Topic: Throttle Cable Replacement

[create2destroy]

Hello - Just joined up w/ the SOHC-4 Forum and first time question -

I have a 1972 CB500-4 that had a throttle cable snap on her. Prior to the cable snapping, the bike was running better than ever. I replaced both push and pull cables and replaced the tank. The tension on the pull is great and the throttle snaps back to start position perfectly (from all angles of front tire).

The only issue is that I need to have the idle pin cranked fairly high to get a good 2000rpm idle and when I put into gear and try to ride, the engine stalls.

I thought I possibly had the fuel lines from the petcock reversed but switching them didnt help; I think I may need to adjust the throttle cable to have more tension (keep the carb open) even at rest.

Any tips or advice? Things I am not thinking of?

Thanks in advance.

[MCRider]

Hands off, there should be NO tension on the pull (A) throttle cable. The twistgrip should have 1/16 to 1/8 rotation free of tension. The bell crank should be resting on the idle stop. Idle should be somewhere south of 2000. On a CB750 more like 1100.  Do not adjust the cable to hold the carbs open.  poor form.

Then you addres the other issues. If it dies when you put it in gear, the clutch is dragging. A proper adjustment comes first, and an oil change. If that doesn't help, you'll need to disassemble it and clean the plates.

Oh, and Welcome to the Forum!

[create2destroy]

Thanks for the advice.

Currently, I have no tension on the throttle -- there is that 1/8 rotation give on the throttle. I will check the bell crank again and make sure its resting proper.

I just had an oil change less than 60 miles ago and even the idle sounds off. This morning I was able to run the bike into second gear and when I slowed to stop and put into neutral, the bike died.

It really sounds like its not getting enough and running out of fuel.

Ill check the clutch.

- J

[MCRider]

Thanks for the advice.

Currently, I have no tension on the throttle -- there is that 1/8 rotation give on the throttle. I will check the bell crank again and make sure its resting proper.

I just had an oil change less than 60 miles ago and even the idle sounds off. This morning I was able to run the bike into second gear and when I slowed to stop and put into neutral, the bike died.

It really sounds like its not getting enough and running out of fuel.

Ill check the clutch.

- J

I'm a CB750 guy and hoping a 500/550 guy will step in.

Good on the oil. How long have you had your bike. A throttle cable snapping, does happen, but its pretty rare if the maintenance has been kept up. A dap of grease where the ferrule hooks to the throttle is about all. They do die from age as well as usage, though.

My comment was on the bike dying when engaging first from neutral at a stop. Other than that I'm not much help. Sounds like carb clean time. In the meantime I'd run some SeaFoam though the gas, can't hurt and likely to clean up something. Nothing takes the place of removal and cleaning though.

[iron_worker]

The CB500 clutches are known for going south. My cousin had the same problem. The actuator arm had cracked and was more or less just binding intead of pushing the clutch pushrod as it should. It would sort of lift the clutch but it still dragged a lot.

It's very similar to this:

http://www.ebay.com/itm/Honda-CL77-305-Scrambler-Clutch-Arm-Adjuster-Actuator-Thread-22841-266-000-/180870031130?hash=item2a1cb1a71a&item=180870031130&pt=Motorcycles_Parts_Accessories&vxp=mtr#ht_571wt_906

The outer housing had cracked and was allowing the arm to move laterally instead of directly in and out.

*edit* This is the actual part that had a piece of it missing near the open end

http://www.ebay.com/itm/Honda-CA72-CA77-CB500-CB722-CB77-CL450-CL72-CL77-Clutch-Adjuster-NOS-OEM-P1036-/110884601753?hash=item19d13cbf99&item=110884601753&pt=Motorcycles_Parts_Accessories&vxp=mtr#ht_736wt_954

*edit*

IW

[MCRider]

SeaFoam
http://forums.sohc4.net/index.php?topic=107393.msg1202098;topicseen#msg1202098

(Thanks IW re coments on clutch)

[iron_worker]

You likely have carb issues as well as McRider said.

IW

[create2destroy]

Thanks for all the advice.

Ill do some checking into the clutch this Saturday.

Ive had the bike for about 14 months - got it just good enough to run last summer and picked up from shop about a month ago; they rebuilt top end, carbs and performed general mainenance. However, the clutch was working proper and same w/ throttle cable -- the cable snapped in the switch housing. Im confident it was pretty old.

[MCRider]

Thanks for all the advice.

Ill do some checking into the clutch this Saturday.

Ive had the bike for about 14 months - got it just good enough to run last summer and picked up from shop about a month ago; they rebuilt top end, carbs and performed general mainenance. However, the clutch was working proper and same w/ throttle cable -- the cable snapped in the switch housing. Im confident it was pretty old.

Interesting. had a lot of work done. Carbs are so suspicious here. been many a bad story here about customers paying shops to rebuild the carbs and they barely touch them, if at all.

Age is now as serious a culprit to many failures as high mileage is. Wasn't that way 15 years ago. Is now.