1983 CX650 Eurosport restoration thread.

[Tim-That CX Guy]

This post is about repairing broken plastic tabs, so I'm going to include Larry's email text as well.

"After I finished the zinc plating 3 days ago, I had time to start figuring out how to rebuild the tabs on the handle bar cover. This has proved to be a challenge. It's going to take a couple or more emails to explain and show you what I've done and where I hope to end up. So, this may not be ready to post since I haven't gotten the final technique verified as to how I want it to end up. So sit back and be patient.

First was to sand and prep the areas. Then I found a round brass rod with the proper diameter to lay in where the holes needed to be. Luckily the base of the original holes were still there. With the rod in place I cut and made stiff paper backings where the tabs need to be flat and taped it all in place. With the set, I used a 2 part plastic repair that's made for difficult plastics. One side went well and bonded. But the other side kept falling off when it was moved a bit. So with the bonded side, I used a molding material from the PlastiFix kit that creates forms when it's heated up in boiling water and pressed in place. This allowed me to mix more compound and build up the back side to make it more ridged and secure. It worked well on that side. Yes, there's going to be a lot of die grinding to bring it to a smooth form."

 

[Tim-That CX Guy]

"My main concern was that the first compound I used cured very hard and doesn't leave and room for flexing if needed. And the fact that the other side tab I had formed keeps coming off when bumped or worked with no matter how I prepped it and tried again. So I got your original cover with the switch hole in it and used the mold I had made to use a different compound that's more flexible as a test. It bonded great and was more forgiving if it was put into a stress situation. I only did the first layer to form the tab as a test to see how well it bonded. After curing overnight, I have not been able to pull it off no matter how hard I pull on it or bent it. I will be adding another layer to the back side like I did with the other compound just to be safe.

With that test result, I will be forming the other side tab on the new/used cover so I can make molds of it like the other tab and use that to use the second compound as the permanent repair. Yes, I will need to grind off everything I've done and start over. But in the end I think it's worth it. One tab holding and the other one not is not confidence building!

The reason this has taken me several days, and more days to come, is that the compounds need to sit for several hours, or cure overnight to be fully secured. This is a time consuming process to put it mildly!

These two pictures show the new compound and how flexible it is under bending it.

BTW, when I had the first tabs done on the cover, I set it up on the bars to see how it fit. Due to the brake hose being a bit too short and sitting higher than it should be, I did the best I could to make it clear the fork bolt, the cover would not sit down all the way as it would rest on the brake hose. I'm hoping I can work this out later when the cover repair is finished without having to buy a new hose. [Note- I have an aftermarket steel braided brake line.]

Well, that's the update for the last few days. I'll keep you up on it all as it progresses. As I said, this is a slow and time consuming process. It'll be better than what I did on my Euro. I just used wide washer to secure the cover!"

 

[budman]

Way to go Larry!!!

 

[Tim-That CX Guy]

"This morning I came up with a better idea for making the molds. I used non hardening clay and warmed it up a bit. It formed much better and allowed me to make it deeper so I can do a tab all in one shot. The mold was taken from what I had done on the new cover, and then transfer it to the old cover after I had cooled it down in the fridge to harden it a bit. As you can see, it worked well. I let it cure for an hour or so and pulled the mold off and trimmed the tab up. Then I test fit it on the bike. I had to turn the brake hose down to get it on and it fit just fine, but the hose is really tight that way. But since I hadn't let it cure overnight, it's just a test, the tab pulled loose at the inside edge. No big deal though. I'll put more bond in there and let it cure tonight. The added outer thickness allows the bond to the outer upper base and adds a lot more strength.

If the tab secures itself better overnight, I'll continue on and let you know how it goes."

 

[Tim-That CX Guy]

Fairing plated bits on, lights working.

 

[budman]

Nice... looking like a moto baby!

 

[Tim-That CX Guy]

Fairing was a smidgen off canter.
"Since I had extra time, I got back into figuring out why the fairing wasn't sitting level when I closed it. After a lot of measuring and checking, I had to take the mounts back off. I mocked them up on the old triple and found a way to straighten the mount so it was level again. Took a bit, but it's level and true again. Hopefully this is the last of the twisted/bent parts from the previous accidents. Now I can assemble everything for good!

The first picture is what it looked like before I started working on it. But it was over to the right a half inch more than what I have demonstrated here. It's now sitting level as you can see.
This was the mock up to get it straight and true again."

 

[Tim-That CX Guy]

"I spent some time yesterday testing the welder and trying to figure out how I was going to set up so I had a flat side that sits against the bar clamp.
Today I tried a few things that didn't work. Then I tested welding on a piece of steel, and the plastic just peeled right off. So I cut some sheet metal in the shape of the tabs.
Then I measured and cut a stirring stick to fit between the two sides and JBWelded the steel tabs to it. This gave me a secure area to start welding the plastic in and know where the tabs belonged.

