My MKIII rebuild

PhiloMcGiffin · Apr 23, 2010

Coco... Great job! Keep up the good work. The CNW guys are the best!

I'm ready to start the re-assembly of my "Barn Find" Which can be seen here: classic-barn-find-norton-commando-t5658.html

So your rebuild has been an inspiration to me... I know you're busy but some recent progress pictures would be greatly appreciated and very helpful. My frame comes back next week, so I'll be posting my progress as well.

Coco · Apr 26, 2010

Old tank and new SS exhaust is on. The alloy Wilcox tank I bought is having a fitment problem and I need to get it notched out to accomodate the oil tank mount which I assume he forgot about. I'm going to get some local guys to notch and reweld for me. I fit the tank when I got it, and everything was fine but I never had the oil tank mounted then, so I didn't notice the misalignment. Custom pieces are a pain in the ass.

I'm sitting on the bike making some "vroom vroom" noises.

Hortons Norton · Apr 26, 2010

Looking really close now Coco, Just in time for the riding season. Keep up the great work and thanks for the pictures.

Coco · Apr 26, 2010

Hortons Norton said:
Looking really close now Coco, Just in time for the riding season. Keep up the great work and thanks for the pictures.

It is really close. Now I've found I lost that little "C" clip that you need to screw the head light trim ring to the shell.

It's always something.

grandpaul · Apr 26, 2010

I really like the point where I get to stop making the "vroom vroom" sounds, and let the BIKE start making them!

swooshdave · Apr 26, 2010

I's looking great. Couple questions.

1. What tires did you go with?
2. Can you show how a better picture of how you mounted the "podtronic" unit?

Hortons Norton · Apr 26, 2010

Look like Bridgestone Battlax to me.

swooshdave · Apr 26, 2010

Coco said:
Old tank and new SS exhaust is on. The alloy Wilcox tank I bought is having a fitment problem and I need to get it notched out to accomodate the oil tank mount which I assume he forgot about. I'm going to get some local guys to notch and reweld for me. I fit the tank when I got it, and everything was fine but I never had the oil tank mounted then, so I didn't notice the misalignment. Custom pieces are a pain in the ass.

Do you have better pictures of the issue with the tank?

Coco · Apr 27, 2010

swooshdave said:
Coco said:

Old tank and new SS exhaust is on. The alloy Wilcox tank I bought is having a fitment problem and I need to get it notched out to accomodate the oil tank mount which I assume he forgot about. I'm going to get some local guys to notch and reweld for me. I fit the tank when I got it, and everything was fine but I never had the oil tank mounted then, so I didn't notice the misalignment. Custom pieces are a pain in the ass.

Click to expand...

Do you have better pictures of the issue with the tank?

No pics, but I'll explain. The roadster tank I had made is a few inches longer than normal and slightly larger overall to hold more gas. There is a cut out underneath the tank in and around where the oil tank rubber mounts are secured to that first cross member of the frame. I think he just goofed on the measurement as I need about an extra inch or so notched out. No biggie. A local fab shop can remedy it for about $100 which is what it would cost me to get the tank down and back from Mr Wilcox anyway and I only have to wait a week to get it done up here.

When you say podtronics you are referring to the Sparx regulator I have mounted behind the battery tray? If so yes, I can post another picture for you later if you wish.

Coco · Apr 27, 2010

Dave, tires are bridgestone Battlaxe. For some reason I want an Avon speedmaster up front now but that would only be for aesthetics and not performance.

swooshdave · Apr 27, 2010

Coco said:
swooshdave said:

No pics, but I'll explain. The roadster tank I had made is a few inches longer than normal and slightly larger overall to hold more gas. There is a cut out underneath the tank in and around where the oil tank rubber mounts are secured to that first cross member of the frame. I think he just goofed on the measurement as I need about an extra inch or so notched out. No biggie. A local fab shop can remedy it for about $100 which is what it would cost me to get the tank down and back from Mr Wilcox anyway and I only have to wait a week to get it done up here.

When you say podtronics you are referring to the Sparx regulator I have mounted behind the battery tray? If so yes, I can post another picture for you later if you wish.

