372xt won't stay running, dies in the cut, hard to start.

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edrrt

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I was gonna grab one of the clones but saw this on craigslist for $275 with a 32" bar/ chain so I decided to take a swing at it.
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The guy said that he used it for firewood and it ran fine when he put it away. Looks to be all OEM. Started it up in his driveway, was a little hard to start but got going okay, throttle response was good, it seemed to idle fine so I bought it. Today I try to start it up and it's very difficult to get going.

I found that the choke lever was disconnected.

With it connected it's very hard to start. It seems like it floods out. Cylinder is soaked and there is gas in the air intake.

Compression seems to be about 155.20230410_180337.jpg

Trying to start it It often races as soon as it turns over and then dies immediately with choke on. Without the choke it's very hard to start get it to turn over.

With a lot of attempts I can get it running and when it's running it seems like it runs well. It idles fine, it has good throttle response, everything seems normal. I sprayed some carburetor cleaner around the boot/ decomp looking for air leaks and found none.

Then I tried to make a test cut and once it gets up to RPM in wood it immediately bogs down and dies.

I'm assuming this is a carburetor problem. The lowjet only turns between 9 and 3 o'clock. I have it set halfway between. I did not mess with the high jet because it seems to be okay on the high end. And I adjusted the idle.

I'm not sure what to trouble shoot next?
 
I was gonna grab one of the clones but saw this on craigslist for $275 with a 32" bar/ chain so I decided to take a swing at it.
View attachment 1074288

The guy said that he used it for firewood and it ran fine when he put it away. Looks to be all OEM. Started it up in his driveway, was a little hard to start but got going okay, throttle response was good, it seemed to idle fine so I bought it. Today I try to start it up and it's very difficult to get going.

I found that the choke lever was disconnected.

With it connected it's very hard to start. It seems like it floods out. Cylinder is soaked and there is gas in the air intake.

Compression seems to be about 155.View attachment 1074289

Trying to start it It often races as soon as it turns over and then dies immediately with choke on. Without the choke it's very hard to start get it to turn over.

With a lot of attempts I can get it running and when it's running it seems like it runs well. It idles fine, it has good throttle response, everything seems normal. I sprayed some carburetor cleaner around the boot/ decomp looking for air leaks and found none.

Then I tried to make a test cut and once it gets up to RPM in wood it immediately bogs down and dies.

I'm assuming this is a carburetor problem. The lowjet only turns between 9 and 3 o'clock. I have it set halfway between. I did not mess with the high jet because it seems to be okay on the high end. And I adjusted the idle.

I'm not sure what to trouble shoot next?
Running lean, needs to have a vac -pressure test before it lean seizes.
 
your tank breather maybe plugged , hole in the gasline,, carb rebuild time or a coil could be at falt- usuall the order i go at them.
I hear is squealing sound while the saw is sitting like air leaking past a restriction. Like When the saw is sitting in the sun it can't equalize the pressure from somewhere.

Does that sound like the tank breather?

Where is the tank breather?
 
What is your starting procedure? The high speed adjustment is the most important one, if the saw bogs in the cut, it is NOT ok. Do a search on how to tune a saw
I tried to look up how to tune that particular saw. The manual just says turn the low jet all the way anticlockwise and then try and start and run the song. If it bogs down turn it clockwise.

My starting procedure is to pull the choke out which locks the throttle back. Press the decomp. Pull until turns over. Then put choke off and, press the decomp and start, then after it starts to depress the trigger to slow it down.

Then while it's running an idling turn the low jet until when you squeeze the trigger it doesn't bog. And turn the idle up until it stays running without moving the chain.


I did not mess with the high jet because it has a limiter on the top end and it sounded okay on the top end it wasn't really four stroking. Bias should I try turning the hijet a preset amount?

It seemed like it started in ran okay until I reconnected the carburetor choke screw to the lever. I question whether or not you can install that in some position that was wrong but it doesn't seem like it.
 
Running lean, needs to have a vac -pressure test before it lean seizes.
I agree, one of the tools I use all the time, will tell you wheather your seals, boot etc have an air leak and you will have a chance to look at what shape your piston is in.
 
I tried to look up how to tune that particular saw. The manual just says turn the low jet all the way anticlockwise and then try and start and run the song. If it bogs down turn it clockwise.

My starting procedure is to pull the choke out which locks the throttle back. Press the decomp. Pull until turns over. Then put choke off and, press the decomp and start, then after it starts to depress the trigger to slow it down.

Then while it's running an idling turn the low jet until when you squeeze the trigger it doesn't bog. And turn the idle up until it stays running without moving the chain.


I did not mess with the high jet because it has a limiter on the top end and it sounded okay on the top end it wasn't really four stroking. Bias should I try turning the hijet a preset amount?

