Topic: What the heck is this screw thing?

[Ausmithe]

I have 2 72' CB500s. One is in pretty great shape and I ride it daily, the other is one I'm slowly tearing apart and fixing up. Well, this past weekend I noticed this screw adjustment on the underside of the right hand controls on the one I'm tearing apart, and it's an adjustment that I'm apparently missing on my daily rider. I never noticed that I was missing it, and so I'm wondering what it does, and if I need to replace it on the bike I ride daily?

[Jiminy Indy]

Cruise control - not recommended 

[Ausmithe]

Really? That's interesting. I looked it up on microfich but while it showed the part in the drawing, it didn't list a name for the function. It just listed the part as a screw or something generic like that. I've also looked through the maintenance manual and it's not listed there at all.

[MCRider]

Really? That's interesting. I looked it up on microfich but while it showed the part in the drawing, it didn't list a name for the function. It just listed the part as a screw or something generic like that. I've also looked through the maintenance manual and it's not listed there at all.

Yeah, aka throttle drag. Honda quit supplying them at some point. Liability no doubt. Don't know if its still available as a replacement part or not.  When they are adjusted for no drag, they can vibrate and fall out completely, may be what happened to one of yours. Its either on or off and difficult to adjust on the fly as you must let go of the throttleto do it.

Can be used to hold a high idle during warm up.

For cruise control (and warmup idle) purposes if you feel the need i would much rather see you get a VistaCruise or one of its many knock offs. For $12 to $20 you can have a drag that really works and can be turned off and on quickly without letting go of the throttle.

[Ausmithe]

Thanks guys, I am not really interested in having a cruise control feature anyway, as 90% of my riding is commuting around town, back and forth to work. But it's good to know what it is.

[lucky]

It was a great feature when on long rides.
It was great for warming up the bike on cold mornings.

You could operate it with one hand.
With thumb or thumb and fore finger.

[70CB750]

I will be adding one just like that for warm ups.

[Jiminy Indy]

Now my curiosity is up. My '74 has cruise control, but I think my '75 didn't. Anybody know for sure when Honda discontinued these?

[exf5003]

I think 74 was last year before discontinued, dont quote me though.
Its amazing for warm ups on cold mornings.  Just get RPM near 1000 and screw to lock in place and run back inside without having to worry about it.

[CycleRanger]

Now my curiosity is up. My '74 has cruise control, but I think my '75 didn't. Anybody know for sure when Honda discontinued these?

The "throttle friction adjustment screw" was discontinued in '75.
This change is detailed on the shop manual supplement for the '75 models.

http://forums.sohc4.net/index.php?topic=50339.0

[dave500]

i use it for cold warm ups,i think thats what it was for not a crude cruise control,you dont have to refiddle with the idle screw then.

[SohRon]

It was known as the Throttle Adjustment Screw and was used for setting various engine speeds during maintanance procedures, and was not meant as a cruise control, though it was used that way, too. It  was used on various models, but was discontinued in '75.  The '74 model is the only CB550 that used it.

I believe Yamiya has it in stock, IIRC.