Gas Leak

[djg]

I've got an older Stihl 038 chainsaw and it appears to be leaking gas. It leaks more when it's in the upright position so I've been storing it on it's side. It's NOT the gas cap. I've checked that, no wetness. I thought it might be the fuel line grommet between the gas tank and the carburetor compartment. And there is no gas pooling up inside the carb compartment. But when I set it down on a surface, I can see gas accumulating and some dripping when I pick it up to use it. It appears to be coming from the bottom side.

I used it today, but I won't anymore until I get it fixed. Just trying to avoid an expensive shop visit.

 

[pinky]

How long has the gas been in it? Could be varnished up and the needle jet is not seating properly. $5 fix if that is where it's coming from. Watch a you tube video on how do clean and replace.

 

[Graybeard]

I had a stihl weed wacker leak. I replaced the cap and found it was the clear gas tube. It had soften due to time and gas. Something else to check.

 

[djg]

How long has the gas been in it? Could be varnished up and the needle jet is not seating properly. $5 fix if that is where it's coming from. Watch a you tube video on how do clean and replace.

Thanks for the reply, but wouldn't I see gas in the carb/air filter compartment. I'll check again tomorrow. The gas is new, but it did have last year's gas in it.

 

[djg]

I had a stihl weed wacker leak. I replaced the cap and found it was the clear gas tube. It had soften due to time and gas. Something else to check.

The gas cap is not leaking, no gas dripping from the cap. And the tubing is intact or else there would be gas in the carb/air filter compartment. I'll check that too tomorrow. Thanks.

 

[Lou Currier]

@woodtickgreg

 

[Wildthings]

@woodtickgreg

 

[ripjack13]

I'm not sure if anyone knows, but Greg does chainsaw and small engine stuff.
Lemme tag em....

@woodtickgreg

 

[ripjack13]

 

[rocky1]

@woodtickgreg

 

[Nature Man]

@woodtickgreg

 

[woodtickgreg]

Good morning guys, lol.
It could be many things, cap not venting, bad fuel lines, carb leaking, bad vent if it has one, or a bad case gasket. You really have watch it to see where it's coming from. The fact that I'd doesn't leak when it's on its side tells something. Is the tank full when you do this?

 

[djg]

Good morning guys, lol.
It could be many things, cap not venting, bad fuel lines, carb leaking, bad vent if it has one, or a bad case gasket. You really have watch it to see where it's coming from. The fact that I'd doesn't leak when it's on its side tells something. Is the tank full when you do this?

Not sure about gas level; I'll have to check everything out today and get back to you all.

 

[djg]

Update: Finally got around to looking at it again. As I said there was no standing gas in the carburetor area and none on the vent tube assembly. I had been laying it on it's side and no noticeable gas came out. When I lifted it up-righted, I could see gas leaking out of the tank. There appears to be a crack in the gas tank.

The question is now, has this ever happened to anyone and how did you fix the problem?
I would like to just find an epoxy made for cast Aluminum and patch the tank. I would have no problem cleaning off the gas/oil residue and removing paint and roughing up the surface. Any ideas on the epoxy?

As a last resort, I guess I could change the whole tank. I briefly looked on ebay and aftermarket tanks run about $30. But I'm not sure on aftermarket products or how to tackle the project.

Any ideas on how to address this leak would be appreciated.

Thanks

 

[rocky1]

Drain the tank, scuff it good with sand paper, and use JB weld.

There is a product called Seal All you can use to seal the crack itself, it will set with gas in the tank. Then JB Weld over it.

 

[djg]

Thanks, I'll pick some up and give it a try. Haven't had much luck with JB Weld on other projects.

Edit: Why put JB Weld over the top? According to the specs, Seal All is suppose to be pretty tough?

 

[rocky1]

The seal all is tough, but it's kinda like a glue, comes out the tube in semi liquid/gel state. Simply smear it over the leak, and it will seal some pretty good size holes. We were using it on auto gas tanks, catching flying gravel under cars. The Seal All, where exposed, wouldn't stand up to the gravel, hence sealing it, then applying the JB Weld over it. Made for a very durable repair.

 

[woodtickgreg]

If your not going to replace the tank then Rocky's plan is sound. But for 30 bucks I'd just replace the tank and be done. After.arket stuff like that is usually ok, I have used many aftermarket Chinese chainsaw parts and most of them work fine. The Chinese have become masters at copying everyone else's goods and then selling them cheaper.

 

[djg]

Yes I see what you mean. Comes out a little like Shoe Goo only a little thinner. I had the saw turned on the side and starter to sand down the spot I thought the crack was at. Turns out it was at edge or 'seam' (so real joint) of the tank. So I spread it out the best I could using a stick end of a swab. Started to sag so I inverted the saw until it set. I tried to force it around the corner (orange) too. Will put a second coat on in the morning and test it in the afternoon. If it's still leaking, then the crack must run up the tank and I'll have to remove the tank to get to that area.

 

[djg]

If your not going to replace the tank then Rocky's plan is sound. But for 30 bucks I'd just replace the tank and be done. After.arket stuff like that is usually ok, I have used many aftermarket Chinese chainsaw parts and most of them work fine. The Chinese have become masters at copying everyone else's goods and then selling them cheaper.

Agreed, it's turning out that I'll probably have to remove the tank (which I don't know how to do) either way. I just thought I saw a small crack and thought it would be quicker to slap a patch.