1975 Commando 850 restoration

Larry S

Larry S

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One week ago I brought home my 1975 850 Commando Roadster. I got this bike for free, well almost free. All I had to do was repair a garage door and the bike and clean title were mine. A couple of other caveats were that I wouldn’t part the bike out or sell the bike and that I would restore it to the best of my ability. The widow and former owner also gets first ride when I get it on the road. Wish me luck on my project.

When I brought the bike home the engine was seized so I pulled the plugs and poured diesel fuel into the cylinders. While that was working it’s magic I removed the seat, tank, side covers, oil tank, carb, fenders, turn signals, tail light assembly and headlight assembly. After doing that I turned my attention to the seized engine. I put the transmission into fourth gear and rocked the rear wheel back and forth, over and over until I thought I felt a slight movement. Finally I got it free! What a great feeling that was! I drained the engine oil and it looked and felt brand new.

This bike has been sitting since 1980 or so with fuel in the tank and the tank is full of gunk and rust. Getting this clean is my weekend project. Tips?
 
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$pend a fortune seeing as you got it almost for free. Grease everything and of course the layshaft bearing change up.
 
Welcome!

Inspect the bores, as they are likely in need of a hone since the rings stuck to them so badly.

Check out the rebuilds section of the forum, and read up.
 
Larry S said:
One week ago I brought home my 1975 850 Commando Interstate.
This bike has been sitting since 1980 or so with fuel in the tank and the tank is full of gunk and rust. Getting this clean is my weekend project. Tips?
Click to expand...

Hi Larry

I use washing soda and electrolysis method its simple and effective on rust and gunk link to video below. Good luck with your project.

 
I've done three tanks this way. It is slow but it works. But the old dodge of using a battery charger as a power source is getting harder because modern ones don't seem to work and the old ones burn out it after a few days.

And in general, take copious amounts of pix from all angles before you get too far. Most useful at reassembly time.
 
Agree with Onda take hundreds of pictures before you take it apart from all angles. I did and it has paid dividends. I stripped an 850 Interstate which seemed pretty much standard.
Good luck
 
Onder said:
I've done three tanks this way. It is slow but it works. But the old dodge of using a battery charger as a power source is getting harder because modern ones don't seem to work and the old ones burn out it after a few days.

And in general, take copious amounts of pix from all angles before you get too far. Most useful at reassembly time.
Click to expand...

Hi
Regarding the power supply : A computer power supply works really well black and yellow cables on a HDD plug my t160 tank below power from a pc power supply.

1975 Commando 850 restoration
 
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I had great success removing the rust from a tank with Evap-o-rust product. Clean as a pin without taking any metal off.
Jaydee
 
I’ll be the guy that gets rotton tomatoes thrown.
Those romantic old stories (yes! You proved them true) of using penetrating weasel piss to free up stuck old engines.....
Well, maybe a vintage make & break or something, but....
The rust that held it is still in there.
It MAY start, MAY run....
But the iron oxide, which is harder than everything in there, WILL destroy parts. Quite costly parts.
I recommend (if you have the skillset) removing the head & cylinder to inspect. If you find no problem, you’ve lost $50 worth of gaskets.
It may save you thousands.
 
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grandpaul said:
This thread needs to go in the Projects section, with LOTS OF PHOTOS!
Click to expand...
As soon as I figure out how to post pics, I’ll do so. I’m a newbie at this computer stuff so bear with me. I’m still figuring out this great website. I’ve been reading threads on here for a couple months now but have never posted. I’d put this thread in Projects section if I knew how. Moderator?
 
concours said:
I’ll be the guy that gets rotton tomatoes thrown.
Those romantic old stories (yes! You proved them true) of using penetrating weasel piss to free up stuck old engines.....
Well, maybe a vintage make & break or something, but....
The rust that held it is still in there.
It MAY start, MAY run....
But the iron oxide oxide, which is harder than everything in there, WILL destroy parts. Quite costly parts.
I recommend (if you have the skillset) removing the head & cylinder to inspect. If you find no problem, you’ve lost $50 worth of gaskets.
It may save you thousands.
Click to expand...
No rotten tomatoes for you! As soon as I get something to eat I’m going to do just that, pull the head and cylinder for inspection.
 
So where the h_ll was I when they were handing out free Commandos ? LOL - good for you . Best of luck and let’s see pics .
You will need to be VIP member to post pics directly or else you need a photo hosting site . I use Imageshack .
 
Be sure to run some inline filters for a period after the electrolysis is over because the silt doesn't all rinse out easily. At least it didn't for me, although it's almost down to nothing now after 1 1/2 years which I'm good with.
 

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