jayzedkay
Club Member
For Information: it was mentioned earlier in the thread about issues if your shovel has the internal-throttle piano-wire cable and thinking about a carb swop to a cv and wanting to keep internal setup, and why wouldn't you? Possibly you're thinking of going to an early/internal setup for the cleaner look. i dug out my old photos of when i did mine.
this is how i tackled it.
i took a piece of 8-10, maybe 12mm? stanless-rod, chopped a little section off, drilled through for the cable(s) and drill/tap for the locking cap-screw. i made it as big as possible for integrity. that cap-screw is likely M5 or M6. I wanted as much purchase/grip on the cables as possible.
i had an inner cable kickin' about off somehting, a lambretta i think whose nipple fitted the k-cv perfectly, save chopping up the existing cable if it didn't work out. chopped a piece off long enough to couple the piano-wire to the throttle-linkage with room to spare. i think i initially made it super-long and trimmed it back once i knew where i was with it.
i thought of making a second-version 'swaging' the cables together and silver-solder/braze too make it bomb-proof and make a less bulky coupling. but it's never happend as above has, and works 100%.
firstly, setup 'loose' i backed off the cv-butterfly so it was fully closed; the idle-screw backed off so a gap between screw and throttle-cam as i'll call it. adjust the cables so you take up as much slack, but without opening the butterfly.
bit if dickin' about, snipe-pliers are your friend here. but straightforward enough. plus once you've had the carb on/off a few times over time. you get proficient at it.
now that it's setup off throttle. when you adjust the butterfly to be slightly open to obtain correct idle, it'll introduce a small amount of slack in the cable, so when off-throttle, it's definitely backed off and NOT held open slightly. leading to unstable idle, as i found first dealings attemping to setup with butterfly at idle-position.
Now, concerns of that little pig-tail, as seen above fouling on the spring of the idle-screw and giving hassles led me to wrap some stainless wire around it to make a 'sleeve' for it and keep it in check. See below. i thought of some heatshrink and whatnot, but thought it's bullshit.
my thoughts were now it'll simply pass alongside, granted it'll touch/rub, but it's never been an issue in 15+ years of being like this. foreddaboudit. also tidies up the mod somewhat - looks ok?
so off-throttle the coupling sits a little above the throttle-cam and is clear of everything. cushty.
w.o.t the coupling just stops before the idle-screw. see picture below.
adjustments could improve this, i.e. in the picture above, if adjusted so the coupling sat closer to the throttle-cam, but not touching.
then in the picture below the coupling would sit a little further away from the idle-screw, maybe giving more 'comfort' about it?
but to reiterate, in those 15+ years of this mod, it has never given any unpredictable/unstable/scary throttle issues whatsoever.
to conclude this mod has worked flawlessly for well over a decade, maybe closer to two?
i've never found the 'additional' spring on the cv to cause the throttle to feel stiff/hard in anyway, which i thought it might do.
early on i played with trying to adjust that spring to 'relieve' the tension somewhat or removing it altogether.
but without a return spring in the event of a broken/loose/snapped cable. there is possibility for the cv to force itself fully open, not ideal?
so i left it alone and wasn't an issue anyway.
it must be noted that the cv-spring WONT return the twist-grip. but internal-throttle doesn't return anyway and relies 100% on rider doing so.
i've never found that an issue. nice stable, repeatable idle.
in fact it's a plus. kinda like a cruise-control.
i often set it and loosly rest my hand on/around the grip on long rides. allowing a fatige free throttle.
never found it an issue, even under emergency stops/slowing down.
anyone that simply releases a throttle to 'return' it in the event of requiring sudden-shutoff, shouldn't be riding a bike?
anyway, finally i found that at w.o.t, max pos'n on the twist-grip, the cv wasn't fully open, it was like 90+%, which was perfect.
giving confidence that there was no stress on the cables/coupling if you happen to be w.o.t.
saying that, riding around i did some tests and found that the bulk, 95+% riding was less than half throttle. only up the steepest hills maybe you opened it up more or to overtake that sort of thing.
there was some other tweaking: i re-fabricated the outer-cable-grip bracket on the cv to better position/route the throttle-cable. apart from unlcuttering it by chopping off the return-cable-mount . i found that as oem-bracket. the angles weren't ideal for the piano-wire. it fouled somewhat on the rocker-box and also led to stressed cable with undesirable bend-radius. this may have been exacerbated by manifold-setup at the time; push-on adapter, no isolator-block etc? your experiences might be a little different?
