TS250 Joy, Then Sadness

[VinceDrake]

Hey Weld!

I've been around, I just didn't have anything to say that hadn't already been said better...

The quads are a whole 'nother post... Probably bore everyone to death.

Suddenly there was a post I could be at least somewhat helpful in!

But back to the subject at hand, had a previous owner stuck a stock piston in an oversized hole, you would hear it. It would evidence itself as piston slap-- That much would sound like a collapsed lifter in an old Oldsmobile.

But even before that, it would be a real pain in the sphinkter to start.

My reasoning being-- compression means nothing to an old Smoker. Well, not much at least. What is critical is vacuum. I.e. the rings have to be able to seal well enough to a: draw fuel into the crankcase, and then b: seal well enough to force it over the transfer ports. Oversized holes and ruined piston/rings usually first manifest in a bike that is a bear to start. They just can't draw and transfer a wet enough mixture with the kicker to light up. Sometimes electro-start would help cover a worn engine, but not a kick-only horse.

Sometimes on really old dollies, we would push them around in gear at speed, just to generate enough vac to light up.

With some attention to detail, outer crank bearings can be changes with the help of your deep freeze, and your oven. It's the centre bearing that's a real bear.

In my experience, it's almost always the drive-side bearing. A lot of old dollies were double bearings on the drive side to handle the load created by the primary drive. I don't think I ever saw a gen. side bearing barf, except from rust pitting, etc.

Regardless, with the way that piston grenaded, the crankcase should really come apart to clean it out properly. I lot have guys have tried rinsing them out with WD40, etc, but I am paranoid about little bits of aluminum floating around in there, borking up the cylendar bore, piston skirts, etc.

Wow, that's 2 really, really long posts, only vaguely related to the subject material at hand! My bad!

--Vince
(Who always wanted an old TS!)

[katoranger]

I am learning much about 2 strokes.

VD, weren't you trying to import a trabbi?

[VinceDrake]

Yup, trabbi is on my list of thing to own before I die. Sadly though, at this point in time, The import costs are more than the car costs...

I'm kinda going with the theory, eventually I will find one that someone has gotten disgusted with, and pick it up...

It's been working so far with China-atv's!

--Vince

[katoranger]

I did see one while I was in GA. On old German guy pulled up in a vintage mercedes van. He worked on german cars. He had one.

[VinceDrake]

Did he look like the type of guy who gives up easy?

[katoranger]

I don't know if it was for sale. He was an older gentleman.

[Weldangrind]

This is a very old thread resurrection. I'm rebuilding the bike for my neighbour, so we can ride together. My goal is completion by August.

I found a broken motor mount when I pulled the bottom end. Here's the broken mount and the beginnings of a replacement:



Here's the donor material:



I took the weld-on nuts from the broken mount and welded them onto the new mount:

[Weldangrind]

This is the mount mocked up; I'll paint it before the motor goes in:



The front tank mount was cracked. I welded it back on.

[Weldangrind]

The seat pan was really bad. These are before shots:





This is after some electrolytic de-rusting:



After the rust removal, some of the metal was quite pitted and thin:



I chopped it out and welded in new steel:

[Weldangrind]

I also welded some steel to the top side of the pan to add strength and then primed it. I'll probably coat it with Plastidip, since I have some on hand. I'm hoping that several coats will keep rust at bay. I'm considering wrapping the foam in plastic so it won't absorb moisture and ruin the pan again. Does anyone have thoughts on that?


The rear shocks were terribly rusty, so I dismantled them. I cleaned the chrome coils with SOS pads and worked the shock bodies on the bench grinder wire wheel. The shock bodies got a coat of primer and Rustoleum semi-gloss black; I'll reassemble them and take pics soon. Same with the footpegs.

[franque]

If that's a bed frame, apparently they don't like being welded, as they're spring steel, the heat makes the steel really brittle. If it's mild steel, disregard, but spring steel needs special attention for welds that don't immediately break. What did you figure out with the engine?

[JerryHawk250]

Looks good so far W&G. That seat pan looks rough but who will know once covered.

[Weldangrind]

Originally Posted by franque

If that's a bed frame, apparently they don't like being welded, as they're spring steel, the heat makes the steel really brittle. If it's mild steel, disregard, but spring steel needs special attention for welds that don't immediately break. What did you figure out with the engine?

That's exactly what I was thinking; I've heard that bed frame is brittle due to the high carbon content, but I don't actually know what I'm saying. It sure behaved like mild steel, so I'm gonna call it a win.
One of the crank bearings is pooched. I've installed new bearings in the transmission and I have new bearings on hand for the crank (along with a new wristpin bearing for good measure). Some assembly is now required.

[Weldangrind]

Originally Posted by JerryHawk250

Looks good so far W&G. That seat pan looks rough but who will know once covered.

Yeah, the new cover will hide many sins. I was looking it over today and might yet do some more reinforcing before I cover it.

[Megadan]

Originally Posted by franque

If that's a bed frame, apparently they don't like being welded, as they're spring steel, the heat makes the steel really brittle. If it's mild steel, disregard, but spring steel needs special attention for welds that don't immediately break. What did you figure out with the engine?

High carbon spring steel needs to be pre-heated to avoid thermal stress fractures caused by expansion along the weld seam. Very similar to how you have to weld cast iron actually, except high carbon steel is a lot less picky on the cool down.