1981H xs1100 rebuild project, started Feb.2017

[motoman]

Thanks Ray! I actually learned some better specifics from your two added threads, so.........it wasn't a wasted day for me.

[3Phase]

Right on, Frank! Way to go, man! It's alive! Alive!

[Jeffintampa]

while you in the tear down mode lol

I think I would recommend you also pulling the valve cover and checking your clearances, very easy to check. They adjust by changing to thicker or thinner disks.

[skids]

I think I would recommend you also pulling the valve cover and checking your clearances, very easy to check. They adjust by changing to thicker or thinner disks.

While I agree that valve clearances should be periodically checked, if his issues only occur in the rain, I doubt that this is the problem with his bike.

[Jeffintampa]

While I agree that valve clearances should be periodically checked, if his issues only occur in the rain, I doubt that this is the problem with his bike.

Oh I though he was getting a cheap ole on going.

[FranksBMW]

Oh I though he was getting a cheap ole on going.

I am. Skids must have my thread confused with another.

[FranksBMW]

My gas tank is currently de-rusting via electrolysis. Then a few holes need welding up. Moving along on the journey.

[MaximPhil]

Hi Frank,
Glad to hear you are making progress. This variable weather has to have you in and out like a fiddlers elbow of your garage/shed.
Phil

[FranksBMW]

Tank was derusted by reverse electrolysis, and my buddy TIG welded up the holes. One Venturer tank saved. Still have to coat and seal the inside.

[TopCatGr58]

There is something fairly large and loose rattling inside the mufflers, so they will eventually need to be replaced, like the ripped seat, but that can wait until the bike is running.

Hey Frank,

I couldn't find these photos a few days ago when you posted this, but I finally found them, and so wanted to show you that the mufflers are actually quite complicated and there's a good chance something may have come loose inside there! Take a look! I think CZ sent them to me, but can't recall for sure....so if I've made a faux paux...please forgive me.








T.C.

[FranksBMW]

Cool, thanks TopCat!

My rattly exhaust actually didn't sound too bad while it was running briefly.

[CaptonZap]

I think CZ sent them to me, but can't recall for sure....so if I've made a faux paux...please forgive me.

[


T.C.

Yeah, that was a few years ago, so no big deal to space it out.

For those with an interest, I will explain the flow.
The two bulkheads are spot welded to a sheet metal shroud, which is the inserted into the outer shell and rosette welded to it. You can see the weld on the ear sticking up on the left bulkhead. The ear is part of the inner shroud. You can see the rust between it and the outer shell back at the right bulkhead. Most rust forms between the shroud and the shell, which comes from short trips in moist weather, during which the moisture between the two is not evaporated.

The exhaust gas pulse comes in from the left, and is aimed it the stub tube welded to the two long lower tubes. The sound wave is reflected back up the header pipe, and I assume that the factory designed it to produce some reversion during valve overlap. The gases hit the left hand bulkhead, and reverse direction so that they can flow through the four long tubes, into the far right anti chamber, where they again reverse direction and flow through the oval hole in the right hand bulkhead. They then flow through the holes in the center tube, which is the one sticking out the rear of the muffler. Some folks will drill holes in the plate supporting the center tube, which relieves a little back pressure, and increases the sound level.

These where from an 80 Standard, which was a demonstrator bike for a dealer, and thus presumably subjected to a lot of short trips, which never fully heated the mufflers up, allowing the rust to get to the stage it is. Oddly enough, the front half of the mufflers where just fine, and received grafts of sectioned Sportster mufflers.

CZ

[FranksBMW]

Sanded my newly welded gas tank today in preparation for black rattle can paint tomorrow. This tank does not have the gas cap hardware, but I have a line on another tank that that does. Took apart and cleaned the petcocks and cleaned up the fuel level sensor. I obtained a headlight bucket recently and will soon install it (after soon replacing the ignition unit with a key). I'm surprised that Yamaha Canada could not supply me a key or even a key code, given the code on the original ignition unit.

I'm worried about the electrical connections - wiring isn't my thing, but I'll learn. This bike had a windjammer-like fairing and a wiring loom that I won't be using. I will keep it though in case I or the next owner wants to reinstall the fairing.

[FranksBMW]

By "wiring loom", I mean pigtail.

[FranksBMW]

Airbox "reinserted" into its place with a new air filter. Boy, what a goofy design for how it's held together. Silly little bushings too, just to add complexity. Going to wait for warmer temps (more flexible boots) to install the carbs.