Alpha Dog Builds a CX500

AlphaDogChoppers

Science is true whether you believe in it or not.
It occurred to me the other day that I have been on the forum for about a year and a half, and never posted a build thread. Fact is, I don't do a "build" all the often. I work on other people's bikes, and sometimes it's just mundane shit like repairs.

This is different. This is a bike that came into my shop as a non-runner, although it was in pretty decent shape overall. Always kept inside, so it was not all rusty and corroded. It was that awful Honda shit brown color, though, and had minor dents and other cosmetic flaws.

My first task was just to get it running. The fixed pulsars of the stator assembly were toast, so I dropped the engine, split the case, and changed it out.

CX500-Engine-01.jpg


Inside, everything was pretty clean.

CX500-Engine-02.jpg


It also had clogged up carburetors, and was getting no fuel at all. Routine carb clean. I also changed the jets, installing a 120 intermediate main jet and a 90 main jet. I removed the restrictive flame arrester in the airbox and the rubber intake snorkel. Also installed a K&N filter.

So, I got the bike running. Still seemed a little lean but too early to tell. The owner of the bike suspected low compression, and a compression test confirmed that. Next was an engine tear down.
 
Its about friggen time you did something. Well besides always "saving the day" and/or "scolding the lazy".

I really like the appearance of those engines.
 
Re-ring on the CX500 requires tearing the engine down pretty far. The cylinders are part of the cases, so you have to go into the bottom end and pull the connecting rod big end caps to pull out the pistons. Cylinders were in excellent condition, still showing cross-hatching. Rings also measures well within tolerance for end gap, between 12 thou, and 17 thou. Still, I found a set of NOS standard rings on eBay for $40, so I changed the rings anyway. I would have been perfectly comfortable with re-using those rings if I needed to.

So, given how far I had to tear it down anyway, I striped the cases down completely and sandblasted them for powdercoating. Masking of the areas where I wanted no powdercoat was a fairly extensive jobs.

CX500-Engine-03.jpg


The low compression was due to poorly adjusted valves causing a little leakage even after adjusting them. Damage was minimal, and I was able to make them liquid tight with just a little lapping with valve grinding compound. Here is a shot of one of the heads after assembly with the powdercoat and re-polished valve adjustment cover.

CX500-Engine-04.jpg
 
This silver vein finish is really nice. It's got silver and black in it, but the two colors don't mix. It makes a textured two-color finish. I then coat it with clear powdercoat to make it smoother and easier to clean.

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For the clutch cover, I filled the Honda badge and groove with silver vein, then did clear over the whole thing.

CX500-Engine-11.jpg


I did a little color accent on the valve adjustment covers with some candy red powder laid into the grooves before doing the whole thing with clear powder.

CX500-Engine-13.jpg
 
I did a lot of details along the way. Things like the radiator, which had been rattlecan painted as had the radiator enclosure. I striped it all. The radiator was all copper and brass. pretty after I stripped it. I gave it a coat of clear lacquer to slow down oxidation. the enclosure was aluminum and chrome. That got all polished, and the aluminum was clear powdercoated.

It had an ugly plastic grill in front of it. I painted it with a silver metallic paint, using plastic primer first, of course.

cx5003.jpg


The tank badges got some special treatment. First was a coat of candy red powdercoat. Then I masked off the letters with high temp tape. That involved about 4 hours of meticulous work with an Exacto knife. Then it got silver vein powdercoat to do the background. Then I stripped off the masking and covered the whole thing with powder clear.

cx500-badge.jpg


Paint was next. The owner just said red and black. I used the lines of the bike to tell me how to mask it out. At first I didn't even like it, but after the clear, it looked a lot better. I set off the black and red with silver pinstripe.

cx5004.jpg


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Very nice!

AD, with the two tone powder coast in place, were you tempted to go with a more speckled approach through the other painted surfaces (tank, fenders,...) rather than the traditional mirror paint finish?

D.
 
damiansd said:
AD, with the two tone powder coast in place, were you tempted to go with a more speckled approach through the other painted surfaces (tank, fenders,...) rather than the traditional mirror paint finish?

No. Never considered anything but red and black, as this is what the owner wanted. He had no idea in the beginning that we were going to powdercoat the engine.

He just picked up a dual piston front caliper and mounting bracket to upgrade front brake performance. I am powdercoating it to match the engine. Front forks are getting the legs polished and clear powdercoat, too. A few more things to do. I'm in the process of talking the owner into doing CXMAN's Mikuni carburetor kit.
 
Fantastic work on that motor. Is the body color more red than the pictures indicate? It looks very orange.

Love that silver vein. That and hammertone silver are my favorite for "utility" type parts that are seen but not meant to be seen.

DSC00105.jpg


-Deek
 
Yeah, it's a much richer red than it appears in the photos. The sun was very bright, and my good DSLR camera was stolen from my desk recently, so the quality of the photos is a bit sub par.
 
As it turns out, CXMAN's Mikuni kit requires that we remove the airbox and side covers. We don't want to go that route, so I will continue tweaking the stock carbs.
 
He has one that you can retain the side covers........the intakes come into the centre a little more and allow the side covers to stay on, but the airbox has to go
I have a set on my cx custom and man does it get up and go! huge difference from stock (first time out, unintentional wheelie)
 
Very nice, Alpha.

I am looking at getting a CX650 right now, haven't decided but after seeing your work I am getting closer to getting it.
 
Kamn said:
He has one that you can retain the side covers........the intakes come into the centre a little more and allow the side covers to stay on, but the airbox has to go
I have a set on my cx custom and man does it get up and go! huge difference from stock (first time out, unintentional wheelie)

We ended up going with the Murray carb kit, and the performance is simply astonishing!

I was able to keep the air box. I simply carved it up a bit with a reciprocating saw to make room for the pods to stick into it. That way, I still had the hanger posts for the side covers, and the oil breather still had a place to go. I also polished up the Murray intake manifolds to pretty them up. They are beautifully made with nice welds. A little sanding and polishing and they look awesome!

Anyone building a CX500 would be simply out of their mind to not do the Murray carb conversion. It starts pulling like mad at 2,500 RPM, and keeps pulling well past redline. The owner of this bike had it up to 110 mph and it was still gaining when he closed it down. The speedometer was pegged at 85. It was the GPS that documented the speed at 110. Tony was certain it would go to at least 115 if he had kept on it.
 
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