so there you have it.
ditch those bulky controls and switchgear.
unclutter your bars and unclutter your mind.
internal-throttles' forever.
this is how i tackled it.
i took a piece of 8-10, maybe 12mm? stanless-rod, chopped a little section off, drilled through for the cable(s) and drill/tap for the locking cap-screw. i made it as big as possible for integrity. that cap-screw is likely M5 or M6. I wanted as much purchase/grip on the cables as possible.
i had an inner cable kickin' about off somehting, a lambretta i think whose nipple fitted the k-cv perfectly, save chopping up the existing cable if it didn't work out. chopped a piece off long enough to couple the piano-wire to the throttle-linkage with room to spare. i think i initially made it super-long and trimmed it back once i knew where i was with it.
i thought of making a second-version 'swaging' the cables together and silver-solder/braze too make it bomb-proof and make a less bulky coupling. but it's never happend as above has, and works 100%.
firstly, setup 'loose' i backed off the cv-butterfly so it was fully closed; the idle-screw backed off so a gap between screw and throttle-cam as i'll call it. adjust the cables so you take up as much slack, but without opening the butterfly.
bit if dickin' about, snipe-pliers are your friend here. but straightforward enough. plus once you've had the carb on/off a few times over time. you get proficient at it.
now that it's setup off throttle. when you adjust the butterfly to be slightly open to obtain correct idle, it'll introduce a small amount of slack in the cable, so when off-throttle, it's definitely backed off and NOT held open slightly. leading to unstable idle, as i found first dealings attemping to setup with butterfly at idle-position.
Now, concerns of that little pig-tail, as seen above fouling on the spring of the idle-screw and giving hassles led me to wrap some stainless wire around it to make a 'sleeve' for it and keep it in check. See below. i thought of some heatshrink and whatnot, but thought it's bullshit.
my thoughts were now it'll simply pass alongside, granted it'll touch/rub, but it's never been an issue in 15+ years of being like this. foreddaboudit. also tidies up the mod somewhat - looks ok?
so off-throttle the coupling sits a little above the throttle-cam and is clear of everything. cushty.
w.o.t the coupling just stops before the idle-screw. see picture below.
adjustments could improve this, i.e. in the picture above, if adjusted so the coupling sat closer to the throttle-cam, but not touching.
then in the picture below the coupling would sit a little further away from the idle-screw, maybe giving more 'comfort' about it?
but to reiterate, in those 15+ years of this mod, it has never given any unpredictable/unstable/scary throttle issues whatsoever.
to conclude this mod has worked flawlessly for well over a decade, maybe closer to two?
i've never found the 'additional' spring on the cv to cause the throttle to feel stiff/hard in anyway, which i thought it might do.
early on i played with trying to adjust that spring to 'relieve' the tension somewhat or removing it altogether.
but without a return spring in the event of a broken/loose/snapped cable. there is possibility for the cv to force itself fully open, not ideal?
so i left it alone and wasn't an issue anyway.
it must be noted that the cv-spring WONT return the twist-grip. but internal-throttle doesn't return anyway and relies 100% on rider doing so.
i've never found that an issue. nice stable, repeatable idle.
in fact it's a plus. kinda like a cruise-control.
i often set it and loosly rest my hand on/around the grip on long rides. allowing a fatige free throttle.
never found it an issue, even under emergency stops/slowing down.
anyone that simply releases a throttle to 'return' it in the event of requiring sudden-shutoff, shouldn't be riding a bike?
anyway, finally i found that at w.o.t, max pos'n on the twist-grip, the cv wasn't fully open, it was like 90+%, which was perfect.
giving confidence that there was no stress on the cables/coupling if you happen to be w.o.t.
saying that, riding around i did some tests and found that the bulk, 95+% riding was less than half throttle. only up the steepest hills maybe you opened it up more or to overtake that sort of thing.
there was some other tweaking: i re-fabricated the outer-cable-grip bracket on the cv to better position/route the throttle-cable. apart from unlcuttering it by chopping off the return-cable-mount . i found that as oem-bracket. the angles weren't ideal for the piano-wire. it fouled somewhat on the rocker-box and also led to stressed cable with undesirable bend-radius. this may have been exacerbated by manifold-setup at the time; push-on adapter, no isolator-block etc? your experiences might be a little different?
so there you have it.
ditch those bulky controls and switchgear.
unclutter your bars and unclutter your mind.
internal-throttles' forever.
Last edited:
