Quick diaphragm question

[luke000]

I was changing my diaphragms and noticed I needed to replace 1 carb slider. I got the new one today and it has a new diaphragm on it, however I am using the JBM style diaphragms with the thick rubber tire instead of using the 2 washers to attach it to the slider. I want to have the other JBM on my new slide so they are all the same, however I want to keep the one that came with my new slider as an extra. How would one go about removing the stock style diaphragm without destroying it? The old ones were trash and i simply cut them off.

[twigg]

I was changing my diaphragms and noticed I needed to replace 1 carb slider. I got the new one today and it has a new diaphragm on it, however I am using the JBM style diaphragms with the thick rubber tire instead of using the 2 washers to attach it to the slider. I want to have the other JBM on my new slide so they are all the same, however I want to keep the one that came with my new slider as an extra. How would one go about removing the stock style diaphragm without destroying it? The old ones were trash and i simply cut them off.

 

The stock diaphragms just pull off, iirc.

 

You might want to lubricate it well and use something blunt and thin to ease it out of the slot.

[MiCarl]

Your carburetors don't care if the diaphragms match. Why risk ruining a good one pulling it off?

 

I recommend keeping the JBM as your spare.

[luke000]

Your carburetors don't care if the diaphragms match. Why risk ruining a good one pulling it off?

 

I recommend keeping the JBM as your spare.

 

The JBM seems like its made stiffer rubber, do not think this would affect the running on that one carb to have a "softer" (for lack of a better term at the moment) sync wise? (I will be balancing them when I am done no matter what)

[saddlebum]

The JBM also does not use the nylon washers that the stock one uses. You basically have three choices.

1) My Personal preference. You cut/split the washers off then slip off the original diaphragm saving it but sacrificing the washers. Then carefully slip the JBM over the small metal lip onto the slider. Do not over stretch it.

 

2) Not my favourite choice but you can carefully remove the metal sleeve from the slider than replace it with either crazy glue or green Loctite.

 

3) Just run it with OEM diaphragm also not my favourite choice as I would prefer to have the diaphragms uniform because the JBM is a bit stiffer but works well.

[Marcarl]

I would go with all JBM, by the time you need to replace them, or do anything else to them, you'll be riding a different sort of bike.

[MiCarl]

The stiffness of the diaphragm isn't going to have much effect. If it did the replacement diaphragms would be useless. It's the spring that controls how much the slide rises.

 

If you cut away the plastic retainer the stock diaphragm won't work on it anyhow, so you won't have a spare.

[luke000]

The stiffness of the diaphragm isn't going to have much effect. If it did the replacement diaphragms would be useless. It's the spring that controls how much the slide rises.

 

If you cut away the plastic retainer the stock diaphragm won't work on it anyhow, so you won't have a spare.

 

 

Actually I do have 1 set of spare washers (from the toasted slider) but that makes sense about the spring being the contributing factor, I sorta feel stupid for not thinking of that.

[MiCarl]

I sorta feel stupid for not thinking of that.

 

Not stupid. When we get focused on a tree we can overlook the forest. Way easier to see the forest from a distance.

[greg_in_london]

If you do take the diaphragms off, I find that they're pretty tough and come out just fine, but then when they're sitting they somehow deteriorate (after being okay in all that petrol vapour for years) and sort of go gungy, with any folds sticking to each other. I might have kept mine as backup, but the idea went pearshaped. I don't know if that's just me and a sign of increasing age though...