Author Topic: fmctm1sw Ugly 750 K3 (project name: Mr. Yuk!) (Read 27761 times)

fmctm1sw · « **on:** July 22, 2011, 06:06:00 PM »

Picked this up a year or so ago and had it behind a few other projects. I figured it would be a simple task to clean it up a bit. The PO decided to go with a black color scheme. Well, black on the wheel hubs, fork ears, spokes and fork tubes. Then strip the things that are supposed to be black like the top clamp, handlebar clamp, and brake caliper. The pictures will tell the story. I started with the front wheel. I have decent chrome fork ears, uncracked fork rubbers, and a year correct fender. Hopefully by weekend end it will have a decent looking front end on it. Here's the start...

*edit* Dug up my "original" original post... http://forums.sohc4.net/index.php?topic=70864.msg787111#msg787111

fmctm1sw · « **Reply #1 on:** July 22, 2011, 06:09:19 PM »

Some cleanup. Some of it chipped off real easy, some not so much....

fmctm1sw · « **Reply #2 on:** July 24, 2011, 06:29:08 PM »

Put in some more work on the rim today. Between aircraft stripper, a brass wire brush, carb cleaner, a razor blade, and water spray I feel I got it back to respectability now. Some rough spots on the rim still, looks permanent

I figure I'll try hitting the spokes with some kind of emery cloth or something. Something I can hold in my hand an pull back and forth around them.

Dyrden · « **Reply #3 on:** July 24, 2011, 06:33:23 PM »

Thats a ton harder when the wheel is built. I bit the bullet and cut all the spokes on mine.

fmctm1sw · « **Reply #4 on:** July 25, 2011, 07:31:39 PM »

That thought crossed my mind but I think I'd rather have this pain than the lacing a wheel pain... I still have to do the rear wheel too..

Stev-o · « **Reply #5 on:** July 25, 2011, 07:54:57 PM »

Try steel wool on the spokes, they should clean up fine.

fmctm1sw · « **Reply #6 on:** July 26, 2011, 08:17:45 PM »

Here's some more front end work. I had a heck of a time getting the forks out. The fork ears seemed frozen to them. The steering stem was way too tight. I could hardly move it after I took the forks off. I'm going to take it apart and check the races, they may be grooved now.

fmctm1sw · « **Reply #7 on:** July 27, 2011, 05:48:27 PM »

The rear wheel will be as equal challenge as the front.

fmctm1sw · « **Reply #8 on:** July 27, 2011, 05:52:46 PM »

some progress

Pappykono · « **Reply #9 on:** July 29, 2011, 10:30:08 AM »

Looking good. I'd be interested to hear if after the effort you would consider re-lacing if you were to do it again.

I'm so looking forward to my first rebuild this Winter that I'm reading up and looking for as many tips as possible. Got a K4 that will show up next week.

fmctm1sw · « **Reply #10 on:** July 30, 2011, 07:11:15 PM »

Here's some more rear rim work. My excitement about how well the spokes cleaned up is tempered by the understanding they will probably rust right up when they get wet. That said, I'd rather have rusty spokes than the crusty, black, chipping paint that was all over them. There's still some stubborn spots on the hub, my main tactics were the aircraft stripper, soda blaster and garden hose on "jet" setting. The spokes (no quite finished yet) were done with a 1 inch strip of cloth backed 150 grit sandpaper I got at Harbor Freight fished around them like flossing teeth.

fmctm1sw · « **Reply #11 on:** July 31, 2011, 12:41:39 PM »

Finished up the rear rim. Not perfect but it's about as far as I'm going. Much more respectable than it was before. I used engine degreaser on the hardware in the first photo and a brillo pad after that. Rinsed with garden hose.

fmctm1sw · « **Reply #12 on:** July 31, 2011, 12:44:14 PM »

... and back on the bike. Plus a before/after...

fmctm1sw · « **Reply #13 on:** July 31, 2011, 12:48:28 PM »

Forks. They were black too. I used aircraft stripper on them also. The gel stuff worked better than the spray probably just because the gel goes on thicker. That stuff will do a number on exposed skin... I hit them with 0000 steel wool after stripping.

*edit* I just noticed something about my forks. There was some kind of repair done near the bottom of one of them. See it? Don't know the deal with that but hopefully it doesn't leak.

DedHed · « **Reply #14 on:** August 04, 2011, 09:52:48 AM »

Hey now!
I just replaced the fork seals on my CB750K4 and the uppers looked a lot like yours did .... Rusted to the headlight bucket ears. I hit mine with a little bit of PB blaster and a wire wheel on a drill. that basically took all the crusty crud off but did nothing to really get it off....

Yours look like they cleaned up pretty good.... Did you use the same stripper on the uppers as you did the lowers?
(There's a good joke in there somewhere about strippers and uppers I know.....)

Thanks
Phil

fmctm1sw · « **Reply #15 on:** August 04, 2011, 12:50:07 PM »

Quote from: DedHed on August 04, 2011, 09:52:48 AM

Hey now!
I just replaced the fork seals on my CB750K4 and the uppers looked a lot like yours did .... Rusted to the headlight bucket ears. I hit mine with a little bit of PB blaster and a wire wheel on a drill. that basically took all the crusty crud off but did nothing to really get it off....

