Author Topic: Snowmobile Leaking Gas (Read 2775 times)

bassin212 · « **on:** Jan 21, 2019, 02:52 PM »

Hey Everyone. So I just bought a snowmobile and of course, it needs some work and not exactly what I thought. Anyways, I checked the sled and i'm fairly certain I never saw any leaking gas. As it ran I looked at the carbs, exhaust, belt etc. didn't see anything. Anyways the next day I showed up with the trailer. Started it and drove it on. On my way home I had to fill up my truck and figured I'd go ahead and fill the snowmobile tank as well. The snowmobile has been sitting on my trailer and I haven't started it since Friday, 1/18/19. I checked on it today 1/21/19 and noticed yellow snow.....a lot of it... I tracked it and noticed that it was dripping gas. which was weird because it hadn't been running. I wanted to see if it would start and it did and it runs fine but is just leaking gas. I noticed one of the carbs is dripping from the overflow.

Doing some research, it looks like I just have to clean the carb and the needle and seats? anyone have experience with this type of situation? It just seems weird to me it would start leaking after filling it up and not running.

river_scum · « **Reply #1 on:** Jan 21, 2019, 02:57 PM »

yeah most likely the float or needle valve. print off a schematic and rebuild the carb/s. you can install a shut off on the gas line too, if it dosnt have one already.

jethro · « **Reply #2 on:** Jan 21, 2019, 03:00 PM »

Leaking gas on a sled that hasn't run for a long time is often the float bowl valve (especially at the overflow). Once you start running gas in the carbs it can dislodge grit in the fuel system which blocks the tiny needle valve that is for the float valve. Any cleaning of the carbs should include cleaning and possibly even replacing the float bowl valve.

eriksat1 · « **Reply #3 on:** Jan 21, 2019, 03:02 PM »

Install a gas shut off valve between the tank and carbs. I have had them randomly leak gas also when parked a long time. If the carb needle and seat leaks it will drip out the exhaust pipe coming out of the cylinder. And be hard starting (flooded). get your needle and seats replaced on the carbs. and make sure to get the good ones not the cheapest ones.

Jkoht · « **Reply #4 on:** Jan 21, 2019, 03:05 PM »

If you're not mechanically inclined to clean and rebuild a carb, I'd suggest running a bunch of seafoam through the engine. Many times I've fixed a sticky carb with this method. Otherwise find a mechanic.

jethro · « **Reply #5 on:** Jan 21, 2019, 03:08 PM »

I know the sled, it should have an inline fuel shutoff factory installed. Most Cats of that era did unless someone changed it up.

bassin212 · « **Reply #6 on:** Jan 21, 2019, 03:11 PM »

it did, but the previous owner put new fuel lines in it and by passed the shut off. for some reason the shut off was at the top of the tank. I've cleaned carbs before and luckily only one is leaking. I'll prob drop some seafoam and ethanol treater in it and run it for a while and see what that does. then i'll clean the carb after.

DR.SPECKLER · « **Reply #7 on:** Jan 21, 2019, 04:54 PM »

Tap on the float bowl on the carb thats leaking.floats probably stuck down letting gas flow out the needle jet the whole time.if that trick doesn’t work pull bowl and spray with carb cleaner.

bassin212 · « **Reply #8 on:** Jan 21, 2019, 05:23 PM »

maybe the 1.5 hour trailer ride it bounced around and got stuck. Hopefully it's just sticking and I just have to clean it.

Yukoner · « **Reply #9 on:** Jan 21, 2019, 06:16 PM »

Seafoam is your friend, especially after sitting for so long, but be sure not to overdo it.

A little does an amazing job!

Ted

tipman14 · « **Reply #10 on:** Jan 21, 2019, 06:28 PM »

I would think about reinstalling inline fuel shut off valve for traveling purposes.

A man called horse · « **Reply #11 on:** Jan 21, 2019, 06:35 PM »

Most likely you can thank the government. Alcohol in our gas attracts water. If left for “any” time the alcohol in the bowls and the tank evaps & leaves the water. You have the end result, but your now eco friendly & supporting the use of our food resources to screw up all small engines.

bassin212 · « **Reply #12 on:** Jan 21, 2019, 06:42 PM »

So I took the leaking carb off. in the pictures below you'll see me pointing to an overflow fuel line that has a cap on the end. I noticed that cap was very lose and actually dripping gas. So once I removed the fuel line from the carb, it obviously stopped leaking, but if the fuel line was pointed down it would leak. So, with that hose having a lose cap were the floats just not getting lifted up by the gas in the bowl to properly work? I also attached some pictures. The carb looked really clean, does that seat and needle look to be at the correct angle?

