GPR Camp: Replica Racers

I know it’s hard to fathom, but I’m like $135K per year below the poverty level here in San Francisco. I don’t even have a garage. I’m very fortunate to have a kitchen in which to do some of this stuff, but most of my wrenching is done out in the street. That’s why when it rains, unlike other folks, I can’t wrench.

So I have to achieve all of this with very basic technology. Yeah it’s very difficult, and takes way more energy, but that’s I can do.

Yes I could go to Harbor Freight, and pick up a “portable” sand blaster, an air compresser, etc., but I still wouldn’t have a place to use that stuff. Imagine what the neighbors would think if I was out in the street sand blasting! And don’t think I haven’t thought about it!!

I’m getting ever closer, but I’m also out of time. Tomorrow is the last dry day so I have to paint tomorrow. It’s not going to be perfect, but hopefully it will be a lot better than it was, or would have been had I not put in all this effort.

Berkeley wrote: ↑

Mon May 13, 2019 9:06 pm

Ok cool...good to know.

How about laser removal?

This seems to remove all unwanted surface finishes.. quite expensive but there must be companies renting this out?

Anyway just an idea.

Very interesting technology. Maybe a bit pricey at this point...

They were talking about rust removal, I wonder what it does with heavy oxidation on aluminum.

Even when you have the paint and corrosion removed you also need to apply a new coating of some kind to prevent corrosion.

If you have the part off and completely disassembled you are able to coat it with something better than just spray paint.

Okay so yeah just spray paint, and yeah it’s not awesome, but it’s all I can do—sure looks awesome in red though.


Preparation takes a long time with painting something. This was the last stage, and it didn’t go as planed, but it went well enough. I used the bike stand to support the engine while I painted it, and a wire coat hanger to hook it on the stand. It’s nice to work with an engine that is light enough to do these sorts of things.






These shots are out of order thanks to the order mangling that imagur inflicts, but here are a bunch of photos of the progress during the painting.

The moment the paint started hitting the engine I instantly saw the areas that I had missed with the removal of the stock paint. This was a bit of a rush job so I expected this to happen, but I really didn’t expect to me so smacked in the face by it!


I did a little clean up work, and messed up the paint a bit in some places. It needs a full 24 hours to cure so I can’t start assembling it until later tomorrow. But it’s fine I still need a few parts before I can do the fun assembly anyway, and if I remember correctly the 075 engine is harder to fit into the Second edition chassis, so I might have to assemble it in the bike.

I have one EBE075 with a good top end, and one with a good bottom end, or so I thought. Here’s the top end I’ll be using with this bike.




There’s some scoring, but I should be able to clean it up a bit.

It takes a horrendous amount of time to clean up these things.


Slowly things get cleaner and cleaner.


I noticed that some work had been done to this exhaust port. The image on the left is a stock 075, and the one on the right has been cleaned up and smoothed out.


The scoring on the cylinder is fairly clear in these photos, but it’s not too bad.

Picked up a wrist pin and bearing from Treats. The stock pin measured at 37.6mm. The closest they had at Treats was a 37. The bearing measured 12x15x15.7, and the closes they had was a 12x15x15. This is the deepest scratch on the piston. Hopefully it wont cause too much trouble. If I could replace it and the rings I would do so. Notice that the crown is concave.


A muriatic acid bath clean the head nut up nicely


Cleaning up the head required much hand work.

Have you ever considered a small blast cabinet for clean-up work?

Soda or plastic media will clean but not remove material on critical aluminum parts like carbs, heads, cylinder ports, pistons, etc.

It wouldn't need to be very large, and you wouldn't need a large compressor to run it.

Just a thought, though I know your workspace is limited.

I have looked into it, but I really don’t have a place for it.

The vinegar experiment went well enough. It takes a lot longer, and comes out nearly as well. It is of course much safer than muriatic acid, but since there are many fewer free hydrogens the process requires more time to be effective.