Just Another Restore Thread...

[TruthHammer]

I already introduced myself and my bike here, and now it's time to get to work on it. It needs a lot of work, and I'll need a lot of help. So I thought I should just start a new thread in the right forum.

So first step... Clean it up and figure out what I've actually got along the way. Like I said before, it's a 79 SF frame (3H3), but the engine plate shows 81 SH (4R0).

I'm working my way through the carb removal section in my Clymer, and I want to understand what I'm doing, not just starting blindly following instructions. So here's my first total newb question... It says when removing the gas tank I should set the petcocks to 'on' or 'res' before pulling the vacuum and fuel lines. Why not 'off'? Also, do I need to drain the tank before removing it? Any other advice before diving into it?

Are the SF & SH carbs different? Not sure which might be on my bike. (Hopefully not a 3rd donor vehicle.) Once I get the carbs off, I'll post pics to try to figure out which carbs I've got and get some advice before digging into them.

Thanks!

[MaximPhil]

Hi Hammer,
You have what is affectionately known as a FrankenBike
You will need to determine which carbs have been used as there are about 4 configurations from memory. You want all 4 to be the same generation. Add to your signature what you have as in the future if you run into a problem it is critical to getting the correct answer. Check the rest of the ignition parts match to 4RO 1981 spec.
Petcock has three settings Prime flows all the time so avoid that one when you disconnect the hose. I am not sure how a Special works as I have a Standard
You are off to a good start.
Phil

[red bandit]

Putting the petcocks to "on or res" is referring to the standard tank/petcocks. On the special tank turn it to off. IIRC. No need to drain the tank.

[jetmechmarty]

SF and SH have different carburetors. The first sign of the earlier carbs is aluminum tops. The later ones are chrome steel. SF carbs have brass floats. SH carbs have plastic ones. In '81, I believe the carburetors have a drain nipple on the float bowl. '80 and earlier have a bolt.

Any of them will work fine, but you have to know what they are because the set-up is different.


SF


SH

[jetmechmarty]

If this is your bike, it looks to me like it is a 1981 XS1100SH. I see more SH than SF. The seat and grab rail lead me to believe the frame may be SH. I definitely see parts from the earlier bike, but how much?


If the frame is SF, the original seat is real nice.

[TruthHammer]

If this is your bike, it looks to me like it is a 1981 XS1100SH. I see more SH than SF. The seat and grab rail lead me to believe the frame may be SH. I definitely see parts from the earlier bike, but how much?


If the frame is SF, the original seat is real nice.

Yep, that's mine.

The frame is stamped 3H3, so unless they doctored it somehow (which wouldn't completely surprise me ) it is a SF. Will the SH seat and grab bar not fit on the SF frame?

[jetmechmarty]

Yep, that's mine.

The frame is stamped 3H3, so unless they doctored it somehow (which wouldn't completely surprise me ) it is a SF. Will the SH seat and grab bar not fit on the SF frame?

I didn't think so, but never tried it. I knew the seat fit, but hits the side covers.
The SF is the best looking of the bunch, IMHO. I wouldn't want to change it.

[TruthHammer]

Carbs are off, and I'm feeling pretty accomplished tonight.



The broken vacuum line on the left here might be why it was bogging at high RPM.


Thanks for the knowledge, guys. I'll crack into it this weekend if not sooner and let you all know what I find.

[bikerphil]

Keep the parts from each carb seperate, don't mix them up.

The emulsion tubes in 2+3 are different than 1+4

[motoman]

From the valve cover and cyls. being blackened, ignition cover circular recess, along with the style/location of rear peg retainers, a nice lookin' 81Special.

[Eveready1100]

But it's a 3H3? That's '79

[motoman]

But it's a 3H3? That's '79

Tis' a 79frame, not motor. motor is an 81yr. model.

[bikerphil]

The carbs are 79, be sure to use the jetting and float height specs for the 79 early type carbs.

[TruthHammer]

The carbs are 79, be sure to use the jetting and float height specs for the 79 early type carbs.

What gave it away for you?

[jetmechmarty]

SF and SH have different carburetors. The first sign of the earlier carbs is aluminum tops. The later ones are chrome steel.

BikerPhil is your go to guy!