Throttle spring

[darvi]

Hi has anyone found a lighter throttle return spring for a 750 four as I’m finding it a bit heavy for my aging wrist all new cable linkage free and lubricated closes fine just to heavy for me

[K2-K6]

I don't recall anything of this type product, even when contemporary and through to now.

Quite understand the feeling you describe and, often mentioned as reality of owning one on here and other sources.

Some suggestions that may help.
I use silicone oil for cable lubrication successfully (motorcycles, bicycle cables etc) as it works most effectively with the materials used in bowden cables used on these, doesn't deteriorate the linings, if in place. Also all but eliminating any chance of moisture into the cable longer term.
Have the cables been set with enough slack, Honda manual specifies something in the order of 15 degree twistgrip rotation allowance for correct operation, which avoids conflict between the two cable compromising friction and so weighting.

The grip along with gloves can play a significant part in physical muscle fatigue too. I'm particular in minimizing grip diameter, along with grip "tack" that avoids the need for higher muscle tension to even hold the grip, before even considering the effort to turn it. Can make substantial difference to effort here.

Appreciate it maybe on std grips for period/authenticity etc, but more shiny and worn surface makes a big difference to your ability to endure the the traction needed to hold the grip where you want it during use.

Free choice, I use grips that are more tacky, thin gloves that don't bunch to force the hand into trying to hang onto a increased radius, and allow the hand to be more just rested onto it with little effort.

Perhaps something in there to consider or help out.

[exvalvesetdabbler]

The only thing that came close is a barrel spring used on Weber carburettors and might need to re bend on one end to get the length right.

The other option I have been looking at for a set of 400/4 carbs that I'm rebuilding is to make up a small extender for the spring to reduce the tension. First with a piece of stiff wire to evaluate the required extension and then make something a bit neater out of sheet metal with two holes of suitable diameter, one for the carb end and a smaller hole to hook the spring onto. This is my preferred option because the next person that comes along can simply remove it if they don't like it.

Could also play around with various sized washers.

Regards
Dave

[Bryanj]

Only thing i can suggest is a box of assorted springs, usually see them at stem fairs/rallys in this area

[Oddjob]

I've done this on a few banks of carbs now and it tests out as working. Remove the bottom of the spring, fit a small split ring like you find on keys, reattach the spring to the split ring. I tested both versions with a spring balance and there is an approx lowering of effort needed of around 15-20%. That was on banks of 500/550 carbs, I'd imagine that it would be about the same for 750s as well. Easier done when you're building the carbs, but still doable after just trickier. A split ring of around 15-20mm seems to be ok but have a look at the gap available before buying. Leave the top of the spring still attached and see what the gap from the bottom hook to the pin as a gauge on how big you can go, you still need some tension to stop it coming off.

[darvi]

thanks to all for there input it gives me some suggestions to try