is it possible to patch carburetor diaphragm?

[matt_gs450]

I did a search for "diaphragm" and this isn't addressed. I was walking around with the slide assembly, going to various stores to find a snap-ring pliers that would remove the circlip inside the slide (couldn't find one btw)... and I DROPPED the part about two feet. It was dropped such that the rubber landed first, and the weight of the slide assembly made a small cut in the diaphragm.

The hole is not large at all. 0.5 cm long and less than 1 mm wide. But I can see daylight through it. It can't be good. I was horrified to see that the diaphragm is available for about $125 at a couple online outlets.

Any thoughts on whether this can be patched or will I have to get a new one? Is there an alternative to the OEM part?

Thanks in advance, and I'm sorry for all the new posts.

-Matt

[jimcor]

They can be professionally repaired with your slide and new rubber for less than 125 bucks, but not much less.

I would try one of the Goop brand silicon sealers. They make about 4 or 5 different formulas and despite the name, which isn't very confidence inspiring, they work very well. They are manufactured/distributed by an outfit called Eclectic Products. Check 'em out on-line get the one that will work best with the diaphragm, and offer the best resistance to gasoline.

[jimcor]

Didn't know they made this stuff! Try this.

http://www.eclecticproducts.com/sealall.htm

[REDDY]

NO ! do not try to patch it. Check with any bike shop that works on something besides harleys. Also there are lots of GS ers that have some in a box in their shop. Do a parts wanted thingie and somebody will have one.

[jimcor]

NO ! do not try to patch it. Check with any bike shop that works on something besides harleys. Also there are lots of GS ers that have some in a box in their shop. Do a parts wanted thingie and somebody will have one.

Why not? What's the problem?

[matt_gs450]

Given the alternative, I'm certainly inclined to try and patch it. I'll wait a couple days to see if there are other products people would suggest. Otherwise the Seal All looks promising.

Here is the damage. The actual puncture is smaller than the indent that you see:

[anikmankar]

NEver tried it but check if the Tube tire puncture patch works...

[bwringer]

Silicone will quickly deteriorate in the presence of gasoline vapor, so that's no good.

Does Seal-All remain flexible once cured?

Your best bet is a used diaphragm.

[Can_O_Tuna]

You might want to try a bike junkyard if there is one near you. If you seal it, it may work, but for how long? Then you would have to tear everything down again.

[KennyJ]

A common problem with FJ Yamahas. Since the parts are quite expensive and not regularily stocked most have gone to fixing them with plasti-dip (the stuff you dip your tools in to coat the handles, available at NAPAs). Seems to work well for all that tried it.

http://www.plastidip.com/consumer/index.html

Go to the FJ Yamaha group on Yahoo and do a search. I believe they thin it with mineral spirits a bit before they brush it on.

And why not try...worst you can do it make it run the same. I would put it in an outside carb so I could reach it for replacement if the repair doesn't work.

Kenny

[Jethro]

I have tried to repair one in the past by heating up a piece of heavy wire cherry red and ever so slightly trying to "weld" the rubber back. It sealed no problem- BUT, the slide didn't return that well. If there is any inconsistancy in the rubber, the action of the slide gets a little messed up. This is a CV carb, right? They are the only ones with diaphragms if I remember correctly. The action of the slide needs to be smooth and perfect for it to work well. I'd look for a replacement.

One of the best things I ever did was buy a used carb rack on Ebay. I suggest you look on there or at a wrecker.

[matt_gs450]

I bought a tube of Seal All. I'm going to try a thin film of that as a patch first. If that fails, then I did just buy another 450 which I could cannibalize for the diaphragm. I'd really rather not do that because I'd like to get the new one running (according to PO, it's a charging system problem).

First though, how can I get that circlip out of the slide??? It's down in there about 2" and I can't find circlip pliers in any store that will fit inside the cavity. I assume the part is available through Snap-On, but I'm not going to order a $25 tool sight-unseen if I don't know it's the right one.

Does anybody know what tool I can order which will do this job?

Thanks,
Matt

[hwb120240]

Absolutly you can repair the diaphram! Another forum I frequent has a step by step:

http://forums.delphiforums.com/TAZZZ2U/messages

Look under "Repairs Everyone Should Know". Lots of us (V4 Riders)have done this.

[jimcor]

From the Madura site:

2583.1 In January of last year while checking the sync on my carbs, I noticed #1 & 3 cylinders, fluctuating badly on the mercury gauge, while 2 & 4 were steady as a rock at 18cm mercury. So, I started checking for vacuum leaks, and ended up finding them caused by very small tears in the slide diaphragms on the carbs.
After pricing replacements through Suzuki ($120.00 per slide assembly) I decided to create a repair that would work.
I've waited just over a year to post this, so I could be sure of the reliability factor.
The tears in the diaphragms were caused simply from the movement over time, causing a slight crease and weak spot in the rubber, which finally lead to a small hole. Both of my slides had holes not much larger than pin heads, but under vacuum, they caused leaking, hence the fluctuation, and lack of throttle response.
I made the repairs by buying a box of latex surgical gloves, a tube of clear silicone adhesive, an artists paint brush (with bristles 1/4" wide).
Remove the affected slide, and thoroughly clean the diaphragm with mild dish soap, warm water, a cotton ball or Q-tip, to remove any dirt, residue, etc, for good adhesion when applying the fix. Air dry with low air pressure or hair dryer.
Using one of the latex surgical gloves, (Note: these will have been coated with powder to make them easier to put on your hands. So you will need to wash them as you did the diaphragm to remove the powder) cut a small round patch out of the glove. I made mine 1/2" diameter.
Using the clear silicone and the artists brush, paint a thin even coat of silicone over and around the tear. place the patch you've mad over the tear, centering the patch over it. Wait approximately 30 minutes, then again using the brush, place a thin even layer of silicone over the patch, overlapping the edge of the patch a 1/16" or so. Allow the patched slides to dry overnight for complete adhesion, then reassemble and check carb adjustment.
As I said, I made this repair a little more than a year ago, and yesterday, I pulled the slide covers and using a strong magnifying glass (old eyes ya know) I found NO further deterioration of the diaphragms or the patches I made. And on the mercury gauge, the carbs are rock solid, with NO fluctuation. I've also since done this same repair to 2 Harleys, a Suzuki Cavalcade, and a Kaw Vulcan, all with the same reliable results.
Hope this saves some folks some money.

[jimcor]

Does anybody know what tool I can order which will do this job?

Thanks,
Matt

Oh, what the hell is the correct name for that surgical tool that clamps veins and stuff? You know the roach clip thing. :shock: Can you reach down there with one of those? You can get the Chinese made ones at Harbor Freight cheap.

Hemostat ahhh, thank you answers.com Will a pair of long nose jobs work? My friend keeps long nose hemostats for fish hook removal in his tackle box.