Finally Austin/Yamaha test drive time...clutching way off

[Seann17]

Weights are now at 77 grams each with rivets out. With clutch apart for good cleaning this time, sliding sheave doesn't "fall" from anything above 1/2 height. Soaked unit in my go to cleaner (Pine Sol) for 48 hours, scotchbrited everything, and it's still sticky near the top...part of my problem? Shouldn't the sliding sheave freely drop from all positions? So, shaft or buttons?

 

[maim]

sounding like you need to get the spider off and clean up the shaft as well as re bush it.

my youngest brothers sleds all do this for some reason. i think the humidity where he lives is a good part of it.

 

[74Nitro]

Weights are now at 77 grams each with rivets out. With clutch apart for good cleaning this time, sliding sheave doesn't "fall" from anything above 1/2 height. Soaked unit in my go to cleaner (Pine Sol) for 48 hours, scotchbrited everything, and it's still sticky near the top...part of my problem? Shouldn't the sliding sheave freely drop from all positions? So, shaft or buttons?

Normal. Yours has the cam sliders on one side that have an 0-ring in behind as cushion. That causes a little drag.

 

[Seann17]

Tried the car this morning with top weights out...I would have to say zero difference. Still have to rev it to 3500-4000 to make it move. I guess what I'm really after here (for starters) is like my old EZ-GO golf cart...as soon as you introduce throttle it just pulls away, no noise, just motion. The question is, how can I make this car do that? I'll worry about the performance angle later, initial driveability is what I have to focus on right now. Any "next steps"...I'm all ears. The car has been accepted in the 2025 Cobble Beach Concours in the "Modern Interpretation of a Restomod" class.
Thanks,
Seann

 

[Srxspec]

How tight is your belt? Belt deflection will affect how/when everything moves. It'll never be like a golf cart, a golf cart uses an electric motor to spin the engine and then a clutch with no spring when the engine starts moving, that won't work with this power plant, because as soon as you'd start then engine, you'd be driving away as the clutch would be engaged.

 

[Seann17]

I get the difference with the cart mechanicals, but a happy medium between the two concepts is what I'm after. Holding the car on the brake to start, with movement when the brake is released (clutch engaged) would probably mean a cold start/under 1500 rpm pull away. I'm playing with obvious "non sled" thoughts here, but just for r & d...how can I get this clutch to engage at 1500-2000? Possible...yes or no? I can roll the car with minimal "belt drag" on the primary...belt sits about flush with the secondary after running.

 

[Srxspec]

There's something wrong with your primary if you have the short spring in, tip weight removed, and still seeing 3500-4000 rpm egnagement. First thing is, it doesn't matter where the belt sits in the secondary, that's a useless way to judge belt tension. Adjust the belt tension until the car tries to drive away at idle (what we would call "creep" in a sled) or until it "squeals" from being too tight, then loosen slightly (if it uses the Yamaha secondary loosen it by removing 0.5mm of shim). You'll never get 1500 rpm engagement, you can likely get low 2000s, but it may not be possible with typical "sled" settings/components.

 

[Srxspec]

Shoot some pictures of your clutches with the belt installed, I'd like to see the setup.