Carb diaphragm replacement question

[bobber]

I just purchased new diaphragms for my 93 Venture and noted after pulling the slides out that there is a small hole in the bottom of the slide that sits at the six o'clock position when installed in the carb. The diaphragm tab sits at the 1 o'clock position. My question: "Is it important to install the new diaphragms onto the old slides in the exact same position (small hole in the slide sits at 6 o'clock and the diaphragm tab at 1 o'clock)?? Seems like I would have to be precise.

Any assistance would be appreciated.

Thanks

Bobber

[zagger]

I just purchased new diaphragms for my 93 Venture and noted after pulling the slides out that there is a small hole in the bottom of the slide that sits at the six o'clock position when installed in the carb. The diaphragm tab sits at the 1 o'clock position. My question: "Is it important to install the new diaphragms onto the old slides in the exact same position (small hole in the slide sits at 6 o'clock and the diaphragm tab at 1 o'clock)?? Seems like I would have to be precise.

Any assistance would be appreciated.

Thanks

Bobber

 

Hey Bobber,

I think that you should find a tab on the diaphragm which must be aligned with a slot on the carb body. I don't recall if there is anything that forces the slide to be in any particular position relative to the diaphragm, but the little hole is supposed to be at the bottom - sort of a drain hole, I guess. I would just try to copy the original orientation of the parts.

zag

[bobber]

Thanks for the reply Zag. This is my first time replacing diaphragms so I wanted to get it right the first time. I'm not sure but I would bet there is no adjustment of the new diaphragm once its installed on the old slide. Every slide was the same with the little hole being at the bottom (6 o'clock) so its likely that's the way its supposed to be.

Bobber

[Marcarl]

Yep, down at the bottom, somewhere near close.

[CaseyJ955]

They are mating and wear surfaces so I felt it was prudent to go ahead and index them in just as they came out, they are clocked as they were removed. Not sure if it's really necessary, but why not slide them in just as they came out? You should be able to carefully rotate the diaphragm after it's installed on the slide but I would get it close. I had some that rotated more easily than others. I used some WD-40 to help them on and into position. I got mine spot on to the naked eye, however precise that turns out to be I'm not sure but it seems to be doing it's job quite well.

 

Not sure it makes much difference but I used the diaphragms that are made in the UK and sold on Ebay. Well made, pretty happy with them. The OEM ones were to rich for my blood and the Chinese ones are Chinese.

 

If after the diaphragms are indexed, cleaned and reinstalled, and there is any stiffness or binding in the slides take a look at the needles to make sure they are true. Even if they are a little too tight they can cause slight binding of the slide. They need only be barely snug. Handle carefully, these slides can be brittle.

[bobber]

They are mating and wear surfaces so I felt it was prudent to go ahead and index them in just as they came out, they are clocked as they were removed. Not sure if it's really necessary, but why not slide them in just as they came out? You should be able to carefully rotate the diaphragm after it's installed on the slide but I would get it close. I had some that rotated more easily than others. I used some WD-40 to help them on and into position. I got mine spot on to the naked eye, however precise that turns out to be I'm not sure but it seems to be doing it's job quite well.

 

Not sure it makes much difference but I used the diaphragms that are made in the UK and sold on Ebay. Well made, pretty happy with them. The OEM ones were to rich for my blood and the Chinese ones are Chinese.

 

If after the diaphragms are indexed, cleaned and reinstalled, and there is any stiffness or binding in the slides take a look at the needles to make sure they are true. Even if they are a little too tight they can cause slight binding of the slide. They need only be barely snug. Handle carefully, these slides can be brittle.

 

I got my diaphragms out of Britain also. They seem like pretty good quality and others on this site have vouched for them. I will go ahead with lining everything up as suggested as a little more time and effort will likely pay off. I still have a bit of wait before I can ride again anyway...Canadian winters tend to hang around!

Thanks again for the reply.

Bobber

[Patch]

Hey Bobber,

 

There is a reason for the hole being at thee bottom of the piston. It is a calibration for the slide. The spring is also such a calibration.

The metering needle divides air flow and the piston is at the venturi this has to do with velocity.

Anyways I see yo're are an AB. fellow let me know if I can help.

[jfman]

Are we supposed to glue the diaphragms on or glue the metal sleeve to the plastic piston?

 

I installed new diaphragms and the metal sleeves seem to snap right into the plastic piston and hold fine but I am wondering if I was not supposed tu use glue or sealant to permanently hold it together.

 

BTW I ordered the diaphragms from china at 5$ each on fleabay. I have yet to ride the bike but am happy with the fit.

[Marcarl]

No glue needed or wanted, it will distort the diaphram. Seeing as you got them from China, be prepared to replace them soon, so if you discover issues again, check them for problems first.