Yours look like they cleaned up pretty good.... Did you use the same stripper on the uppers as you did the lowers?
(There's a good joke in there somewhere about strippers and uppers I know.....)

Thanks
Phil

I used that 1" cloth backed sandpaper on them along with a wadded up hung of aluminum foil. Very versitile, that sandpaper. It was at HF in a 4 pack of like 150/220/320/400 grit or something like that. Here's the stuff: http://www.harborfreight.com/20-ft-sanding-roll-assortment-96777.html I got fork seals on the way too. I'm worried about getting the seals in, did you slide them down over the top?

DedHed · « **Reply #16 on:** August 04, 2011, 02:09:25 PM »

No, I didn't slide them over the top, I removed the upper from the lower by removing the 6mm hex bolt on the very bottom of the lower. There is some very good posts about replacing the fork seals. I pulled mine out of the triple tree because I wanted to clean them up and I assumed it had never been done on that bike.

I have no clue when the or if the PO ever changed the seals out, when I drained the old oil, it was BLACK... I thought, ok.... I didn't know there was black fork oil.... some serious nasty stuff came out of there, I have all the insides nice and clean and most importantly, sealed up. It was not that much fun, like you I had to use a little field engineering to get those suckers out of the triple tree.... A short well struck dowel did the trick for me.

The seal replacement is not a hard job, the only issue I had was the 6mm bolt on the bottom..... I left my forks on the bile when I took it out.
Check this out.... it will help!
http://www.motorcycleclassics.com/multimedia/image-gallery.aspx?id=11492&seq=1

Again, some digging in the FAQ's should help a lot.
Phil

fmctm1sw · « **Reply #17 on:** August 07, 2011, 06:38:28 PM »

I now have tapered roller bearings on my steering stem. I got the stock races out without much trouble at all. Some taps on a long slotted screwdriver with a small hammer and a 4 lb sledge.

fmctm1sw · « **Reply #18 on:** August 07, 2011, 06:43:34 PM »

Removing the race from the steering stem was slightly more of a challenge but not really difficult at all. Same screwdriver and small hammer.

fmctm1sw · « **Reply #19 on:** August 07, 2011, 06:47:32 PM »

Getting the bearing onto the steering stem was the hardest part. I used a PVC pipe to tap on the sides of the bearing until it seated. I used the thin washer and the steering stops lined up perfectly.

fmctm1sw · « **Reply #20 on:** August 07, 2011, 06:54:12 PM »

Last shot of the front wheel. Hopefully the fork seal replacement goes as smoothly as the steering bearing upgrade went.

DedHed · « **Reply #21 on:** August 08, 2011, 06:50:16 AM »

Funny.... You're a little apprehensive about the fork seals and I'm a little apprehensive about changing the steering bearings.... I guess it all works out.
This week, I should be the proud owner of a new seatcover and a new tank. I am buying a mid-eighties tank to use while I figure out a way to bang a dent out of the original tank, and I used an Alabama repair kit (Duct tape) on the seat for about six months now....
Good luck with the for seals.
Phil

fmctm1sw · « **Reply #22 on:** August 08, 2011, 07:09:46 PM »

Quote from: DedHed on August 08, 2011, 06:50:16 AM

Funny.... You're a little apprehensive about the fork seals and I'm a little apprehensive about changing the steering bearings.... I guess it all works out.
This week, I should be the proud owner of a new seatcover and a new tank. I am buying a mid-eighties tank to use while I figure out a way to bang a dent out of the original tank, and I used an Alabama repair kit (Duct tape) on the seat for about six months now....
Good luck with the for seals.
Phil

Phil,

I destroyed that allen head bolt in the bottom of a fork tube I had and to this day haven't gotten it apart. This time I have an air impact wrench to use on these. If I can get the bolts out, I think it will go smoothly. My 550 seat cover came out pretty nice. It's in another build thread (a project on pause right now).

Regards, FM

fmctm1sw · « **Reply #23 on:** August 09, 2011, 06:12:46 PM »

Well, so far so good with the fork seals. I bought a HF air impact tool and fashioned a 6mm allen bit by cutting up an allen wrench. It made short work of the allen bolt in the bottom of the fork tubes (on the lowest setting). I can't say for sure whether or not I would have been able to get these out without the tool but I consider it a good investment. I made a quick cursory attempt to pull the seals out and they seem real stubborn. I just don't have any more time tonight.

DedHed · « **Reply #24 on:** August 10, 2011, 06:38:16 AM »

For what it's worth.....
I dis-assembled everything and cleaned as well as I could with a few shots of WD-40 and then some PB Blaster. I let that sit for a while I boiled up a big pot of water. Poured the hot water in a bucket and put both fork tubes (Seal side down) in the water.

After about 15 minutes, I could get my seals out, still wasn't easy but they did pop right out with damaging the tubes. I suppose the same method could be done with a heat gun.... I don't have one so I used what I thought would work... Now that I think about it, I may have read that here somewhere.

I've been looking around here for a suggestion..... I am going to chemically clean a tank that someone coated with a Kreem like goop.... Where the heck can you dump MEK? or Acetone? probably not a good idea to pour it out in the storm drain in front of the house.....
Phil

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Author Topic: fmctm1sw Ugly 750 K3 (project name: Mr. Yuk!) (Read 27761 times)