Topic: Can anyone explain this throttle spring?

[Bigmant]

Hey gang!

Just curious if anyone has any idea how this may make the throttle on a Cb750K feel as easy as a modern bike? My spring is SO heavy that my forearm is burning after about 20min. Wondering if this guy somehow figured out something clever!

[bryanj]

No idea but what is going on below?

[denward17]

No idea but what is going on below?

Air pods?

[Bigmant]

No idea but what is going on below?

Yea AirPods

[PeWe]

Stock spring is very hard on these carbs.
I found a weaker spring at Webike. Not cheap but painless throttling without the throttle grip rubber twist on its tube. Important that cables are routed so return will work by let go off the grip.

My Mikuni TMR32 carbs need very little to lift. Despite that a quick return.
I think my old Mikuni Smoothbore VM29 was easy to handle too.

[pjlogue]

I replaced my throttle spring with a similar length spring with lighter coils.  The throttle is much easier on the wrist now but will still return to a closed position if I let go of the grip.  I found the springs at Lowes.

-P.

[rotortiller]

There are also thicker grips available offering a better leverage however the wrist travel is longer with the larger circumference. And then there are those throttle brake thingies. Not a problem for some, as wankers do have a very strong wrist lol! 

[Phoenix]

I just stretched mine and it works fine.

[Bigmant]

I also found a similar length spring with a lighter compression at ACE hardware. Works like a charm. The bike in the picture though looks to have two springs, and the rubber is covering where the two hooks join. I’m amazed it worked so well despite looking somewhat janky.

[Oddjob]

Fit a small split ring, like a key ring, I fit some around 8mm and that reduces the amount of strength needed to pull it by around 20%.

I fit the ring around the lower peg when I have carbs apart, then just hook the spring onto the ring. If you haven't got carbs apart I suppose you could try and thread it on.

[Bigmant]

I’m wondering why someone would split the throttle springs into two springs and then tie it back with a spring. Why not just use a lighter spring?

[Bigmant]

Here it is again, I’ve brightened the picture up a bit.

[PeWe]

Spring is attached too high?
Here a set when I assembled them.
See green arrow where the pin is for spring upper attachment.
And yes, the seen holes in chromed parts have not yet got the bolts when photo was taken

[Steve_K]

Back in the 70s I had VWs and noticed the spring from the VW carb would fit,  Needed careful cable routing and it worked fine on my 74 CB550.  It might work on the 750s
Steve

[dave500]

also have clean bar end and throttle tube,use graphite powder not any wet type lube like grease or oil,be sure the grip end isnt fouling on the bar end or its flange at the cable housing,with a lighter spring it should feel much better and snappier.

[newday777]

also have clean bar end and throttle tube,use graphite powder not any wet type lube like grease or oil,be sure the grip end isnt fouling on the bar end or its flange at the cable housing,with a lighter spring it should feel much better and snappier.

Good point Dave.
I had a goldwing that I brought back to life that had a gummed up throttle tube and handlebar. I had to clean them out to get the throttle to operate correctly. Dry graphite powder is the best lube in there so you don't get dirt contamination gum.