Carburetor diaphragm won't come out

[Joes_ol80]

I made my first attempt at rebuilding a carburetor and I've been humbled. The diaphragm won't come out on either one, although one will twist and to be completely honest I can't make heads nor tails of any of this stuff. If anyone has any knowledge around this, heck if anyone's in the Phoenix area and wants to see what I'm working with, anythings appreciated because I think I overestimated myself and I can't figure this thing out.

 

[gggGary]

Lets see a pic or two?
When you say diaphragm you mean the piston will not come up and out?
Heat is your friend, warm the bottom of the piston with a hair dryer through the intake bell.
Usually once quite warm the varnish that's' holding it softens and lets go of it. Some rust buster or mineral spirits will help the heat loosen the varnish.

 

[650Skull]

https://www.xs650.com/threads/xs650...workshop-manuals-and-other-information.30569/

From the link above......in Post #7

https://www.xs650.com/threads/tentative-carb-id-layout.43392/

Post #9 is an excellent Write up on Carbs. From Suzuki but relate to our CV carbs.

 

[toglhot]

I take it you mean the diaphragm won'tcome off the slide. OEM diaphragms are not available by themselves, however, you can buy a slide and diaphragm, but they are a little pricy, in Oz at least.

JBM Industries sell a diaphragm, but it isn't the same as the original and also doesn't fit the same as the original. First you have to remove the old one by cutting the plastic ring off. There is a very thin ally overhang on top of the slide, you have to be careful not to damage it as the JBM relies on that to stop the diaphragm from sliding off the top. The JBM diaphragm is a snug fit over the top of the slide but has to be glued to stop the slide from rotating.

I never went down that road as the slide and diaphragm from the UK were $130 each, plus postage, in Oz, and at the time JBM weren't shipping to Oz.

I did play trying to get a diaphragm off a spare set of carbs I had, but found it very difficult. Memory is a little sketchy now, but from memory I used a rotary tool to remove the top plastic ring, that is all I can remember.

JBM are a good source for manifolds and diaphragms BTW, and resident in the US.

i converted to VMs and the two sets of BS38s I had went straight in the bin - where they belong.

Google it, there is all sorts of info available on the web for XS650s.

 

[650Skull]

I take it you mean the diaphragm won'tcome off the slide. OEM diaphragms are not available by themselves, however, you can buy a slide and diaphragm, but they are a little pricy, in Oz at least.

JBM Industries sell a diaphragm, but it isn't the same as the original and also doesn't fit the same as the original. First you have to remove the old one by cutting the plastic ring off. There is a very thin ally overhang on top of the slide, you have to be careful not to damage it as the JBM relies on that to stop the diaphragm from sliding off the top. The JBM diaphragm is a snug fit over the top of the slide but has to be glued to stop the slide from rotating.

I never went down that road as the slide and diaphragm from the UK were $130 each, plus postage, in Oz, and at the time JBM weren't shipping to Oz.

I did play trying to get a diaphragm off a spare set of carbs I had, but found it very difficult. Memory is a little sketchy now, but from memory I used a rotary tool to remove the top plastic ring, that is all I can remember.

JBM are a good source for manifolds and diaphragms BTW, and resident in the US.

i converted to VMs and the two sets of BS38s I had went straight in the bin - where they belong.

Google it, there is all sorts of info available on the web for XS650s.

@Joes_ol80
$20 US + postage, slide and diaphragm. For BS34's 80-83/4

https://www.cruzinimage.net/2018/07/23/80-83-yamaha-xs650-carburetor-slide-piston-rubber-diaphragm/

Link to JBM Industries CV Diaphragms. Do read all the required literature. Go to the homepage for more info.

http://jbmindustries.com/Dimensions.html

 

[Joes_ol80]

The diaphragm is in the first picture and also there is a lot of this black liquid leaking from the carburetor. I don't know what it is, I'm inclined to think that it's not motor oil since the last I checked the oil the bike is running is blue. But it's gotten on the diaphragm and they are drying out a little, so if anyone knows of anything that can preserve these, id really rather not have to replace them.

 

[gggGary]

Prolly gasket sealer permatex used in the fuel system somewheres or cheezy tank sealer will do that too.
Red grease or silglide on the diaphragms.

 

[jetmechmarty]

WD40 should work to free it up. I use Parker O-Lube to preserve the diaphragm.

https://www.aircraftspruce.com/catalog/cspages/parkerolube.php You can also find it elsewhere, including Amazon.

@5twins recommends red rubber grease. I'm sure that's fine as well.

 

[Joes_ol80]

I'm wondering if anyone knows the part number for intake boots on a 1980. I've been looking but I haven't found nothing yet

 

[jetmechmarty]

I'm wondering if anyone knows the part number for intake boots on a 1980. I've been looking but I haven't found nothing yet

I looked. George Fix, S.C.I., MikesXS all no stock. Niche Cycle has them, but lists fitment as 1975-1983, so I wouldn’t buy those.



If you get desperate enough, I probably have functional used ones.

 

[Jan_P]

Maybe there for numbers

https://www.mikesxs.net/yamaha-xs650-carb-holders-set-2-80-84-bs34-cv-oem-3g1-13586-3g1-13596.html

 

[GLJ]

Part #s and years.
I bought a set from Niche for a 81 and they seem to be ok.

 

[650Skull]

Do a little exploring when a suppliers link is posted. Sure, Cruzinimage is from Japan but their prices can't b matched.

The part no is for 80 -83 BS34's.
(Does include saying will fit for 78 and 79 Specials)

https://www.cruzinimage.net/2017/10...carb-intake-manifold-set-insulator-2-intakes/
Replaces Yamaha P/N:
3G1-13586-00-00:LH X 1
3G1-13596-00-00:RH X 1

This is worse from Niche Cycles. Very poor, supposed to b a suppier who knows what they are selling.

Can certainly see why people would have no idea, get confused and possibly end up buying what the don't want.

http://www.nichecycle.com/ncs/categ...-carburetor-flange-set-left-right-by-ncs.html