It seemed like it started in ran okay until I reconnected the carburetor choke screw to the lever. I question whether or not you can install that in some position that was wrong but it doesn't seem like it.
Turning the low screw anti clockwise would be way fat, or too rich. Me thinks you read the tuning procedure wrong. You tube has many videos on proper tuning procedures.
 
Turning the low screw anti clockwise would be way fat, or too rich. Me thinks you read the tuning procedure wrong. You tube has many videos on proper tuning procedures.
Screenshot_20230411_175423_Chrome.jpgYou are right. It should be the other direction.

Then it only gives you 180° rotation before hitting the stops. I will start with that. But I had it set halfway between and it didn't seem to make much difference.

I haven't messed with the high jet. The manual gives no indication as to where you should start to have it set.

Screenshot_20230411_175453_Chrome.jpg
 
On paper you got a good deal. I would have also jumped on it.

I agree with others. Needs a vac/pressure test to make sure there are no leaks.
Then, new fuel lines and tank filter.
Then a carb rebuild.

How does the piston and cyl look thru the exhaust port?

See where you are at from there.
 
On paper you got a good deal. I would have also jumped on it.

I agree with others. Needs a vac/pressure test to make sure there are no leaks.
Then, new fuel lines and tank filter.
Then a carb rebuild.

How does the piston and cyl look thru the exhaust port?

See where you are at from there.
I think the Piston looks good although taking the muffler off the sure is a lot of oil everywhere. Looks like it's so wet and flooded. They're also does not appear to be a muffler gasket which probably I'm guessing there should be?

The rings look good, the top of the piston looks good, there are some ever so slight lines on the bottom. And the cylinder looks good from above.


20230411_203459.jpg

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How does one vac test a 372 XT?

I know you block the exhaust port off. But then how do you block off the carburetor side?

I tried doing a vacuum test on the gas line and I don't get any leak. Someone on YouTube said that you can get a needle valve leaking in the carburetor That will cause it to bleed down.20230411_210026.jpg

Something that I can't explain is with the saw upright as you see it and the fuel line disconnected from the carburetor. The second I closed the gas cap fuel runs up the hose and starts pouring out like there's pressure in the gas tank. As soon as I close the gas cap gasoline starts pouring out of the carburetor side of the fuel line almost like it's under intense pressure.

Is that normal?

Or does that indicate the breather is not working well.

I can blow through the breather but it is very tight. That would explain the hissing that I hear from the saw. And why it would lean out in the cut and die maybe?

And also why when trying to start the saw the thing always seems completely flooded.

My guess is if the tank isn't breathing when it's sitting it makes pressure that pushes a bunch of gas into the carburetor and then when you run it it creates a vacuum and leans out the saw.

Unless it's normal to barely be able to push any air through that breather blowing is hard as you can?
 
The carb pop off is high, someone here will give an exact value but 30-50psi? The service manual may list it.

So you can check the carb pop off pressure to confirm but the tank pressure should never get high enough (more than 8 psi or so) to flood the saw through the carb when sitting if the needle and spring are good.

Yes it is normal for the tank to be pressurized. The vent is one way (into the tank). Again service manual will have specs to test the vent.

372 is a very popular saw so you should quickly find vac test details with a Google search.
 
The carb pop off is high, someone here will give an exact value but 30-50psi? The service manual may list it.

So you can check the carb pop off pressure to confirm but the tank pressure should never get high enough (more than 8 psi or so) to flood the saw through the carb when sitting if the needle and spring are good.

Yes it is normal for the tank to be pressurized. The vent is one way (into the tank). Again service manual will have specs to test the vent.

372 is a very popular saw so you should quickly find vac test details with a Google search.
Sounts like with the X-torq you gotta buy a sacrificial carb, fill the thing w silicone, and bolt that on them connect to the impulse line.

Not easy. Makes me wonder if I should just take it to a saw shop and have them go through it.

There's not much adjustment on the carburetor. Both the high and low only go 180°.

I feel like it's probably a carburetor issue but I'm unsure how to set it up initially.
 
The piston and cylinder looks good in the photos. I would want to know there is no air leak.

But you could roll the dice and move on to the next items I listed.
All new lines and a carb rebuild.
 
The piston and cylinder looks good in the photos. I would want to know there is no air leak.

But you could roll the dice and move on to the next items I listed.
All new lines and a carb rebuild.
I sprayed around with carb cleaner, boot, decomp, base, impulse... Didn't get any faltering at all.

Is the gas tank vent supposed to be that tight?

And anyone know the initial carb settings for a XT?

Is it possible it's just carb settings or with the limiters is it more or less impossible The settings could be so far off that it wouldn't start or run now?

I guess I could try swapping the fuel mix too. I was using a rich milling mix. Maybe the epa saws don't like it?
 
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