79sf Vacuum Diaphragms

[Shuriken]

I've noticed on EBay the new vacuum diaphragm assemblies being sold for various XS models.

Problem is, I've never seen anything for the 79sf. Are the diaphragm assemblies for it different mm size or something like that?

I sure would like a new set but am wondering what's the best route to go.

Ben

[DiverRay]

Ben;
The 79SF is the same as the 78 and 79 standard. Just look for the 78/79 XSEleven diaphrams. You may want to check and verify that you still have the proper carbs. The 80 up are different as they don't have the same needles.
Part # for 78/79 2F3-14040-00-00
Part # for 80 3H5-14040-00-00
Ray

[Shuriken]

Good idea. I remember swapping the carbs, but I think the swap was between 78 and 79.

Ben

[ccogswel]

You can check out BikeBandit.com.

I was looking the other day under the OEM search. Click the Carburator tab. There is a exploded view of the carbs. They show what has been discontinued and what I believe may still be able to get. They list part# 21390-001 for $134.52 You can check it out if you want. Hope this helps.

[Shuriken]

Several years ago I tried to spend $450+ on new assemblies from BikeBandit. They never shipped. Probably a good thing, that's a HIGH price for 'em.

Now though, with a bit more income, a new set sure would be nice. Plus, I've ordered half a dozen times from BB lately and they are FAST and surprise me with what they can get. I got an OEM fuel petcock for a 73 Suzuki, for one.

Ben

[TopCatGr58]

Hey there Ben,

Regrettably, the 78-79 carb slides don't interchange with the 81's! I just went to the garage, and put a caliper on both of the slides, and the 81's are almost a 1.5mm larger diameter than the 79! Too bad, cause you can get the 81 series for $64.95 from MikesXS!

BTW, the proper Yam # is:
79SF vaccum slides: 2F3-14940-00-00

If you'll go to www.cycle-parts.com, do a search for the above #, you'll find them for $120.40 ea, a bit cheaper than BB!
T.C.

[Winterhawk]

I saw a box of good used Diaphrams at Merriam Cycle But who could ever guess how much they would be. I know he has new ones but don't know how much.

[Shuriken]

Well, it's interesting to think about the size differences. I personally like the older carbs. I can adjust everything, even the jet needles. On my former 80g carbs, I couldn't fiddle as much but could find replacement parts.

I guess that's the trade off. Why would the 79's be smaller?

Why would smaller/earlier diaphragms go for twice the cost?

Ben

[TopCatGr58]

Well, Ben,

As for the increased cost of the older ones, I would think it's because they are more complicated, with the adjustable needles, perhaps a few more parts vs. the newer ones!?

Couldn't tell you why Yamaha changed the design, not a carb guru! Don't know if the larger/wider slide would rise slower or faster? Probably something to do with emissions!?
T.C.