Final drive vs. model year

[latexeses]

I may have over looked the answer to this question. Please forgive the repitition if I have.

When choosing a 750/850 final dive unit for the swap, does the year of the donor bike make a difference???

I am working on a 79SF. Would it be ok to look at 750/850 80-81 final drives.

I have an 81 850 close by that might be a good candidate for the swap but I don't need anymore useless parts laying around...

Thanks for the help.

[tarzan]

1j7y0

Both 750 and 850 are the same.It should say 1J7Y0 on it.

[TopCatGr58]

Hey Latex,

They will all bolt on just fine. I don't think there were any ratio changes with the later models of the 850. But you could look up the specs on the Yamaha site for the 750 and 850 to compare. Perhaps others will chime in with more definitive info, I haven't done the mod myself, I like to REV!!
T.C.

[red bandit]

I've got an 850 on mine, it's the same ratio as the 750.

[latexeses]

Thanks for the info.

TC..
I am with you about the revs. Nothing sounds better than a tuned XS running through the R's. It's just that I am working on a F and an SF and was thinking doing the swap on one or the other to see how I liked the change. Looks like the SF will be done WAY before the the F in finished.
What I was concerned about was the possible differences between the later 750/850's mating up ok with the early model F & SF's.

Tarzan..
Thanks for the info on the part number. I'll check.

[bikerphil]

fd swap

Hey lateXeses, I've done the swap to both my Standard and Special. I did my Special first and it's fun as sh!t to ride now. It still winds nicely but not nearly as much as before. Now on the Standard it makes a huge difference on the highway and just cruising 'round town. It takes a little getting used to off launch, but not really any problem. I like them both with the swap and they'll both stay that way. Ace Hardware has the perfect bronze spacers for the driveshaft, about $3.50 apiece. Good luck!

[latexeses]

Hey Phil...
You just generated another question. Is first gear a little taller in the standard or is it just the larger rear wheel size?

[bikerphil]

Hey Phil...
You just generated another question. Is first gear a little taller in the standard or is it just the larger rear wheel size?

The transmissions are the same in both Special & Standard. It's just the 17" RW that makes the Standard feel more like a cruiser.

[DELL82]

Where are the pictures

where can I see the FINAL DRIVE MOD with pictures. The ones in the archives have moved.
dell82

[bikerphil]

This should be the link....

http://www.xs11.com/index.php/xs11-i...usive-6th-gear

[DELL82]

bikerphil. I just bought, on E-Bay, a '79 750 final drive item #250306989140 for $28.95 including shipping and got it today.
Problem is it does not have the correct number on it, 1j7y0. Where is this number?
On the wheel side of the final drive the cast in number is 2H700 and the ration is 3 1/4 turns of the pinion to one for the wheel, is this right? Any help will be grateful
Dell82

[Jerry]

Sounds like they shipped you an XS11 final drive. Ratio is 3.3 to 1. The 750/850 ratio is 2.9 to 1. The 2H7 is a part number prefix for the '78 XS11, but the rear diff was used throughout the XS - XJ 1100 series. Only difference is color, some are black and some are silver. IIRC, the number should be on the bottom of the casting, toward the wheel side.

[DELL82]

thanks Jerry. I am sending the seller a message and will wait for a reply. Definitely do not need another 1100 drive.
Dell82