VIN & Exchangeable parts

[Hawkinspickle]

Hi folks,
I'm new to the forum and new to older Yamaha's. Happy to be here. Just bought a 1979 XS1100, …I think. I say I think because my registration papers say it’s a ‘78 but what I’ve read on line I think it’s the ‘79 special as I noted above. I can’t seem to decode the 9 digit VIN. My VIN is 3H4-000721. Can anyone please confirm my findings?
Also, I am looking to buy some headers and exhaust on eBay but they are from a 78. Does any know if the 78s and 79s exchange this part or most others? Thanks.
Dan.

[LenB]

Check out https://xs11.club/forum/miscellaneou...identification 3H4 shows up as a Canadian '79 Special. Majority of parts, from my experience, are common from '78 to '81, based on the model (Special/Standard). This can be verified by checking out any seller's parts fiche. e.g. https://www.yamahapartshouse.com/oem...-xs1100f-parts and comparing part #'s vs. production years.

[Ranger_xs1100]

Welcome to the forum Dan,

Here's a lot of great info from Crazy Steve regarding exhaust interchange:

Interchange Guide: Exhausts, Footpegs - XS11.club Forums

Good luck,
Bob

[DiverRay]

Welcome! Some of the body parts, seat, side covers, grab bar, are ONE year only! You have an early VIN, so it was probably sold late '78, and registered as a '78 and not the '79 model it is. Do check with andreas, a member here who breaks bikes and knows the XS1100 well. He is located in Canada, just north of the Idaho border. I know from experience that you cannot put a standard exhaust on a special without some mods. Most aftermarket exhaust, however, will fit either machine.

[Hawkinspickle]

Thanks everyone for the information and the excellent resources. Never belonged to an online club before but always creeped various public forum discussions and found them to be very helpful. I can now say that I am the owner of a 1979 XS1100SF; thanks Len.
I just got outbid by a guy on eBay on some headers and aftermarket exhaust. But after reading some the info provided by you folks, maybe it was a good thing as they may not have fit my bike. My apologies if it was of you guys who I was bidding against and drove up the price a few bucks.
I have tons to learn about these bikes but motivated to do so cause they’re super cool.
Dan

[jetmechmarty]

Check out https://xs11.club/forum/miscellaneou...identification 3H4 shows up as a Canadian '79 Special. Majority of parts, from my experience, are common from '78 to '81, based on the model (Special/Standard). This can be verified by checking out any seller's parts fiche. e.g. https://www.yamahapartshouse.com/oem...-xs1100f-parts and comparing part #'s vs. production years.

The XS1100SF parts fiche is no longer available. That's the 1979 Special. It has differences from the 80/81 Specials.

[Hawkinspickle]

The XS1100SF parts fiche is no longer available. That's the 1979 Special. It has differences from the 80/81 Specials.

A quick glance at the fiche detials, in particular the rear fender, the forks and the cross-over on the exhaust, I see that these are different from my bike which is a '79 special.

[Hawkinspickle]

Hi folks,
Just confirming, would an engine from a 1980 Yamaha XS1100S (serial number 3U9-000640) bolt into my 1979 XS1100SF (3H4-000721) without issue? A very good source in this group told me that it including the electrical would work without modifications. Not wishing to second guess my friend, I just wanted to be sure before I pull the trigger on the engine purchase.
Thanks,
Dan

[red bandit]

The engine from a 80 will swap right in a 79 frame. Not sure if the 80 ignition will work with the 79 ignition but you can swap the 79 ignition on to the 80 engine.

[Hawkinspickle]

Thanks for confirming. After searching around, I found a post on this site that says the change to the ignition was in '81, just like my friend said it would. So I'm good to go.

[Hawkinspickle]

Another silly question folks: while I assume that the carbs from my '79 special will bolt with no problems to the '80 special engine, I understand that the XS11's were de-tuned a bit in the 80s. Was this "de-tuning' to meet higher emission standards done to the engine or was it done to the carbs? I guess I am wondering what I will experience, if anything, with the swap from '79 engine to the '80?
Dan

[DiverRay]

Carbs should bolt up and work, after a vacuum sync. Later carbs had a few changes, but a carb is a carb, and they all try to flow the same amount of air with the XS1100's.

[Hawkinspickle]

Carbs should bolt up and work, after a vacuum sync. Later carbs had a few changes, but a carb is a carb, and they all try to flow the same amount of air with the XS1100's.

Thanks Ray.

[Rasputin]

The XS1100SF parts fiche is no longer available. That's the 1979 Special. It has differences from the 80/81 Specials.

I have them here if anyone needs. I did send them all to TC but he disappeared shortly after. I wanted to share all the parts fiches and manuals with the group. I guess he never did the link to them.

[DiverRay]

You may be able to upload the fitch as a pdf. If so, post it in the forum/maintenance/tools section. It should then be available to everyone.