Hotrod test wheel

[Skoontz]

I could not find a test wheel anywhere, so, decided to get creative...

Took a 9/16ID hunk of pipe, a deck mount for a 1/2" pipe, then centered and screwed it to a 6.5" Skill saw blade rated for 8400RPM. It holds the engine to 7400, does not cavitate and balanced very easily on my lawn mower blade balancer... total cost, $23

[Aeroliner]

I took my mercury test wheel and had a shear pin grove cut in the back side. Did it with a router and it works fine.

[Boatnut]

My yamy 90 3cyl 2str has a shiftable case but i'm still missing a couple of bits under the cowl and have it fixed in foreward gear. floating in tha water is not it's strong point. i like to warm it on the trailer but need a test wheel. As far as getting most of tha cool sruf you guys in tha states can get, in australia we might as well be on the moon.

How would a bloke go about calculating the size of a test wheel. it'll probly be easier to make it here than buy it but i see workin out the size to be the tricky bit.??????????

[Skoontz]

Craig Dewald told me simply to do similar to what I did. So, for you, find something with Yamaha splines on it, perhaps an old, trashed aluminum prop. Cut the blades off. Then get a 1/4" piece of aluminum sheeting, and cut it the diameter of the propeller you run. Place 4 slices in the sheeting, 90° apart from one another. You'll need to bend those outward to adjust RPM to what you normally run at at wide open throttle. Carfully tap each of the 4 slices so the test blade moves outward. Then, back the boat in, and slowly run the throttle up. If keep bending the blades outward until your high end RPM stops where you run at.

The other way is instead of slicing the wheel, you can place bolts 90° apart on the outer portion of the wheel you made.. you'll need to adjust with longer or more bolts until RPM reaches the number you want.

you can also find test wheels on E-bay but the way some of these people bid you would think they are gold rather than aluminum. I stopped bidding at $100 for one that fit a hot rod foot, and I thought that was rape artistry had I won it.

[bill boyes]

I got mine from Tom Johnston. It is a copy of the old Merc one. Works great on my Yamato's 102/302's. Don't remember what I paid. Think it was about $35.00

[Skoontz]

Bill:

Would he have test wheels for the hotrod foot? And could you provide any contact info?

[bill boyes]

It should fit the Hot Rod case shaft dia is the same i think. Will send you a pm with TJ's phone nbr.

[Boatnut]

Skoontz and bill, Thank you for the replies, Skoontz i think your onto something. i just happen to have the old alloy prop i got with the mota so i think i will start cutting and welding. thanks for the tip.