372 intake boot how are you guys torquing them?

[Brent Nowell]

Recently my 372 intake boot had an air leak, this is where the carb meets up with the boot. I have already ordered replacement parts which include the boot and the ring that the bolts thread into.

While I am waiting I have tried to get my old intake boot to seal, I have tried EVERYTHING I can think of....

There are no visible tears that I can see I have inspected it about half a dozen times now. The flange of the boot looks fine and every time I put it back on I spray a shot of carb cleaner down to this area and the saw stalls....
I have tried greasing the boot to carb mating surface
I have tried using just minimal tightness on the bolts, I have tried snugging them up even more
I have tried RTV twice now, both times have failed to get rid of this air leak!!! I am fricken stunned to say the least....

My fear is that the new boot and ring come in and I install them and I have the same results.
I have confirmed that there is no other area of the boot that is leaking, including the cylinder mating area. Again I have sprayed these areas with carb cleaner while it is running and no effect. But if I spray the carb to boot mating area where the throttle cable is, stall...

Help me out here

 

[Ketchup]

1184?

 

[Ronie]

Wish I had a solution for you. Could the throttle shaft be leaking?

 

[U&A]

I guess my question is how do you know your air leak is coming from the intake boot?


Sent while firmly grasping my redline lubed RAM [emoji231]

 

[Ronie]

I guess my question is how do you know your air leak is coming from the intake boot?


Sent while firmly grasping my redline lubed RAM [emoji231]

I have sprayed carb cleaner around the intake boot and had the idle change because some of the cleaner was sucked into the air filter.

 

[Andyshine77]

Carb cleaner will always do that pretty much no matter what, solvents like that wick through almost any seal. Plus the vapors will get in the intake. You should use WD40 so if you do have a large air leak it will provide some lubrcatio. Also the plastic flange can only be used so many times before it deformes, especially if you over tighten it.

 

[Ronie]

I had a carb leaking at the flange once and if I'm remembering correctly the metal insert in the flange had been tightened to tight and had pulled out a little keeping the carb from seating. Just throwing ideas out there.

 

[Brent Nowell]

Carb cleaner will always do that pretty much no matter what, solvents like that wick through almost any seal. Plus the vapors will get in the intake. You should use WD40 so if you do have a large air leak it will provide some lubrcatio. Also the plastic flange can only be used so many times before it deformes, especially if you over tighten it.

Alright, well I guess I’m just gonna have to accept that it’s deformed enough cause I have overtightened it. This problem is driving me nuts lol I’ve taken that carb off and boot about 7 times now re trying things.

The leak is def bad enough that the saw is climbing in rpm then lowering over and over.

Gonna wait for new parts, probably pull the jug and put it on as straight and delicate as possible. If I have to I’ll get longer bolts and trim them to size and get the thinnest cork gasket material I can find and hope that works with the new parts!!!
Manual says 2NM for torq whatever the hell that is. But I do have a torque screwdriver from my scope mounting kit that should be able to torque it accurately.


Interesting comment about the throttle shaft, which is plausible. I do remember having my 455 throttle shaft leak air and there wasn’t nothing I could do about it... I always thought they all leaked a little air...

 

[Brent Nowell]

I had a carb leaking at the flange once and if I'm remembering correctly the metal insert in the flange had been tightened to tight and had pulled out a little keeping the carb from seating. Just throwing ideas out there.

Ronnie throwing ideas out there is awesome that’s what I’m looking for cause I’m Out of ideas myself
Yours was probably the non x torq edition cause there is def no metal insert for this saw, just the boot and the plastic collar. But I’m gonna go with the fact that the collar is done... can’t wait to get these parts and if they work I’m gonna literally burn the old ones so I never go through this much work again haha

 

[Ronie]

There should be some metal inserts in the flange.

 

[Andyshine77]

Replace the boot and mounting flange. NM= newton meters, just cross referance it it inch pounds. Use a paper gasket or syn fiber type not cork.

 

[Andyshine77]

There should be some metal inserts in the flange.

View attachment 761224

I believe the 372 is just plastic no inserts.

 

[Ronie]

I believe the 372 is just plastic no inserts.

That's a 372 xtorq flange.

 

[Ronie]

Maybe the had them with and without the inserts.

 

[Andyshine77]

Maybe the had them with and without the inserts.

I don't remember metal inserts on my OE 372 xt may be different, that or my memory is shot lol.

 

[Andyshine77]

Also you don't want to use rtv to get the carb to seal, not a good solution.

 

[Ronie]

I just pulled the flange off a 2172 carcass and it has metal inserts.

 

[Ronie]

I would give the new flange a try before pulling the cylinder to change the boot out.

 

[Andyshine77]

Ok I was incorrect, I guess I'm just used to these darn 50cc husky saws, those 100% are all plastic.[emoji111]

 

[Ronie]

Ok I was incorrect, I guess I'm just used to these darn 50cc husky saws, those 100% are all plastic.[emoji111]

Maybe it was both ways. I haven't had but a couple of of them so I'm no expert.