Magnusen's GS1000 rebuild

[smagnusen]

I’ve recently started rebuilding a ‘79 GS1000 and instead of creating my usual isolated posts, I thought I’d start an ongoing thread for the project. I’m laying it all out to share my successes and failures – hopefully sharing something useful for others along the way.

Here's a picture of the bike as received

Carbs

The first thing I did was pull the carbs for a good and proper rebuild. I didn’t take pictures at each stage so here’s a quick recap on the process.

Pulled
Pictures taken for reassembly

(apology in advance - all pics will be crappy phone pics)

Carbs disassembled and pieces placed into egg cartons
Broken parts fixed or replaced
http://www.thegsresources.com/_forum/showthread.php?t=140834
Each carb dipped in Berrymans for 24hrs.
Pic is post berrymans, pre soda-blast

Carb bodies soda blasted and boiled to remove residue
Carb bodies soaked in iron phosphate to promote adhesion, rinsed, heated to 425 for one hour to expel gasses, wiped with acetone, hit with propane torch to kill any leftover lint, then taped and preheated to 250F and ready for powder coating (sounds worse than it is)

Carb Bodies Powder Coated with Caswell’s Black Cat Satin and baked at 400F for 15 minutes

Tops and bowls polished with sandpaper, dremel and home-made bench-top buffer up to white rouge.

 

[smagnusen]

Finished Carbs

Having never heard the bike run, I was happy when I threw these on and she fired up instantly.

More on the way---

 

[Guest]

Hope the inside looks as good as the outside.
Excellent job!

 

[posplayr]

Looks great; I need to try the powder coater that I bought (Harbor Freight). What kinda oven did you get?

 

[smagnusen]

I did the h.f. gun as you can sorta see in the pic, but promptly did the recommended mods before even turning it on. I'll get a pic up. I do have a nice space cleared out in my garage for a refrigerator-turned-powder-coat oven, but haven't tackled that yet. All the parts were small enough that I just used a toaster oven. Worked great.

 

[posplayr]

but promptly did the recommended mods before even turning it on.

I guess I have been out of the loop and am definitely not PC literate; what are the recomods?

 

[smagnusen]

The H.F. gun mods are simple and seem to be recommended by many. The main idea is to move the powder hopper off the top of the gun to a seperate location. From what I've gathered, this improves the cloud and helps prevent spitting. What you want to do is run tubing to and from the gun to a seperate powder container - I used mason jars because of the storage convenience, tight seals, and availabilty. I'll get some pics to show you - the whole mod takes an hour. They also recommend you open the gun's airflow to the maximum position, and feather some of the molding from the gun's nozzle area and tips. In my case, I found it best to remove the tip altogther to get the powder directed forcefully enough to get into the tight spots. Here's a link where LeeGS550e gives some helpful info and sage powder advice
http://www.thegsresources.com/_forum/showthread.php?t=141177

Also, www.caswellplating.com has a decent forum and you can search for more mod info.

 

[tkent02]

Very nice, I even have a toaster oven.
Have not done this as I was thinking I needed a big kitchen oven in the garage.

Off to H.F.!!!

 

[smagnusen]

If you're going to do these, one tool I found really handy was an old set of punches. You'll notice on the hanging carb all the circular pieces of tape to cover the various holes. These were a snap with the punches. I simply put a piece of the high-temp tape [from caswell] down on a rubber sheet, cut the sizes I needed, and then peeled them off with my fingers or an exacto knife. I also remade all new gaskets in an hour with the help of these.

 

[Go Mifune]

Nice Work!
Let me know when I can stop by and drop mine off:-\\\

 

[smagnusen]

So I just got my air filters from APE and was surprised to find that they are not oval but round-shaped. I know people prefer the oval shape because of the increased surface area and better flow, and generally stay away from the round shape.

These look nice, but the reason I spent $70 with APE was to stay away from the cheapo emgo-style filters.

These are going on the above VM26s. I was thinking of trying to return these and get the oval shaped ones - what should I do? Maybe the 26's don't need as much air?

 

[TheCafeKid]

I dont know for a fact, but I would bet that the APE product is still flowing MUCH better than the EMGO junk. The problem with the EMGOs actually lie in the screen material they use. On the 26's I dont think the round ones are a problem, I have used them with decent enough success, and frankly i think they look the part moreso than the ovals. APE doesnt sell junk, so I would personally stick with those.

 

[Jethro]

So I just got my air filters from APE and was surprised to find that they are not oval but round-shaped. I know people prefer the oval shape because of the increased surface area and better flow, and generally stay away from the round shape.

