step adjsuting the cables to sync the carbs with the throttles partly applied is by far the most important part to ensure smooth running and maximum engine performance.

The idle adjustment will help idle quality and throttle response on takeoff but lets face it we don't drive our sleds at idle.

Smackhq · 10-25-2009, 09:40 PM

Is that compression I listed ok? 115 pretty much in each cylinder.

Polaris87 · 10-25-2009, 09:43 PM

yep that sounds good. Anything less than 100 is unexceptable.

TwinsofMLB · 10-26-2009, 09:45 AM

Compression's good, the screw is on the opposite side of the clutch on the carb, it takes a flat screwdriver head.

mrholmquist · 10-26-2009, 09:53 AM

Quote:

Originally Posted by TwinsofMLB

Compression's good, the screw is on the opposite side of the clutch on the carb, it takes a flat screwdriver head.

The screw you are talking about is the idle mixture screw. It is NOT used to sync the carbs . Get yourself a manual and read up on the proper procedure to sync carbs .....you will be amazed how much better your sled will perform if the carbs are in sync

TwinsofMLB · 10-26-2009, 10:07 AM

nope idle screw takes a phillips head and it's on the clutch side. Air bleed screws take flat.

mrholmquist · 10-26-2009, 10:28 AM

Quote:

Originally Posted by TwinsofMLB

nope idle screw takes a phillips head and it's on the clutch side. Air bleed screws take flat.

The air bleed (flat ) IS the idle mixture screw. And once again it is not used to sync the carbs.
Turn it in and you get less air or in other words a richer mixture during idle operation. As you turn it out it will cause the opposite effect to the idle mixture. It does not effect high speed operation.

The idle stop screw (phillips) is used to set the position the slides will drop to when the throttle is released.
This in turn will control idle speed.

TwinsofMLB · 10-26-2009, 11:15 AM

If the air bleed screws are at a different setting, your carbs are not in sync. If they are the same, then that's one step out of the way. The other is for gas. Each screw is half of the process.

mrholmquist · 10-26-2009, 12:05 PM

No bud you are not catching the play....... True the air bleed screws should be adjusted the same but that is definitely not syncing the carbs. There are different adjustments which need to be done.

I will scan some pages from the shop manual and send them along later today.

Smackhq · 10-26-2009, 04:15 PM

No worries, I get what both of your are trying to say. I found the shop manual online and it has helped clear up a few things and is definitely worth the investment. I'm going to pull and clean the carbs thoroughly this weekend and set them all to stock settings and go from there. Since the main jets are easy to get to I checked those and they are stock so I assume the pilot is same but maybe dirty. This little girl has been sitting for some time, just needs some love.

Sounds like syncing the carbs without the correct tool can be troublesome. Is the Uni Sync tool hard to use (laymen here remember...) and worth the investment?

TwinsofMLB · 10-26-2009, 04:23 PM

Never had to fool around with anything other than those two screws... don't know for sure. Anyway mrholm, I know what you're saying, that's partially what I was getting at. The first step is usually the air bleed screws so I listed that first

mrholmquist · 10-26-2009, 04:55 PM

the pilot air screws really has nothing to do with syncronizing the throttle slides and they should be adjusted to whatever amount of turns out the manual or the hood sticker specifies for the model sled in question.

When you syncronize the carburetors what you are trying to acheive is to make all the slides working in unison. Or in other words at any given throttle position all the carbs will be open the same amount. Which will allow each individual cylinder to contribute equally for power output.

This will have a huge effect on engine performance.

If the carbs are out of sync some of the cylinders will be working harder than others and the weak cylinders will be lagging back robbing power.

TwinsofMLB if you have not ever properly syncronized your carbs chances are your sled is not performing to it's potential.
Since the slides are actuated by individual throttle cables it is actually the cables that you adjust to sync the carbs. You have to make the adjustment at part throttle when the cables are actuating the slides.

The other part fo syncronizing is to adjust the slides so that they are at exactly the same height when the throttle is released and the cables are slack. This is done using the idle stop screws which stop the slides from closing completely when the throttle is released. By adjusting the idle stops you are controlling how far down the slides will drop when the throttle is released . Here are some links to pages from the factory repair manual as promised.

pilot air screw
Snowmobile Fanatics

carburetor syncronizing procedure page 1
Snowmobile Fanatics

carburetor syncronizing procedure page 2
Snowmobile Fanatics

The uni sync tool is a little tricky to use at first. I much prefer to use the mercury sticks. Especially on three or more cylinder engines. The reason being that you can watch all the carbs at the same time . The uni sync requires you go back and forth between the carbs , take a reading make an adjustment repeat bla...bla..can be a pain on a three cyl . There are people who have made their carb syncronizer tools themselves at home sometimes using less dangerous liquids than mercury.

Motion Pro SyncPro Carburetor Tuner - DennisKirk.com

I tried to download the images to my gallery on this forum but they would not load

jKsled · 10-26-2009, 05:11 PM

when i sync my carbs i just reach in and use my fingers to make sure theyre even. i check at idle, half, and full throttle positions. you can feel if there is any difference, and then adjust from there. it might not be exactly perfect but it has always worked well, and i can get them very very close that way....

TwinsofMLB · 10-26-2009, 05:27 PM

Wow I never knew that... thanks holm.

mrholmquist · 10-26-2009, 05:29 PM

Quote:

Originally Posted by jKsled

when i sync my carbs i just reach in and use my fingers to make sure theyre even. i check at idle, half, and full throttle positions. you can feel if there is any difference, and then adjust from there. it might not be exactly perfect but it has always worked well, and i can get them very very close that way....

Actually that is how some of the pros do it too. It is not near as accurate as using the tool but definitely better than nothing. Requires you have a good feel for it or you will mess it up maybe worse than if you didnt touch it.

Better still is to use the drill bit method which is also laid out in the manual. In essence you use the shank end of a drill bit like a feeler blade to compare the height of the slides much in the same way you are doing it with your fingers. I will see if I can find the sheets on the drill bit method and post them.