Carb-plugs SFC1000

Dellortoman said:
You don't necessarily have to replace the choke plungers if they're not sealing properly. Have a look at the little rubber seal on the tip. If it has a groove worn into it from the fuel aperture seat, hook the little ribber disk out with a pointed tool, flip it over and push it back in so the unused face is now doing the sealing. If you've already done that and both sides of the rubber seal are worn out, or it has gone hard, you can replace the rubber tip without having to buy a whole new brass plunger. Grab a small piece of 2mm thick viton sheet and a hole punch (6mm I think, but could be 5mm - memory is a bit hazy) and you can punch out as many little sealing disks as you need. Just flip the old ones out of the choke plungers and pop the new ones in. I dunno why Dellorto carb rebuild kits don't come with a new choke rubber. They have a bunch of other rubber O-rings and stuff in them.

Viton sheet is available on ebay: https://www.ebay.com.au/itm/114571495690?hash=item1aacfe490a:g:LX0AAOSwU9xUSMC3
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Crikey Cam, the Viton sheet is cheap enough but the postage to Australia, and import duty, add a whole lot more to the price!
Cheers,
bazzee
 
Blimey, I didn't notice the postage and customs charges.

I have an idea though. A sheet of 2mm viton, 200 x 200 (the smallest size they sell is enough for about 900 choke plunger seals. So if someone in the UK buys a piece (local postage only) and cuts it into smaller pieces, they could post envelope sized pieces to Australia (obviously with some cost sharing arrangement) for the cost of a letter, and it won't bother Australian customs. A normal letter envelope is wider than 100mm, so cutting the sheet into 4 x 100mm square bits will be enough for 4 people. Actually more than enough. You could punch out over 200 choke seals from a piece that size!

I could certainly use some. I've used inner tube rubber before and it works OK but isn't as fuel resistant as viton. You have to replace it periodically.

I jujst checked the choke plungers on my Guzzi. The choke sealing rubbers are knackered. They're worn almost all the way through. So I hooked them out with a sharp pick. They were so fragile they fell apart. The rubber sheet I have on hand is only 1mm thick so I punched out 4 disks and put 2 in each plunger. They fit nicely.

BTW, it's a 1/4" wad punch you need. The original rubbers are 6.5mm dia x 2.7 thick, and they are held in place by a lip around the edge of the recess in the brass plunger. 2mm thickness fills the hole nicely, so I don't reckon the reduced thickness will be an issue. You can get 3mm thick viton but it won't go all the way past the lip so will probably not sit flat.

I have another 5 Dellortos on various bikes that could be in similar condition. I probably should have a look at them too.

Is anyone in UK interested in being a viton rubber sheet buyer?

Edit: I just added a drawing in case someone wants to make their own choke plunger.
 

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Great information Cam, when I looked at the plungers, they did not have anything like the indentation on your pictures,
only one had a distinct 'ring' mark but barely visible, so I am hoping that fixing the free length will improve things,
 
mauricejota7604 said:
Check the float heights !!!!!
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Geez good to see you are finally listening MT… amazing how many “issues” with Dellorto’s can be solved by setting the bloody float heights proper… but being that am no expert what would I know 🤔

Choke plungers are cheap why would you want to try to remake the rubbers crazy 😜 and if set up and adjusted proper they will last for years and years…
 
I did notice a couple of years ago that the old brass Choke plungers and the new silver choke plungers original from Dellorto are not the same length any more had the cable to short after changing plunges problem. its about 1.5 to 2 mm but you have to sit them on a flat surface and get eyeball in line to see it
 
So ... I can get a 200 x 200 piece of 2mm thick Viton from the Aussie supplier (Reglin Rubber) that Chris referred to above for $70.85 inc postage to my address. It's evidently not cheap stuff.

There's no way I need a piece that big (it'll do about 900 choke piston rubbers!), but I'm happy to get it and chop it into smaller bits for anyone who wants some.

