Topic: Is it easy to refurbish the starter button switch - CB750K4

[andy750]

My starter button on the K4 (CB750) is starting to stick and on Saturday it got stuck while out on the road. Starter motor kep on engaging and I had to ride off with whirring sound...it finally came unstuck but cant have this happen again...I did use some WD-40 to alleviate the issue but its not going away....so how easy is to take apart and clean? change spring? anyone done this?

thanks
Andy

[IndyFour]

It's not hard to do, but the parts for the starter button are tiny and once you remove the little screw inside the controls that holds it all together, the tiny parts tend to fall out and disappear underneath something in your garage if not careful.    I just helped a friend of mine change out his bars and we had to take the switch apart due to the wire breaking off of the back of the switch as the controls came off of the original bars.  

If the button is really loose in the control (i.e. jiggles around alot in the control housing) then the spring is probably either worn or broken.  If it's just getting stuck when you push it in, then there might just be gunk in there, in which case a good cleaning would probably free it up I would think.  Once you open up the control and poke around in there, you will see how it works....it's pretty self-explanatory.  

My only word of advice would be to be careful prying the control housing apart, especially if your control wiring still goes through you bars.  It's easy to pull the little wire off of the back of that starter switch.....especially if the controls have been messed with before.

Good luck!

[mycb750k6]

If yours is the type that has the round black button slide in a clear plastic case inside, that case may have cracked, broken or started to disintegrate. I took a K6 switch apart and the plastic parts just fell out in pieces. I ended up replacing the entire bottom half of the switch. The earlier switches were much simpler and easier to fix. I would find out what you're up against before cracking it open. You can always kick start it.

[Alan F.]

I've probably got a decent horn button and spring from my old K3 controls if you think you'd like them I could have a look and bring them wednesday night.
-Alan

[andy750]

Thanks guys for the useful advice - I have this switch:

http://www.yamiya750e.com/index.php?main_page=product_info&products_id=927

Ill take a look and see and I have a spare bottom half I think (thanks Alan but I think I have enough spares). My wires run outside the bars so no problem there.

Much appreciated
Andy

[Alan F.]

 

[Old Scrambler]

Just for clarity........the K0-K3 models have common starter buttons and internals. K4 and up are different.

[rhos1355]

And don't, whatever you do, don't blow the bits all over your shop with a compressed air pistol, like yours truly here did "just to get rid of the dust a bit"
Spent a couple of evenings on my hands and knees looking for that tiny ball bearing that goes on the kill switch.

[Accolay]

I redid both of my electronic handlebar controls. Best to take the parts off over the kitchen table over a big bowl or something instead of in the garage and take lots of pictures, and put things in baggies. My only big problem was getting some very small screws out that were corroded into their holes. I found new ones at either Ace or TruValue and put them back in with anti-seize.

I took pictures of everything and even measured the ball bearings (all be it with an SAE ball bearing gauge). If you need pictures, let me know.

[andy750]

Thank you Accolay I am going to PM you my email address for some of these pics. Great advice - thanks!

cheers
Andy

[gnarlycharlie4u]

I recommend that you get yourself some "electronic cleaner."
it's an aerosol spray designed to remove dirt and moisture and completely evaporate.
when you put it all back together use a little bit of dielectric grease on your connections and in the switch and you'll be good.

If for some reason you do blow it and break or lose something, PM me.
I have a bunch of extra control switches that I have for parts/backup.

[andy750]

Thanks very much for the offer Charlie but I have a spare myself so hopefully Ill not need yours. Much appreciated.

cheers
Andy

[Bowswell]

Partsmore 6$ button and spring...
https://www.partsnmore.com/cat_index.php?model=cb750_sohc&category=electrical

[Accolay]

Hrm...just for future reference, do you think that Parts N More starter button/horn button would fit in the 550? Are the 750 and 550 buttons the same?

[weltzing]

hey i also am having problems with the start button not working, because i think i twisted the wire off the back, so i want to get the little screw out for the starter wire inside of the controls and its rusted in there and the phillips head is stripped so how did you get the screws out? thanks for any help



 

[Accolay]

I had one screw like that when I redid my controls. I already had my controls disconnected from the bike though, so I had more options for getting the screw out. I soaked in PB Blaster, put the body of the control between blocks of wood in a bench vice, and then used an impact driver.

But I suppose yours is still connected to the bike. Can you solder? Maybe you'll end up cutting the wires real close to where they terminate at the starter button, and then remove that from the bike to work on it and solder after you get it fixed (after buying new screws-I think I found mine at TruValue or Ace).Then you can use lots of ways to try and get the screw out: heat, drill, easy out, etc.