Click to expand...

Yes, regulator (I believe the Podtronics and Sparx do the same thing).

If the tank is longer, will you use an Interstate tank or modify a Roadster one or?

Coco · Apr 27, 2010

swooshdave said:
Coco said:

swooshdave said:

No pics, but I'll explain. The roadster tank I had made is a few inches longer than normal and slightly larger overall to hold more gas. There is a cut out underneath the tank in and around where the oil tank rubber mounts are secured to that first cross member of the frame. I think he just goofed on the measurement as I need about an extra inch or so notched out. No biggie. A local fab shop can remedy it for about $100 which is what it would cost me to get the tank down and back from Mr Wilcox anyway and I only have to wait a week to get it done up here.

When you say podtronics you are referring to the Sparx regulator I have mounted behind the battery tray? If so yes, I can post another picture for you later if you wish.

Click to expand...

Click to expand...

Yes, regulator (I believe the Podtronics and Sparx do the same thing).

If the tank is longer, will you use an Interstate tank or modify a Roadster one or?

I'm using the longer Wilcox tank but will modify it to fit over the oil tank mounts. I'm tired of chasing my own tail with this build and want it over with asap so I'm dealing with the Wilcox seat and tank and leaving the bike that way. I want to put more energy into my Triumph chop instead of going in circles with this Commando so I can just ride the thing already, because to be honest, I'm sick of dealing with this kind of crap. The Triumph is made of bits and custom pieces and I have had less trouble mating a 1973, 750 motor into a 1970, 650 frame, using a 1996 Harley Sportster front end. Those pieces went together more smoothly and with less effort than my Commando using stock parts.

rmaten4 · Apr 28, 2010

Hello Coco,

I stumbled across your MKIII rebuild a year after you posted this article.

I too have an MKIII that was totally rebuild. Every nut, bolt, and bushing has passed through my hands. I have numerous modifications with finned valve covers being just one of them. I bought mine about 25 years ago, but they are similar in shape to yours. Not only do I think they make the engine look much better, but thay have a functional side as well. I live in the bay area, California were the temperature is always going over 90 degrees F in the summer. Most of the USA cooks in the summer time, and I can tell you with absolute certainty you will notice the Improvement in cooling from the stock covers.

You mentioned what a mess your wiring was. I tore all my wiring out and started over. Ended up with Sparks 3 phase alternator (does not fit without some modification). Podtronics 3 phase voltage regulator/rectifier. Pazon electronic Ignition firing a single (lost spark system) Dyna coil. Chrome Plated electric starter from Harley Sportster plus Harley starter solenoid. All components wired together with stock (but rebuilt) MKIII Norton handlebar switches. System uses a negative ground like your car. In fact my bike starts like a car. A brief push of the starter and it always comes to life. I have had many carburetor adventures. First a single 34mm Mikuni. Then sunk about $300 into re-sleeving and re-building my original Amals. Then went to dual 32mm Mikunis ,but air filters just don't fit well. Now running a 36mm Mikuni single with MAP manifold.

Got any pictures of your finished bike?

-Rick

Coco · Apr 30, 2010

rmaten4 said:
Hello Coco,

I stumbled across your MKIII rebuild a year after you posted this article.

I too have an MKIII that was totally rebuild. Every nut, bolt, and bushing has passed through my hands. I have numerous modifications with finned valve covers being just one of them. I bought mine about 25 years ago, but they are similar in shape to yours. Not only do I think they make the engine look much better, but thay have a functional side as well. I live in the bay area, California were the temperature is always going over 90 degrees F in the summer. Most of the USA cooks in the summer time, and I can tell you with absolute certainty you will notice the Improvement in cooling from the stock covers.

