Topic: CB360, CB400, CB550, CB750 Starter Button Fix

[Mikerts_Garage]

Hey Y'all,

Just thought I'd quickly share my experience fixing the starter button on my 1977 CB550F.

As many of you probably know, the starter button on a lot of the late 70's SOHC bikes use the brittle plastic housing. As such mine had mostly shattered after a few years of use.

Thankfully plastic brackets and such are easy to make now with the advent of 3D printing! So I took the broken scraps from the bracket and pieced together a model. I printed it on my Hictop I3 clone using the highest resolution it could muster, and a bit of PETG filament.

Here are a few pictures of the process and result:

The broken bracket that came out of the bike.

3D model of the bracket(available to download at the link below)

The new bracket right after printing.

After removing the supports.

Snapping the contact plate into place, this was the moment of truth as the print must withstand lots of bending force for this to work.

Don't forget to clean the contacts! This stuff works great.

Switch rocker installed.

Give the button and the detente ball a good greasing.

Button installed.

Bottom plate installed, this also required some bending, but not as much as the first plate.

All screwed into place 

Overall I couldn't be happier with the results, the button works every time and I no longer have to press it all the way into the housing to get it to work.

If you would like to download the model and print it yourself you may do so here

[Jerry Rxman Griffin aka MuthaF'er]

Good to see someone else now making the housing now. I don't know where our original guy went? Since you have the software and hardware would you be willing to print these out as long as it's worth your while?

[Mikerts_Garage]

Hey Jerry,

I didn't think about printing and shipping them. As much fun as that sounds like, there are services out there that are much better, faster, and cheaper than i would be.

I popped the file into shapeways and they would print and ship it to me for $19. That's a price I couldn't beat.

That's the lovely thing about having the file freely available, you can get the bracket in whatever material and color you want from whoever you want!

I thought it might be cool to see it printed in metal, but then I remembered it has to bend lol.

I love having a printer because I can produce the parts same day, I might have lost all the tiny switch parts if I had to wait a week for the parts to ship.

On a final note, I think SLA printing might be the way to go with this model as accuracy is paramount. I can't speak to the strength of that however since I don't have a SLA machine.

[HondaMan]

If you change your mind about making them...I'd be glad to have you list your wares on my website when we get it back up. No charge for that to you: just think of it as a way to 'pay back' to this great forum.

[Mikerts_Garage]

If you could order a bunch of them and stock them in your store for an even better price then $19/piece, that would awesome. I think you could find a service that would give you a bulk discount.

I'd like to have as many people as possible have access to this part for as little money as possible. If i could have hopped online and had this part shipped to me all said and done for $10 I would have been ecstatic

All that being said, you have my express permission to use my design on your store. All that I would ask is that you try to make it a good deal.

Hopefully the plague of broken start buttons will be no more lol.

[scottly]

I don't know where our original guy went?

I can't remember who it was that was already doing this. If anyone remembers, maybe send a PM to see if they are still around?

[Mark1976]

   I did this repair with the 3D piece a couple of years back on my (at the time) 76 550f, it cost me $22 for the piece shipping included. I'll be honest, it didn't fit that well into the housing (incredibly tight) and had to finagle with it in order to get it to function properly, left the hold down screw out, otherwise it would bind and stick. Your experience may be different, but if it were me, I'd by a replacement rh assembly, pricey yes, less frustrating, definitely...

[Mikerts_Garage]

Interesting, where did you get the part from?

I had a tiny bit of trouble snapping the contact board into place, otherwise everything went together very easy and worked without sticking.

If there is a different replacement design out there, I am not aware of it. I modeled this one using the remnants of my broken housing.

Also what replacement assembly are you using? I've thought about buying the one on 4into1, but from the pictures it looks a bit cheap compared to the original assemblys.

[Mark1976]

   It was from the individual that had done the original on here, it looked fine, and your right about the contact board being tight, it was (that may have been the source of most of the binding). But the box itself, once assembled, fit in the throttle housing very tight, which contributed to the binding of the starter button. I did insert the box before assembling just to make sure I had an idea of what to expect (there's even a video I watched of assembling and install on youtube) and even then, while the box itself it slide right in, there was nothing left over in terms of space. So it did fit eventually, but I was not able to use the hold down screw. $22 and a lot of head scratching and WTF moments...

[Mikerts_Garage]

Strange... I would be interested to compare the dimensions of the different designs. With how little space there is to work with; even 0.1mm difference could make it bind i would imagine.

If anyone has a lead on the original design I'd be curious to see.

[RAFster122s]

I think I recently ran across a fellow whom might be on the CX500 forum who is making very nice replacement starter and other function buttons for old bikes. They had a plastic part along with a metal embedded part on the underside. The CB bikes, many of not most of them were in his second design. The cross over between bikes was interesting.
His looked extremely well made and reengineered if you were going to do it right. I'm betting they will be expensive. I will have to poke around in a couple weeks when things aren't so hectic and I have some free time to look for the link or email I sent myself for future reference.
I bought a replacement control from JT Marks that was aftermarket of higher quality than the cheaper one commonly out there or the cheapest they offer or can get...
The one I got looks great and the pieces line up perfectly. Going to have to probably upgrade the left side as the difference will be easily detectable... The CB550 is waiting for it's turn to get some love and get restored/refreshed.

[ekpent]

Those little screws inside the controller holding those button parts together can sometimes be a real pain to get out. Metal is like butter and they can be very tight. Make sure you have a very good fitting screwdriver and good technique to avoid wallowing out the head. Not all 750's used the "box" so open yours up first to see what style of starter button mechanism you have first if you find a source and want to order one.

