Pressure test fail help

[blsnelling]

What model saw are you working on? If your carb leaks against the manifold, it's still an air leak that will cause a lean condition.

 

[Vintage Engine Repairs]

What model saw are you working on? If your carb leaks against the manifold, it's still an air leak that will cause a lean condition.

It’s an ms 260, I have put on order another Intake sleeve - 1113 141 1805
And washer - 1121 121 8600

It may help...?

 

[HarleyT]

You just need a metal block, no rubber piece to test the thing.
Make one out of an old junk carb..

 

[rupedoggy]

Harley you are an Insteen. LOL

 

[Vintage Engine Repairs]

You just need a metal block, no rubber piece to test the thing.
Make one out of an old junk carb..

I did exactly that and it wouldn’t seal. So strange... it must be the connection somewhere and somehow...
When I pulled out the rubber, it looked well formed and sealed. It’s incredibly confusing to me...
It holds if I bung the manifold, otherwise, a block or carb doesn’t seal it. Out of interest, how does one know if their carb seals to the manifold if you don’t test the connection and instead seal over it?

 

[Vintage Engine Repairs]

Could a bent metal oring and seal cause the leak because it won’t sit flush?

I’d have thought the rubber would fill any imperfections. I’m using 5-7 psi.

 

[Mad Professor]

Put a piece of tire tube over it and bolt the carb on

No sense in buying the metal parts, they don't wear, unless a gorilla plays with them.

 

[Vintage Engine Repairs]

put a piece of tire tube over it and bolt the carb on

Hey mate, That’s exactly what I did, and it leaked. It’s the only possible place it could Leake because the bung held pressure?

 

[Vintage Engine Repairs]

Put a piece of tire tube over it and bolt the carb on

No sense in buying the metal parts, they don't wear, unless a gorilla plays with them.

When I pulled off the carb off both the ring and seal were totally bent? I guess I was a little too OTT snugging the carb because it leaked. Couldn’t get them straight again fully so when I try to get the large metal washer thing over the bolts that hold the carb, it wouldn’t go unless I squeezed them together (because the metal outer washer was bent)

 

[Vintage Engine Repairs]

I wonder if the carb I initially used to block it bent it as it was an ms 180 carb so may have squeezed against the washer and oring incorrectly nd then after that whatever I tried nothing would seal it. They should only be a few dollars, other than that I have no bloody clue why it’s leaking. Here is a video for you guys just to show that it MUST be that joint...

 

[Mad Professor]

When I pulled off the carb off both the ring and seal were totally bent? I guess I was a little too OTT snugging the carb because it leaked. Couldn’t get them straight again fully so when I try to get the large metal washer thing over the bolts that hold the carb, it wouldn’t go unless I squeezed them together (because the metal outer washer was bent)

Not sure how those can get "bent".

The ones on my 30 year old 038s are fine

 

[Vintage Engine Repairs]

Not sure how those can get "bent".

The ones on my 30 year old 038s are fine

Honestly, I don’t know either, but it was (still is even after straightening it. You’d Think that you can just take both out and just have that rubber manifold in place and seal it with the carb, but it doesn’t work? I guesss both are there for a reason right... replacing both is the next logical step that I can think of. After than, I’m lost for ideas..

 

[Vintage Engine Repairs]

Pics of the rubber manifold. It’s new. The opening is slightly skewed because the rubber hasn’t seated against the two bolts yet so it’s pushing it in slightly.




Here is how the little I sert got bent, the carb opening (front - i put it in backwards as I didn’t think orientation mattered and now you can see how it squished)

 

[Vintage Engine Repairs]

Of course this may have torn the manifold, but it’s not likely? That could explain that the bung seals that section. Again though, although I’m not ruling it out, I can’t imagine it.

 

[mkinslow]

You do have a clamp tightened pretty snug on the cylinder and intake right?

Sent from my SM-G892A using Tapatalk

 

[Vintage Engine Repairs]

You do have a clamp tightened pretty snug on the cylinder and intake right?

Sent from my SM-G892A using Tapatalk

Yes the 5-6mm recommended spacing on the clamp ends, then I snugged it down all the way and made no difference. Literally the only way it holds air is if I stick that orange thing down the manifold lol

 

[Mad Professor]

For pulling the manifold through the tank housing, use a piece of yarn.

Two/three wraps on the manifold, then pull it through tank housing, pull a tag end on the yarn and it's done.





Works slick as $#!t!

P.S. The highly recommended multi purpose modified tooth brush is pictured. It will let you seat circlips, and get rings started, without gouging your piston.

 

[HarleyT]

Yes the 5-6mm recommended spacing on the clamp ends, then I snugged it down all the way and made no difference. Literally the only way it holds air is if I stick that orange thing down the manifold lol

Your finger is orange?

 

[HarleyT]

Is the hole of your junk carb the same size as the ring?

Looks like that is what bent things.

 

[Mad Professor]

Your finger is orange?

So is our POTUS hair/skin. It don't bother me......