husky 357 zama carb

[chuckp]

I just installed a new zama carb on my husky 357. I can't get it to seal. I'm afraid to over tighten the carb screws. They self thread into a plastic flange. I just ordered the ring on the bellows. I assume that's where I have the leak. No gasket, but a little cheap plastic ring. Any tricks to try while I'm waiting for the part? Can I apply some sealant on the ring?
I'm not impressed by the cheapness of this saw. Plastic which can be removed and re-installed only a few times. I have two old husky 61's that are built much better than this 357.

 

[JP56]

You could always make your own gasket and try it without the rubber ring.

 

[HarleyT]

The ring is just in the center, correct??
The flat surface that the carb sits against is rubber?
The center ring is usually just an expander, that prevents the rubber from pooching together.
What makes you think that it is not sealing?

 

[chuckp]

I spray carb throttle cleaner at the connection and the engine dies.

 

[chuckp]

the ring is in the center, it's plastic, not rubber.

 

[HarleyT]

The mating surface. The flat spot, is it rubber?

 

[HarleyT]

Is this it?

 

[HarleyT]

Here, is it this setup?

 

[HarleyT]

The carb presses against the flat of this rubber piece, and the ring goes in the center of the boot. Yes?

 

[cuinrearview]

It does not seal to the ring.

Spraying that close to the carb is not an indication.

 

[chuckp]

Why isn't spraying that close to the carb an indication?
The plastic ring looks like it protrudes past the rubber and stops the carb from seating. I'm afraid to crank down on the carb screws. They self tap into the rubber base. I've already installed and removed the carb multiple times. I think this is a terrible design. Made to fail!
By the way, thank you very much for responding. I don't pretend to know what I'm doing.

 

[chuckp]

Here, is it this setup?
View attachment 889541

That's it. Looks to me that the plastic ring (503928801 makes contact with the carb before the rubber flange does. If I could crank down on the two mounting bolts, I could probably push in the plastic ring and make better contact to the rubber flange base.

 

[user 122190]

I used an epoxy in the threads. Fill them up, let em dry, drill it out, then install. The epoxy holds up to the tight threads better then just the rubber. The 357 is a PITA.

 

[cuinrearview]

You should be able to push the ring in first. The rubber intake has a raised ring to create the seal.

 

[cuinrearview]

What prompted you to do this test? Is it not running right?

 

[cuinrearview]

Does your saw still have this plastic clamp setup to attach to the cylinder or have you updated it to the metal clamp?

 

[Huskitoter]

The plastic ring looks like it protrudes past the rubber and stops the carb from seating.

Would the carb get impulse to run if it wasn't seating? I'm guessing you sprayed toward the cylinder (away from intake). Could it still be sucked in the filter or maybe a leak toward the cylinder? Got a metal clamp on the boot?

--- CU posted while I was typing

 

[cuinrearview]

Why isn't spraying that close to the carb an indication?

This

Could it still be sucked in the filter or maybe a leak toward the cylinder?

 

[chuckp]

what prompted me to do this test is I got rid of the plastic clamp, replaced it with the metal setup. Replaced the carb with the zama too. Just testing my new parts.
For the heck of it I made a gasket, installed it. To tell the truth the saw seems to be running well. Then I sprayed the carb spray and the saw crapped out.
I like the idea of the epoxy in the screw channels.
I sprayed the carb cleaner above where the plastic ring butts up to the carb. I'm tempted to tighten the carbs screws some more and re-test.

 

[HarleyT]

Just put a smear of grease on the surfaces, and see if it still does it. The grease would seal it enough to tell if it was leaking there.