[HondaMan]

This whole discussion reminds me of my [former] career!
Interchangeable parts don't.
Accurately-built parts were until computers built them.
Computer intelligence isn't. 'Computer department' managers aren't, either.
Artificial intelligence actually is.

[Redline it]

i have a feeling nobody is gonna want to hear this 2cents worth, but here it goes, in the late 80s my cb400f 1976 lost the starter button capabilities and at the current time i found a commercial sized pop corn machine, on the side of the road, it was bouquet canyon, the kind at county fairs, it was huge, anyways the popcorn machine had some kind of electrical problem. and it was loaded with a row of switches toggle type. so i found one that had 3 wired and a spring return. it was a 110v switch. but i wired it to the 3 wires going to the start button and wrapped electrical tape around the square base so it would fit between the bars and the idiot light console. and it's worked since then. perfectly. starter never has had any problem. and it never "not" works like from dirty connection. i could take a picture of it and show it to anyone. if i ever needed to replace it, i don't have to open the right hand switch controls. it was last split second decision, it's lasted so far 30,000miles, with no sign of problems, you have to tape the bare screw on connections. a 120volt popcorn switch, who woulda thought?

it's on its second motor, the first, starter blew up, exploded and shattered the crankcases. not really. it is on the second motor now.

the popcorn machine stayed in the driveway for a year i took all the switches and cable pulleys and then one night a friend and i loaded it in my datsun 620 pickup, it was heavy just hanging on the edge of  bed, tailgate down, got going down a dirt road on my property about 40mph and started fish tailing as hard as i could till it fell out, it was pretty cool.

[Smudgemo]

You can get switch housings here:
https://www.shapeways.com/product/RDM6ZT62Y/cb550-starter-switch-housing-replacement?optionId=61704409&li=marketplace

[Mikerts_Garage]

I think I recently ran across a fellow whom might be on the CX500 forum who is making very nice replacement starter and other function buttons for old bikes. They had a plastic part along with a metal embedded part on the underside. The CB bikes, many of not most of them were in his second design. The cross over between bikes was interesting.
His looked extremely well made and reengineered if you were going to do it right. I'm betting they will be expensive. I will have to poke around in a couple weeks when things aren't so hectic and I have some free time to look for the link or email I sent myself for future reference.
I bought a replacement control from JT Marks that was aftermarket of higher quality than the cheaper one commonly out there or the cheapest they offer or can get...
The one I got looks great and the pieces line up perfectly. Going to have to probably upgrade the left side as the difference will be easily detectable... The CB550 is waiting for it's turn to get some love and get restored/refreshed.

This sounds very promising,  A well done rework of this starter button that maintains the original look and functionality would be worth investing in. Eventually all plastic(besides maybe fluorinated hydrocarbons) will turn back to organic goop or go brittle with time. I think we would all appreciate a proper metallic replacement, considering one of the best parts of these old bikes is their resiliency.

[Mikerts_Garage]

Those little screws inside the controller holding those button parts together can sometimes be a real pain to get out. Metal is like butter and they can be very tight. Make sure you have a very good fitting screwdriver and good technique to avoid wallowing out the head. Not all 750's used the "box" so open yours up first to see what style of starter button mechanism you have first if you find a source and want to order one.

This is so true, whatever alloy Honda was using for the switch housings is a bit soft, add some corrosion between the screw and the body and it can be deceptively hard to remove.

As for model years affected: usually the "simple" style doesn't break at all in my experience. usually its the later 70's bikes with this plastic housing. the fastest way to tell is to watch the headlight while cranking over the bike, if it stays on you have the simple button mechanism, if it turns off, you have this plastic housing.

[Mikerts_Garage]

i have a feeling nobody is gonna want to hear this 2cents worth, but here it goes, in the late 80s my cb400f 1976 lost the starter button capabilities and at the current time i found a commercial sized pop corn machine, on the side of the road, it was bouquet canyon, the kind at county fairs, it was huge, anyways the popcorn machine had some kind of electrical problem. and it was loaded with a row of switches toggle type. so i found one that had 3 wired and a spring return. it was a 110v switch. but i wired it to the 3 wires going to the start button and wrapped electrical tape around the square base so it would fit between the bars and the idiot light console. and it's worked since then. perfectly. starter never has had any problem. and it never "not" works like from dirty connection. i could take a picture of it and show it to anyone. if i ever needed to replace it, i don't have to open the right hand switch controls. it was last split second decision, it's lasted so far 30,000miles, with no sign of problems, you have to tape the bare screw on connections. a 120volt popcorn switch, who woulda thought?

it's on its second motor, the first, starter blew up, exploded and shattered the crankcases. not really. it is on the second motor now.

the popcorn machine stayed in the driveway for a year i took all the switches and cable pulleys and then one night a friend and i loaded it in my datsun 620 pickup, it was heavy just hanging on the edge of  bed, tailgate down, got going down a dirt road on my property about 40mph and started fish tailing as hard as i could till it fell out, it was pretty cool.

I have done this exact fix on my CB360, small toggle switch fit well in the housing and are almost better ergonomically. However, I don't like the look as much as the original button, which lead me to create this part.

[Mikerts_Garage]

You can get switch housings here:
https://www.shapeways.com/product/RDM6ZT62Y/cb550-starter-switch-housing-replacement?optionId=61704409&li=marketplace

So you're the original button guy! any chance you'd be willing to send me the model you used? I'm curious to see how it compares to mine dimensionally.

[Mikerts_Garage]

Sorry for the reply spam y'all, I stopped getting E-mail notifications for this thread for some reason. Thanks for all the input and whatnot! 

[MauiK3]

Great start!!