'89 Polaris longtrack won't start

[Canadian_bacon]

Hi all, I have an '89 Polaris longtrack 432cc snowmobile that I can't get running. I started it two days ago by dropping fresh gas into the cylinders through the spark plug ports. It would start and quit several times until I was able to keep it running by holding the throttle down halfway. If I gave it more gas it would bog and if I let off it wanted to stall. I pulled the carb apart and cleaned it today and tried to start it again the same way. I can't understand why it won't burp even when putting gas in the cylinders. I checked and still have spark. The oil injection system was removed several years ago and the gas has been mixed since. I "think" it is a 50:1 mix (that's what I mixed anyway) but can't remember for sure...(it may have been 70:1). Even if there is an issue with the carb, it should still want to fire on the mixed gas I poured into the cylinder. Any ideas as to why it's not?? In my world, spark + fresh gas = running.

 

[007sevens]

Hi all, I have an '89 Polaris longtrack 432cc snowmobile that I can't get running. I started it two days ago by dropping fresh gas into the cylinders through the spark plug ports. It would start and quit several times until I was able to keep it running by holding the throttle down halfway. If I gave it more gas it would bog and if I let off it wanted to stall. I pulled the carb apart and cleaned it today and tried to start it again the same way. I can't understand why it won't burp even when putting gas in the cylinders. I checked and still have spark. The oil injection system was removed several years ago and the gas has been mixed since. I "think" it is a 50:1 mix (that's what I mixed anyway) but can't remember for sure...(it may have been 70:1). Even if there is an issue with the carb, it should still want to fire on the mixed gas I poured into the cylinder. Any ideas as to why it's not?? In my world, spark + fresh gas = running.

Sounds to me like carb issues.

When you cleaned the carbs did you inspect the idle jet. Its the tiny jet way down in that little hole that is extremely hard to get out without a proper flat head screwdriver. Chances are it is plugged. The main jet is easy to get at and should be pulled out and cleaned. After taking the float out and removing the needle valve. I use a blow gun and check all the ports by blowing compressed air through them. When you reinstall the float check that it is level. With the carb upside down and the float and needle valve installed the float should be level with the mounting face where the bowl would mount. When you have this all done check that the needle valve seats. you can use a vacuum pump if you have one or simply a hose and your tongue as the seal. It should hold a couple pounds of vacuum. If it doesn't the carbs will over fill with fuel and run out the over fill tube. New needle valves are cheap. Make sure carb boots are not cracked. Lastly the fuel pump could be stuck if it has sat for a long period with fuel in it. When it dries up it can leave the petals stuck in the pump. If you suspect this to be the problem as simple way to check is to make a fuel can and gravity feed the carbs by having a can high then the carb or by adding pressure to the fuel tank to force fuel through the pump while you pull it over. A rag and and blow gun in the fuel cap opening works well..

I attached a PDF file on those engines. Not that it offers a lot of trouble shooting but maybe something in there helps. http://www.vintagesnow.com/Polaris_files/85 engines.pdf

 

[retiredpop]

Hi all, I have an '89 Polaris longtrack 432cc snowmobile that I can't get running. I started it two days ago by dropping fresh gas into the cylinders through the spark plug ports. It would start and quit several times until I was able to keep it running by holding the throttle down halfway. If I gave it more gas it would bog and if I let off it wanted to stall. I pulled the carb apart and cleaned it today and tried to start it again the same way. I can't understand why it won't burp even when putting gas in the cylinders. I checked and still have spark. The oil injection system was removed several years ago and the gas has been mixed since. I "think" it is a 50:1 mix (that's what I mixed anyway) but can't remember for sure...(it may have been 70:1). Even if there is an issue with the carb, it should still want to fire on the mixed gas I poured into the cylinder. Any ideas as to why it's not?? In my world, spark + fresh gas = running.

Depends how much gas you poured in there. You may have flooded it with too much gas. How is the compression? Without good compression they can be a bugger to start. Crankcase seals could be leaking too and sucking in air.

 

[Canadian_bacon]

Thanks for all that info. Yes I checked the idle jet, main and pilot. They were alittle dirty so I cleaned them with carb clean, Q-tips and compressed air. I haven't looked at the pump but maybe that's the issue. I was just curious why it worked pouring gas into the cylinders yesterday but not today. I would think I should still hear it burn off the fuel I put in the cylinders if I had spark, which I do. Weird.

 

[Canadian_bacon]

Ya, I was going to check compression tomorrow. It just seems like it should be something simple cause it would at least fire 2 days ago and now nothing. Doesn't even sound like it wants to catch. Maybe now that the carb is cleaned up I flossed it by over priming it.

 

[007sevens]

Thanks for all that info. Yes I checked the idle jet, main and pilot. They were alittle dirty so I cleaned them with carb clean, Q-tips and compressed air. I haven't looked at the pump but maybe that's the issue. I was just curious why it worked pouring gas into the cylinders yesterday but not today. I would think I should still hear it burn off the fuel I put in the cylinders if I had spark, which I do. Weird.

I would say its flooded. if you pull the plugs and rotate the engine a few times and get fresh air in there it may fire. Remember a two stroke engine takes gas to the crank case and brings it to the top of the cylinders. It may have a bunch of gas in the case.

 

[Canadian_bacon]

Ya, I'll put in some fresh plugs tomorrow to and see if that makes a difference. Perhaps it's a combination of flooded and weak spark.

 

[moyiesledhead]

If your float bowl inlet needle didn't seat properly when you put the carb back on it's probably siphoned most of your fuel tank into the crankcase by now. Do you have a fuel shutoff? If so turn it off, pull the plugs, and wait a few days then try it. I had one of those years ago, but I can't remember if there's drain plugs on the crankcase. If there, pull them out and see if any gas runs out.

 

[Canadian_bacon]

Huh, interesting. I never thought of that, I'll look into that, thanks

 

[007sevens]

Huh, interesting. I never thought of that, I'll look into that, thanks

Had more than a few sleds come in to the shop in Nov. people complaining it won't start. Pull the plugs from the cases and and drained out a soup can from each cylinder.

 

[Canadian_bacon]

Thanks everyone for your help, I found the problem. Compression is 120/60.

 

[CatMan16]

Thanks everyone for your help, I found the problem. Compression is 120/60.

That would be pretty good if you were talking blood pressure. Not so good for compression though.

 

[Hansen13]

Yup that sounds like a problem lol


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