A rider ...

[carryall]

The zinc will burn off in a cylinder.  The melting point is approx. 410 F.  It becomes white and brittle and will then flake off.  Zinc-nickel would be ideal but, the process uses cyanide bath and is dangerous and difficult because of the narrow heat range as applied.  (I've some experience in metallurgy and plating from my trade)

[pd]

The zinc will burn off in a cylinder.  The melting point is approx. 410 F.  It becomes white and brittle and will then flake off.

So , maybe filling the cylinder with a balloon might be a good idea ?

Pete .

[carryall]

Oddly enough, some common products will help.  Liquid nails is what we filled tapped holes with before dipping into a commercial galvanizing tank to prevent it from entering.

[Ricks]

If Zinc burns off at 410, that should hold up on a Simplex cylinder, as they usually don't get that hot.

[pd]

The zinc will burn off in a cylinder.  The melting point is approx. 410 F.  It becomes white and brittle and will then flake off.

So , maybe filling the cylinder with a balloon might be a good idea ?

Pete .

Thinking a bit more , any zinc in the upper cylinder , think combustion chamber , would simply burn away and out the exhaust .
Any zinc on the lower part of the cylinder would/should never reach 400° and thereby stay attached ( until it wore off ) and act as a lubricant , like it did back in the day .
That seems to make sense .

Pete .

[Eitek1]

 I guess you could just paint the surfaces you didn't want to plate. Once you are done plating you can just hit those surfaces with paint stripper. Paint stripper shouldn't touch the plating.

For a cylinder a plumbers plug in the bottom and a couple of corks should do it. I can't imagine there is enough hydrostatic head to make the water breach those seals.

[pd]

I wonder if tape would stay in place long enough to protect a surface .

Pete .

[carryall]

Don't think you'd want the residue and pieces of zinc messing with the cylinder walls and possibly scoring them for ring seating.  It's not as soft as lead contained in the "old type"gasoline.

[pd]

You might have a point , Paul .
Maybe best on the cautious side .

Pete .

[Ricks]

You might have a point , Paul .
Maybe best on the cautious side .

Pete .

Pete, quick worrying about this bs, and get that thing running! Lol

[pd]

Ha . No worries here , Rick .

Just considering options while I have the jug off to replace the base gasket .

Pete .

[pd]

This morning , I wrapped my piston with waxed paper and inserted it into the cylinder . A couple of thicknesses of waxed paper makes for a real tight fit .

Then I applied a couple of decent sized 'dabs' of JB Weld to the lower portions of the exhaust ports . I'd prepped the ports for this yesterday by cleaning and scoring any surface that would have JB Weld applied .

After letting the JB set up to a state not fully cured , I worked it down to were the ports would be totally closed when the piston is dead stopped at the top of the cylinder . That will insure enough skirt coverage for a decent seal of the ports at the top of a normal stroke , by at least .030" .
I'd trued the base gasket surfaces previously , so the extra coverage by the JB should be adequate .

I'll leave the JB alone for a day to get a full cure before a light hone and re-assembly of the motor .

Pete .

Here's a follow up to the above experiment :

While I had the cylinder off to replace a base gasket , I checked the exhaust ports for the condition of the JB Weld I'd 'installed' .
The majority of the JB Weld has been blown out . What was left seemed less than brittle , but there wasn't enough left to do much , if any , good . I simply smoothed the leftovers and reset the cylinder .
To be honest , I'm not sure the original buildup did any good . Hard to tell just how long the JB Weld stayed where it was put .

The motor acts much the same as before . That being it starts using the drill but not the kicker .

Pete .

[pd]

Ha . You guys are way too nice .

Not a single 'I told ya so' .

I'da done it anyway . Just to prove to myself , by my own means .

Pete .

[Ricks]

Ha . You guys are way too nice .

Not a single 'I told ya so' .

I'da done it anyway . Just to prove to myself , by my own means .

Pete .

Pete, no reason to beat a dead horse!  LOL

I wonder if the flywheel is the issue. I know you reattached a magnet or two.

[pd]

Ha . You guys are way too nice .

Not a single 'I told ya so' .

I'da done it anyway . Just to prove to myself , by my own means .

Pete .

Pete, no reason to beat a dead horse!  LOL

I wonder if the flywheel is the issue. I know you reattached a magnet or two.

Rick ,

I did re-glue a magnet ( the same one ) , twice . Both times the original location was very evident and easy to place the magnet . I don't think that's an issue , as the spark is fairly strong and consistent .

The strength of the magnets as a whole might be suspicious . I now that sparks can act differently in open air than under compression . But , once the motor starts , it runs pretty smooth and only dies when I play with the carb settings .
On another bike forum , there's a saying that gets repeated occasionally : " 90% of carb problems are electrical" .

It would be nice to be able to tell if that^ is the case , here .

And , as for dead horses , I think this one is verified dead . LOL

Pete .