These look nice, but the reason I spent $70 with APE was to stay away from the cheapo emgo-style filters.

These are going on the above VM26s. I was thinking of trying to return these and get the oval shaped ones - what should I do? Maybe the 26's don't need as much air?

Those are the exact filters that were on my 83 when I bought it, only mine were by K&N. They worked just fine on the CV carbs anyway.

 

[smagnusen]

Okay thanks guys that's enough for me to give the pods a go. For anyone interested, here's some pics on my take of the HF powder gun mod:

The hopper that used to sit atop the gun is now a mason jar connected via vinyl tubing. I cut off the end of the pipe that's used to circulate the powder and transplated it to the jar. The connectors are simply air tool couplers, which, as it turns out, conveniently fit the tubing.

Not much to it - one tube pushes air into the jar and vluidizes it powder and the second takes the air powder mixture back to the gun. This frees up the gun to be held at any angle and makes for a more consistant and better shaped cloud.

 

[Dreef1999]

Could we get a couple other angles on those pods? Particularly the interior and etc.

 

[smagnusen]

Sure, here's a few-

They're a little dusty from sitting around now for a week - looking forward to getting them out in the wind soon

 

[smagnusen]

Step 2 is painting. The frame is in fair shape, so I'm planning on doing the tank, fender, seat moulding, tail piece, fairing, and even though I'm not putting them on, the side panels.

Having never done any of this before, I didn't really want to deal with my decrepid tank. I bought one from Ebay that was supposed to be in better shape. It wasn't. Actually, it wasn't even the right tank.

After a hard look at the dents, rust, and shoddy lead and braze repairs coving my tank, I set in.

I first ground out the spot-welds on the bands that hold the badges. (I'm filling those in) This was easier said than done. I first found that I wasn't grinding the correct area. There were three welds on each band. I ground too deeply on the first one and made my way into the tank. I had much better luck on the remaining 5 welds by switching my approach. The key was to grind down through the weld closely to the bottom of the band, but not all the way to where the metals meet, then bend and twist the metal band with a pliers until it pops cleanly from the tank. They're not fun to get off but I'm glad I did because the area was filled with rust.

Sanding revealed the tank was practically covered in body filler. This pic shows the top coat on the left moving into primer and then the tan body filler.

I actually took a belt sander to it and got about 90% of it off before hitting it with aircraft stripper.

I got most of the remains off in a big mess with steel brushes. The bottom was covered in a film of creaping rust, and there were a few holes that revealed themselves.

To get rid of the remaining crud and rust I hit it with my HF sand-blaster. I have a larger sand-blaster, but honestly the H.F. hobby blaster works remarkably well. I used it to soda blast my carb bodies as well. Here's the tank getting blasted-

 

[smagnusen]

This is the nice clean bottom after a quarter bag of sand

Here are a couple of the holes

And here they are mig welded [as you can see, I'm a professional welder. uhm, no.]

 

[smagnusen]

Having never done any of this I expected to fully suck at it. It would have been nice to get some hands-on guidance from someone who knows what they're doing, but at least I was free to completely screw-up away from anyone who knows what they're doing.

There was a reason why the tank was covered in body filler. It needed it. After throwing a bit of filler on here and there, it was clear I wasn't going to get any smooth clean lines.

To cheat, I dug out this tool I bought from a garage sale years ago not knowing what is was or what i would ever use it for.

It's called a calibrated adjustable curve. It bends gracefully and holds it's shape, it also strangely smells absolutely aweful - no joke, like a rotting possum - best not to smell it. Anyways it turned out to be a great tool for finding the highs and lows, along any sweeping curve.

The other tool I used was home-made. To keep the natural curves of the tank while sanding I made my own sanding block. Why? Mostly because I was too ignorant to know much better ones existed or where to get one. That said, I loved this tool. Fashioned from a 3 x 24 inch piece of plexiglass, backed with thick hardware-store felt, and covered with a cut-open length of sanding belt, this had a good balance of flexibility vs. rididity to quickly follow and sand the curves of the tank.

Here's the tank ready for primer. Looks ugly I know, but if I close my eyes and run my hand across it, I cannot make out a single imperfection.

 

[smagnusen]

And here's a couple pics of the other pieces-

I ground and sanded down the lens area on the tail piece because I'm filling it in. I'll mount some reflectors below the tail but I don't want those areas in the way of the paint scheme. I'm going to fill behind the lens area and reinforce the whole piece (becuase it's inherently flimsy) with fiberglass.

The fairing, by the way, is from 'The Dude' Some of you know him. It's the first from a new mould and it is
very
well
done.

Can't wait to screw it up.