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Repairing side cover on a '79 CB750L

2smoooth

2smoooth
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New here and I have looked over the various posts before deciding to throw this one out there.

I recently purchased a '79 CB750L and though the side covers are in generally good condition and include the Ltd badges, both the R and L side have missing (broken) posts on the inside for mounting.

Any tips on repairing these? I presume a restoration shop could also fix these, so if there is a recommendation there I would be grateful as well.
 
If missing the posts I can't imagine what even a restoration shop would use there.....................they would bite the bullet and pay to get complete covers. Customer charged accordingly.

You'll need at least new soft grommets, the old ones get hard with age and why the posts break off. I've heard that superglue mixed well with powder before it cures can make a good adhesive that has strength and lasts. Probably better for cracks rather than entire breakages though.

There are plenty of glues to glue them up but like with so many other plastics today the vast majority of them won't hold for spit. Forget epoxies. Soft oily based flexible plastic is a b-tch to glue successfully, ask the 3M Corp., and why their polyethylene glue costs like $85 a small bottle. On cars they use sonic welding to join the stuff, melted together.

I'm thinking those are simple K bike covers with an added emblem.............................
 
Thanks for the reply.. I am hearing some mixed reviews on repairing the existing posts (though I don't have the skills likely to fix them in the manner most describe.

I believe you are correct about the cover, and since I have the Ltd emblems I am on the lookout for a standard set of K covers with posts that are in tact.
 
I saw replacement posts for sale on ebay, don't look like original but could work. On different computer so I dont have link.
 
I can practically guarantee the epoxy will stick, but NOT HOLD if the rubber grommets are not dead brand new to be flexible enough to let the cover come loose easily. Older ones hold the covers tightly and the post WILL break off after a while. The covers are made of oily based plastic to make them flexible to a point and no epoxy on earth holds that type of plastic well at all, the dissipating VOC makes it let loose after a time. 3M makes a specialty glue for that but like $85 a small tube. If you ever do any type of gluing up on plastics of that type you plastic weld using sonic welding techniques, the same plastics are commonly used on cars on all sorts of body parts and how those get fastened down. Epoxying any of those is a quick lesson in futility as well. I used to watch the fails all day long when I was in parts; most people have not a clue of how to glue parts to last the long term.

I can just about guarantee failure using those posts in the link glued exactly like shown in the pics. If screwed into the bottom of the post they would hold but then you have a screw on the outside of the cover.
 
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I know this is an old thread, but wanted to add what I hope will be helpful advice. Go to your Honda dealer service department. Ask them if you could have some broken fairing/side cover pieces from wrecks they have repaired (ones with the typical Honda cover pins). Cut off the pins that you need as close to matching as you can. Obtain ABS plumbing cement (Amazon or local plumbing supply store) and some fiberglass cloth (auto parts stores around here carry it in small plastic bags). Glue the pegs in the appropriate positions and reinforce the joints with the cloth doped with ABS cement. Luckily, I had the pins on my '79 CB750F still as they were lodged in the grommets still (new soft ones are a good idea - lubricate with spittle). They seem to be VERY well attached now with the cement and cloth. ABS cement actually chemically bonds as the MEK and Acetone in it are ABS solvents. USE IN WELL VENTILATED AREA!
 
Iv repaired mine by using. Rhino glue, found out about this glue when repairing corvette back glass, glued it to convertible top over 2 yrs ago, must order online, very reasonable
 
I spray a little silicone on the rubber parts.....keeps them soft and prevents cracking. Older bike had a cover with one broken post....just drilled a small hole near the top of the cover and attached a cable tie through the cover on to the frame.
 
I've heard that gap filling super glue mixed with enough baking soda to make a paste that dries up like concrete can work. It's likely an issue trying to get the mix right and on the part before it dries too much. Using a bigger mass than needed to slow down drying may work.
 
I would suggest you hot weld new plastic on the covers and then shape them with a dremel tool. Should work just fine, plus the plastic welder is not that expensive. I have rebuilt many fairings and covers that were cracked, broken or just missing
 
When grommets get hard, replace them or plan on replacing the covers due to being lost by the side of the road. Lanyards are a good idea over the often-lost left side battery cover.
 
My '81 Custom had one broken tab on one of the covers. I drilled a small hole in the cover and ran a cable tie through the hole and the grommet. It was hardly noticeable and held the cover on securely. If more than one tab is broken, you may want to consider replacing the cover. If you can find one...dig deep.
 
It is actually much easier to just build up the plastic with new molden plastic with a plastic welder and then shape the material with a dremel, then paint it and no one will even know you had a broken part. I have done 100's of those type repairs from cracked fairings, tabs completely broken off fairings, and in fact even fairings that were completely broken. Welding plastic is the same as welding metal, and a good plastic weld is stronger than the original, as with metal welding.
 
One could look into the new 3D printing that they claim can be done with metal, just for Texas maybe? lol I have found if one constructs the tabs or repairs with the same type of plastic (very important), then the welded/moulded part should last as long as the original part.
 
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