You mentioned what a mess your wiring was. I tore all my wiring out and started over. Ended up with Sparks 3 phase alternator (does not fit without some modification). Podtronics 3 phase voltage regulator/rectifier. Pazon electronic Ignition firing a single (lost spark system) Dyna coil. Chrome Plated electric starter from Harley Sportster plus Harley starter solenoid. All components wired together with stock (but rebuilt) MKIII Norton handlebar switches. System uses a negative ground like your car. In fact my bike starts like a car. A brief push of the starter and it always comes to life. I have had many carburetor adventures. First a single 34mm Mikuni. Then sunk about $300 into re-sleeving and re-building my original Amals. Then went to dual 32mm Mikunis ,but air filters just don't fit well. Now running a 36mm Mikuni single with MAP manifold.

Got any pictures of your finished bike?

-Rick

Hi Rick. Bike is not quite done. Just a few glitches I ran into last minute but it should be on the road in a few weeks. I have to wait for a gas tank that needs a slight mod and do a motor break in and shakedown then it is ready for the road.

I also used a Sparx 3-phase system but mine went in without a hitch and no mods or fiddling needed. I went from a 36mm down to a 34mm Mikuni. Reasoning is that 36 is a bit big and I could not find an air filter to work as I am using a battery tray out of a MKII. Did you have to modify your MAP manifold? Mine was horrible. I had to reface both mating surfaces and clean off the casting swarf on the outter edges. You could slice your finger open, it was so sharp. The finish was also a weird dark grey so I sprayed it with some Wurth aluminum paint and now it matches the head.

rmaten4 · Apr 30, 2010

Be Careful about modifying your intake manifold.

I modified the first manifold I bought which was a Sudco (not current MAP I have now) .
Like you, I though the intakes could use a little "cleaning up". Maybe I overdid it, because somehow I threw off the balance of things resulting in my left cylinder running richer than my right. You might reason that even with a two into one manifold a little less than perfectly balanced, one cylinder might draw in a little more fuel/air mixture than the other, but would NOT change the actual ratio of fuel to air between cylinders. Apparently my messing around did just that. The condition drove me nuts trying to dial in my carburetor. I finally tried a new MAP manifold, and bolted it on with molesting the intake ports in any way. Now when I do a throttle chop and read the plugs they look the same.

We have all heard it said that if you are going to mess around with intake ports, or intake manifolds, you really need to have a flow bench. After my experiences, I think there is a lot of truth to that.

Coco · Jun 21, 2010

rmaten4 said:
Be Careful about modifying your intake manifold.

I modified the first manifold I bought which was a Sudco (not current MAP I have now) .
Like you, I though the intakes could use a little "cleaning up". Maybe I overdid it, because somehow I threw off the balance of things resulting in my left cylinder running richer than my right. You might reason that even with a two into one manifold a little less than perfectly balanced, one cylinder might draw in a little more fuel/air mixture than the other, but would NOT change the actual ratio of fuel to air between cylinders. Apparently my messing around did just that. The condition drove me nuts trying to dial in my carburetor. I finally tried a new MAP manifold, and bolted it on with molesting the intake ports in any way. Now when I do a throttle chop and read the plugs they look the same.

We have all heard it said that if you are going to mess around with intake ports, or intake manifolds, you really need to have a flow bench. After my experiences, I think there is a lot of truth to that.

I just took the razor sharp edge off the outter edges of the casting. I didn't go mental making the ports larger ect. I had to level the manifold as well since it was far from being flat. I just did some basic clean up on the manifold that should have been done by the manufacturer.

Coco · Jun 21, 2010

Well, this build is done except for a seat bracket I have to make. I do first engine break in tonight, and mess with getting the headlight trim ring on.

I'll make a seat bracket out of some flat stock over the next couple of days, bolt it between the shock bolts and I'm ready for the second phase of break in.

After that, if everything goes smoothly (nothing has gone smoothly with this build) I can register and insure it.

No pics since some drunken dumb ass knocked the camera out of my girlfriend's hands while she was in Vegas last month with her freinds. So she says anyway :roll: . I'll post pics and maybe some video when we get a new camera soon. We're getting a Nikon D5000 which a sweet little camera.

Coco · Aug 9, 2011

Update since finishing this bike last fall. I now have good photos and the Old Britts tail light that I waited a couple of years for showed up early this spring. My giirlfriend finally forced me to let her snap some proper photos so here are a few for any who are interested. For some reason these photos are appearing a bit cropped.