372x torq boot heads up

[Brent Nowell]

I’m bored so I thought I’d take the time to post something someone might find useful

Did some milling today with my newly assembled 372 xtorq with a pop up piston and no base gasket.

Was running a little funny, and like an idiot I ignored it. Did a couple passes, then shut her off, and re fueled. Fired it up and idle was up and down, so much that I realized that I can’t ignore it.
Fired it up and started spraying carb cleaner to find the leak and checked the jug continuously and no dice. Then sprayed the boot and she stalled, right underneath to be exact. Confirmed it a few times and realized the boot has a massive air leak so I tore it apart on the bench.

Pulled the jug with the intake just to make sure nothing was fried or starting to, and it all checked out quite nicely.
Looked at the boot and couldn’t find anything wrong, rubber is still very in tact, so I started to see how well it mounts to the carb.

The little rubber separator that extends into the carb, had gotten caught and folded over when I re assembled. It was real easy to do, .

If your putting an 372 xtorq carb back on, make sure that the rubber divider is in the slots of the carb, cause if it isn’t it will fold and no matter how tight you do it, it will leak.

Anywho thx for listening

 

[brad ruch]

Well I'll be danged.i just recently did my jred 2166 no base gasket.and hadn't run it till labor day for the first time.and it was doing the exact same thing your talking about.first thing I thought was a air leak.so last weekend I pulled the carb and muffler and did a pressure vac test.i have the OEM block off plates.low and behold no leaks at all.so put it back together.havent run it yet.but now I wonder if the first time I had that flap kink like ya said.[emoji23][emoji23][emoji23]

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[Brent Nowell]

Haha crazy! I tightened it so much it cut the divider on the corner ever so slightly.
Gonna play with it as soon as I get home and mill some more wood see how she runs

 

[Brent Nowell]

Bah still leaking!!! Same area, absolutely not on mug side of plenum wall it’s for sure at bottom of boot where carb connects. Tested the pulse line with pressure and vacuum and it’s good....

It’s like the plastic collar that mounts the boot to the carb is not making a deal cause I cannot find a tear...

The divider has a chunk out of it now which I’m sure will create tuning problems... sigh it’s either a new boot or take out the divider throughout....
one thing is for sure I do not want to take that jug off for a third time

 

[brad ruch]

Aahh crap I have gutted the intake on one before.filter holder and boot.not the carb though.

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[Brent Nowell]

Still gotta figure out why it’s leakin, thinking of putting an o-ring behind the lip of the boot to assist the plastic collar in making a seal...
probably gonna try that first and identify the leak before I start carving crap up

 

[brad ruch]

Gosh now I wanna see how mine is.[emoji849][emoji849]

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[Brent Nowell]

Well I have combed over this thing for a good bit and I can’t see what the problem is... am I overtorqing the bolts causing a kink?
The surface was oily when I assembled it so it wasn’t dry and pinched...

Anybody with any insight please let me know. Gonna probably just order a new one and I’m thinking of ordering a plastic backing piece as well...
I found the slightest tear but it doesn’t go all the way through...
Thoughts??

 

[brad ruch]

I would try a new boot.and yes you can over tighten those bolts to much and cause a leak.they should be only snug like 3-4 threads sticking out the opposite side.

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[Brent Nowell]

I would try a new boot.and yes you can over tighten those bolts to much and cause a leak.they should be only snug like 3-4 threads sticking out the opposite side.

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Did some research



Looks like a common problem, I think your right and I overtightened the bolts...

Gonna try making a gasket I think or using some rtv. Hopefully it will work until I get a new boot

 

[Edweiser]

You may of warped the plastic piece when you over tightened it with the flap in the seal. That small chunk missing shouldn't effect anything as far as running or the seal. I don't like the partial rip, will cause problems later. Best to change both. Personally I apply grease in between the boot and carb and as you know watch it close and bring the screws in evenly. Trying to add an o ring will complicate things worse

 

[Brent Nowell]

Edwieser thanks for the info.
I’m gonna stop into wholesaler to get a new boot and new ring.
Gonna see if I can bend it the opposite way or something, I have a week till parts get in so can’t help but tinker and try new ideas