huskie 3120xp with an air leak somewhere help?

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cponick

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Okay i need some advice on where to go next. I recently just bought a 3120xp almost brand new, was in the box but never ran in the wood supposedly. So the important thing is that i can't take it back for warranty. So i got it and fill with fresh gas 40:1 and oil and it was really hard to start when following the manufactures directions. I played with it a little more and finally just figured that something it wrong. So i replaced the fuel line from the tank to the carb and that helped a lot. She started cold with out any real problems. about 5 pulls with the choke and then 2 to 3 without choke and she would be running. But a hot start was still really hard. And then when she did start it was obvious that there was air getting in somewhere as it would start and run for a second and then bog down like its running out of fuel and then run for a second and bog and then run as it finally got all the air out. So i pressure tested the carb and sure enough it was leaking. i put a new carb kit in and it hold 12psi all day long. yesterday when i was out milling it started again. really hard to hot start and when it did finally start it had air in the line somewhere as it would run then bog then run then bog for a few seconds till it purged the air. So what is the next step. I can't imagine that the carb kit is bad already, and if it is what would cause that with only about an hour of run time. its got brand new software from the tank to the carb, what am i not thinking about. help please.
 

cponick

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Still no solid outcome. The vent is venting the way it should, I pulled the carb apart again and cleaned it out again. There was a little bit of dust inside when i opened it up. So I ordered a new air filter and gasket to try to keep the dust out. But i milled up a few giant cookies about 4ft around last weekend and it ran okay. Some times it was perfect and others there was an air bubble in the line when started. So still not sure.
 

rogue60

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Sounds like the fuel is boiling coursing vaper lock common with a heat soaked saw and the rubbish pump fuel not designed for o P e we have now days.
40:1 milling with a 3120 and no H adjustment yeah I'd be pulling the muffler for a look at the piston also.
 

cponick

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Outcome is still unknown. I pulled the carb apart again and cleaned it very well. There was a little bit of sawdust inside so I have ordered another air filter. Not exactly sure how it's getting in. But we'll see. I know I won't buy another brand new saw again. I expect a few problems from an old saw that I build. But not from something still in the box.
 

cponick

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Well muffler was pulled off and piston looks perfect. I did put a slightly more opened up dual port muffler on it and it significantly helped with getting rid of the heat. I don't think it's a boiling fuel problem cause it's mostly a problem in getting restarted after she has been sitting for 20 to 45 mins. Like after I file the chain. Then really hard to get started and it's like there is an air bubble trapped inside the fuel line or the carb. And once I get through that first couple seconds of running it runs like a champ.
 

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Okay i need some advice on where to go next. I recently just bought a 3120xp almost brand new, was in the box but never ran in the wood supposedly. So the important thing is that i can't take it back for warranty. So i got it and fill with fresh gas 40:1 and oil and it was really hard to start when following the manufactures directions. I played with it a little more and finally just figured that something it wrong. So i replaced the fuel line from the tank to the carb and that helped a lot. She started cold with out any real problems. about 5 pulls with the choke and then 2 to 3 without choke and she would be running. But a hot start was still really hard. And then when she did start it was obvious that there was air getting in somewhere as it would start and run for a second and then bog down like its running out of fuel and then run for a second and bog and then run as it finally got all the air out. So i pressure tested the carb and sure enough it was leaking. i put a new carb kit in and it hold 12psi all day long. yesterday when i was out milling it started again. really hard to hot start and when it did finally start it had air in the line somewhere as it would run then bog then run then bog for a few seconds till it purged the air. So what is the next step. I can't imagine that the carb kit is bad already, and if it is what would cause that with only about an hour of run time. its got brand new software from the tank to the carb, what am i not thinking about. help please.
If you can get an aftermarket carb. for it I would try that because it don't cause much money or investment.
It will give you a pointer if it is the carb. that is the cause of the problem.
If it have little use its not likely the crankshaft seals that is almost always my main suspect...
On my latest repair job a 025 I replaced all rubber parts and it was still leaking, turned out a little gasket silicone at the carb. gasket solved it.
Not running properly, making no sense to tune the carb. - especially at idle. - its a leak.
 

rogue60

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In my experience vaper lock is more so a problem after shutting off a hot heat soaked saw restarting can be a pita.. I've had to let things cool off for 30min easy before it'll restart before.
Also if a saw is pushed to extreme boiling fuel can also start to lean out a running saw I've experienced both above scenarios.
 

cponick

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So if it is a vapor locking issue from being overheated? wouldn't i be seeing some scaring on the piston? The piston still looks brand new. But what are some better ways to get more of the heat out of this. I took it milling this weekend and she ran better. Still a little bit of an issue getting restarted after she sat for about 25 to 30 minutes, but not as bad. But it was getting a bit warm. I'm always open to a better way to do things as this is going to be my primary milling saw, whats the best way to get more airflow and cool it off better. The aftermarket dual port muffler helped a lot, anything else I can do?
 

rogue60

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Who knows what the exact problem is with ya saw it's a "new" saw you shouldn't need to be replacing carb kits fuel lines the 3120 is a relative reliable saw.
Vaper lock is just one of the possibilities as to why it's playing up.
If it is Vaper locking it has nothing to do with the saw overheating it's to do with the fuel having a low boiling point.
Modern pump fuel is rubbish it's designed for modern engines in vehicles that have very high fuel pressure (high fuel pressure raise the boiling point) and it's constantly circulating back to the tank and fuel lines etcetera are better shielded from heat. Because of this they have taken out the anti boiling additives that used to be in pump fuel. it's not even designed to be run in op e unfortunately they care less it's all about the bottom line.
One way to trouble shoot a saw that could be vaper locking to is to try a different quality fuel like some of the canned fuels made for op e.
Also after a long milling cut and the saw is fully heat soaked let it sit a couple minutes after shutting it off then open the fuel cap and look if the fuel is boiling if it is you have found ya problem.
 

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