I need to say, I am so glad I have the old cover to practice with! It took quit a bit of practice to get the process figured out. Especially with the tip of the welder being long and flat. I made some mistakes, but figured out the best angle of attack in the end. It's not pretty, BUT, it's bonded and solid! I've pulled and twisted it hard, even tapped it with a small hammer, and it did not come off! I did some initial grinding and sanding to shape it afterwards. This will all work out well when I get the process refined.

I'll remove the other tab I made with the 2 part compound, (btw, it did NOT stay secured) and practice some more on that side tomorrow. I think it will go much better. I'll turn the heat down next time so it doesn't burn and discolor the filler.

Well, that's it for the learning curve for today."

 

[Tim-That CX Guy]

The two part system wasn't going to work on the tabs, so, plastic welding.

"Today's practice went a bit better. Learned a few more tricks of laying the molten plastic on. And lowering the temperature helped too. I tested with grinding and sanding it to shape afterwards, and it sands well. This will make the final shaping easier since I'll be able to put it on thicker and grind it. Just for looks, I sprayed a little black on it and set it on the bars. I'll use a flatter black on the final cover. (this picture was before I sanded and shaped it smoother) But so far, it's going well. It's just a pain getting into the small tight area with the long flat tip of the welder. I'm thinking of making a smaller and rounder tip for the welder. Not sure yet.

As I mentioned, the 2 part compound didn't stick. It pealed right off in one piece.

Next up will be to grind off the first 2 part compound I put on the new covers tabs. That stuff stuck well, but has no flex to it. And I like the idea of the welded bond being melted into the original base plastic."

 

[Pushrod]

To be honest, spending the better part of an hour following this thread was more productive than the last therapy session I was in. Was there music?

 

[Tim-That CX Guy]

I cannot even begin to appreciate what Larry is bringing to the table here.
This is hours of work on a part that not only cannot be seen, but literally doesn't impact whether or not the part doesn't fly off the bike while riding at combat speed.
Without the tabs, the cover still remains in place because of the ignition switch. The cover just wriggles and rattles. I know this because I ran my wedding track day without these tabs and without secondary tabs that I screwed in later to stabilize the cover.
This whole exercise is about knowledge, and he's sharing it with all of us.

 

[budman]

No doubt!! Really cool stuff Tim.... and Larry

 

[Tim-That CX Guy]

"Ok, the tab repair worked great this time and it held up well when tightened in place. I need to add more plastic to one side of it to make it wider. The holes are even on both sides and in the correct spot. So my pattern guide must have been misaligned while I was welding and didn't notice it. This will be an easy fix.

What I have found though, is the gaps between the cover and the gauge cluster are not the same. I've done some checking, and found that the metal rack that this all bolts to must be bent or twisted a bit. Loosening the top mounting bolts lets me twist it so the gaps are even on both sides. But, you know I can't cheat that way! I'll pull the cluster off and see if I can find where the rack needs to be straighten and do it right. I hope I can correct it without having to pull all the wiring harness out! I'll work on that after I send this. 1 step forward..... you know the rest!

Update when I make some more progress."

 

[Tim-That CX Guy]

"After removing the fairing, headlight and gauge cluster, I was able to pry the rack around in a better position. I didn't want to pull the rack off because that would involve the full harness and the brake hoses. In the end, I'm happy with the way it's all sitting now. And yes, I did use the oversized holes in the upper tree where the rack bolts into it to do the final adjustments. This may have been the intent from Honda all along. But it's all back together and lined up. I still need to add more plastic to the right side tab and then sand it all smooth so I can paint it black. That will be for tomorrow. I've had enough for today."

 

[Tim-That CX Guy]

"Well sir, this is the final update on the bar cover repairs. As always, the more practice you get with something, the better things go. With yesterdays repair coming out so nice, I HAD to improve the left side tab as well as widening the right side today. It took a while, but I'm very pleased with the results. They are both wider and thicker than the original tabs.
This evening I did the final shaping and sprayed them with a flat black plastic bumper paint. BTW, the cut on the front lower edge in picture 1 was there when we got this. I'll be bonding it with Weldwood contact cement.

That's it for this part of the project. I need to spend a couple days cleaning up the mess and putting things away to get the work benches and shop calm and organized again. Not sure where I'll go from here, but there's plenty to choose from."

 

[Rtmac]

Great job!

 

[Tim-That CX Guy]

After a major garage clean up and knocking out a set of carbs for another CX guy, work begins again.

 

[Tim-That CX Guy]

Aaaand the rear fender plastic is delaminating.

 

[Tim-That CX Guy]

Tank has been permanently sealed with POR 15.

Now, prep for paint.

 

[Tim-That CX Guy]

Tank nearly ready.
The rough spot on the top is from rust caused by water getting underneath the tank label.