Possible Diaphram Problem

Ok, so, I have just finished rebuilding my cv carbs. The service manual states that to test for proper diaphram installation, you can push the needle piston all the way up, seal off the air intake hole with your finger and the piston should take 10+ seconds to descend back into rest position. (~3.5mm above needle-jet) My first carb passes this test (11+ seconds). The second one only takes 3 seconds to slide down. I have reinstalled it multiple times just to double-check myself. Diligent visual inspection of the suspect diaphram shows NO DAMAGE.

So my question is, is this a fail-safe test? If one vacuum piston is falling faster than the other, is this going to completely screw up the slow-down after the gas is eased off? After all of the hard work put into cleaning them really well, I'm pretty frustrated at the possibility of damage.

I think I will try to swap the diaphrams from carb to carb and see if the symptom follows. Probably will. UG!

Any suggestions would be appreciated. Thanks guys.

when you have them out hold it up to a light and look for pinholes :ohmy:

This is proberbly the scariest title for a thread I've ever came across. Possible Diaphram Problem. Man it sends shivers right up my......

Seriously I think you're doing it right see if the prob follows the diaphram. Luck

ambergrismooon wrote:

This is proberbly the scariest title for a thread I've ever came across. Possible Diaphram Problem. Man it sends shivers right up my......

Seriously I think you're doing it right see if the prob follows the diaphram. Luck

Amber, you owe me a keyboard...:blink:

How'm I supposed to get all this coffee 'n snot out from 'tween all these itty-bitty keys?

ambergrismooon wrote:

This is proberbly the scariest title for a thread I've ever came across. Possible Diaphram Problem. Man it sends shivers right up my......

:laugh: Haha! I thought the same thing when I read that title! I had a diaphram problem about 20 years ago. Now it's costing me a boatload to put her through college!:S

Pterosaur wrote:

ambergrismooon wrote:

This is proberbly the scariest title for a thread I've ever came across. Possible Diaphram Problem. Man it sends shivers right up my......

Seriously I think you're doing it right see if the prob follows the diaphram. Luck

Amber, you owe me a keyboard...:blink:

How'm I supposed to get all this coffee 'n snot out from 'tween all these itty-bitty keys?

After several milliseconds to think it over (and getting the tale of the tape over in the *packin' heat thread*), Gris, you owe me absolutely, utterly and positively NOTHING. Zip. Zero. Zilch. NAAADAAA.

Matter of fact, can I get you some coffee? A soda? Some beer, maybe? Wad myself in a ball and toss myself into the corner? Hmmmm? :blink:

Yarg, it followed the diaphram.

Which, whether you were serious or not, led me to checked for pinholes.

This is what I found:



Is there some light apoxy i could mend the rubber with? (haha, i said rubber too. :pinch: )

I don't know how that got up there twice. Many thanks to my girlfriend for putting up with a kitchen table covered in carburettor parts.

mind2find wrote:

I don't know how that got up there twice. Many thanks to my girlfriend for putting up with a kitchen table covered in carburettor parts.

Eeeeek!

Mind! Don't look now, but some homeless dude straight outta' *12 Monkeys* wandered through your back door and is munching on your floats! :woohoo:

(sorry...couldn't resist)

Post edited by: Pterosaur, at: 2006/05/16 22:10

quite alright 'saur. although i'm not sure your average homeless person would be wearing goggles and a breathing mask to protect them from cancer-causing carb cleaner (CCCC).

but seriously, if anyone knows how i could patch this, i'm dyin' to hear this thing rev up. :woohoo:

mind2find wrote:

I don't know how that got up there twice. Many thanks to my girlfriend for putting up with a kitchen table covered in carburettor parts.

Don't worry about the double posts, it just happens sometimes and one of the mods will delete it sooner or later.

My wife don't even blink an eye at a motor apart on the kitchen table anymore, she gave up on ever civilizing me

Forgot to answer your question :blush:

Try a real thin coat of liquid rubber over the area where the hole is.

Post edited by: steell, at: 2006/05/17 00:30

i used a rubber spray on mine i used plastidip spray and was told after i should have gotten the nitrile rubber spray from napa. no napa in wichita anymore . so far ive gotten 4 weeks and they run great