Based on the above material cost and Australia Post rates, prices including postage and handling would be:
100mm square - $21 within Australia, $24 outside Australia
50mm square - $7 within Australia, $10 outside Australia
(postage costs assume I can post them in normal letter envelopes)

Depending how accurate you are with a 1/4" wad punch, you'll get about 50 choke rubbers out of a 50mm square and 200 out of a 100mm square.

I don't really want to go into the parts business, but I suppose I could punch out individual choke rubbers for those who don't own a wad punch and/or hammer, but I'd add a labour component. Let's say $1 per rubber + postage. That should cover my farting about and whinging time, plus a zip lock bag to put them in. Still way cheaper than buying new choke plungers.

I just checked - Prices vary a bit depending where you get them, but choke plungers are about $10 each + postage. I know that's only peanuts, but if you own a bunch of Italian bikes like I do (13 dellorto carbs at last count) and need a good handful of choke plungers, the $$ can mount up.

If there's enough interest I'll buy the 200mm square and mail bits to whoever wants some.
 
Dellortoman said:
So ... I can get a 200 x 200 piece of 2mm thick Viton from the Aussie supplier (Reglin Rubber) that Chris referred to above for $70.85 inc postage to my address. It's evidently not cheap stuff.

There's no way I need a piece that big (it'll do about 900 choke piston rubbers!), but I'm happy to get it and chop it into smaller bits for anyone who wants some.

Based on the above material cost and Australia Post rates, prices including postage and handling would be:
100mm square - $21 within Australia, $24 outside Australia
50mm square - $7 within Australia, $10 outside Australia
(postage costs assume I can post them in normal letter envelopes)

Depending how accurate you are with a 1/4" wad punch, you'll get about 50 choke rubbers out of a 50mm square and 200 out of a 100mm square.

I don't really want to go into the parts business, but I suppose I could punch out individual choke rubbers for those who don't own a wad punch and/or hammer, but I'd add a labour component. Let's say $1 per rubber + postage. That should cover my farting about and whinging time, plus a zip lock bag to put them in. Still way cheaper than buying new choke plungers.

I just checked - Prices vary a bit depending where you get them, but choke plungers are about $10 each + postage. I know that's only peanuts, but if you own a bunch of Italian bikes like I do (13 dellorto carbs at last count) and need a good handful of choke plungers, the $$ can mount up.

If there's enough interest I'll buy the 200mm square and mail bits to whoever wants some.
Click to expand...
I had a go at this once. Trouble had was the rubber I got was not flat Smith enough on the face so did not seal well. Best of luck
 
Dellortoman said:
So ... I can get a 200 x 200 piece of 2mm thick Viton from the Aussie supplier (Reglin Rubber) that Chris referred to above for $70.85 inc postage to my address. It's evidently not cheap stuff.

There's no way I need a piece that big (it'll do about 900 choke piston rubbers!), but I'm happy to get it and chop it into smaller bits for anyone who wants some.

Based on the above material cost and Australia Post rates, prices including postage and handling would be:
100mm square - $21 within Australia, $24 outside Australia
50mm square - $7 within Australia, $10 outside Australia
(postage costs assume I can post them in normal letter envelopes)

Depending how accurate you are with a 1/4" wad punch, you'll get about 50 choke rubbers out of a 50mm square and 200 out of a 100mm square.

I don't really want to go into the parts business, but I suppose I could punch out individual choke rubbers for those who don't own a wad punch and/or hammer, but I'd add a labour component. Let's say $1 per rubber + postage. That should cover my farting about and whinging time, plus a zip lock bag to put them in. Still way cheaper than buying new choke plungers.

I just checked - Prices vary a bit depending where you get them, but choke plungers are about $10 each + postage. I know that's only peanuts, but if you own a bunch of Italian bikes like I do (13 dellorto carbs at last count) and need a good handful of choke plungers, the $$ can mount up.

If there's enough interest I'll buy the 200mm square and mail bits to whoever wants some.
Click to expand...
 
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