Anyways thanks for your help everyone! really hoping it's as easy as just fixing that leaking cap at the bottom of the carb bowl.

meandcuznalfy · « **Reply #13 on:** Jan 21, 2019, 07:26 PM »

Does needle valve close when the float hits it

bassin212 · « **Reply #14 on:** Jan 21, 2019, 07:32 PM »

might be a dumb question, but how can you tell?

meandcuznalfy · « **Reply #15 on:** Jan 21, 2019, 07:34 PM »

Push on float should be able to see needle valve going down.

meandcuznalfy · « **Reply #16 on:** Jan 21, 2019, 07:37 PM »

Might have to hold carb as it actually sits and push up on float to see it.

bassin212 · « **Reply #17 on:** Jan 21, 2019, 07:41 PM »

when you say push on float, do you mean the metal/brass looking U shaped piece that sits on top of the Needle Valve? If so, yes it pushes down and then releases back up when I let go.

DR.SPECKLER · « **Reply #18 on:** Jan 21, 2019, 07:42 PM »

The needle is in backwards.at least most engines the needle pointgoes up in the carb.

meandcuznalfy · « **Reply #19 on:** Jan 21, 2019, 07:42 PM »

meandcuznalfy · « **Reply #20 on:** Jan 21, 2019, 07:44 PM »

Ok, then it should be working, your problem might just be the loose cap on overflow line

DR.SPECKLER · « **Reply #21 on:** Jan 21, 2019, 07:44 PM »

Hard to tell whats going on in pics.you do have the floats?lol

bassin212 · « **Reply #22 on:** Jan 21, 2019, 07:52 PM »

haha yes I do, I didn't take a picture of those because they were clean and moving freely up and down. So you were actually talking about the seat correct? because the floats would be the black things on the side of the carbs?

meandcuznalfy · « **Reply #23 on:** Jan 21, 2019, 07:53 PM »

DR.SPECKLER · « **Reply #24 on:** Jan 21, 2019, 07:57 PM »

Ok make sure the floats dont have any holes by shaking them.there will be gas in them if holes.or float them in gas.put it back together but leave bowl off.hold the carb upright but hold the floats.then see if the float assembly and needle go up and down.dont let it drop to far or the needle will fall out.hard to explain.but gas shouldnt come out the overflow hose.spray carb clean in needle and all jets while you’re in there.

bassin212 · « **Reply #25 on:** Jan 21, 2019, 08:07 PM »

Thanks for the replies everyone. I'm thinking that leaky hose wasn't allowing the bowl to get full and push the floats up and push the seat and needle valve closed. Maybe the long bumpy drive caused the cap at the bottom to shake loose. Either way, before I put the gas line back on the carb, I'm going to put a cut off switch just be sure.

meandcuznalfy · « **Reply #26 on:** Jan 21, 2019, 08:21 PM »

That's a good possibility, happy riding.

Jkoht · « **Reply #27 on:** Jan 22, 2019, 05:13 AM »

If you don't already, I'd reccomend running non-oxy gas in it all the time. It's a little more expensive, but saves trouble down the line. As someone else mentioned the high ethanol content of the regular unleaded really chews up small engines.

jethro · « **Reply #28 on:** Jan 22, 2019, 08:24 AM »

To test to see if the needle valve is sealing closed, take a short section of fuel line, attach it to the carb inlet and use your mouth to blow into the carb. Now turn it upside down. It should now be impossible to blow air into the fuel inlet. Do this a few times, and slowly. The needle valve can stick just a tiny bit and you'll leak fuel.

The shutoff is a good idea to have on sleds with carbs, definitely install one. Make sure it's the correct size, you don't want to starve the carbs of fuel on a 2 stroke because it can lock up the motor.

bassin212 · « **Reply #29 on:** Jan 22, 2019, 09:15 AM »

Do you guys use 3/16 or 1/4 for fuel lines?

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Author Topic: Snowmobile Leaking Gas (Read 2775 times)