Impeller drive pin/key

[trex014]

I am working on making a suitable replacement impeller for a mercury ke7, since paying $50 for an impeller is a little much for me.

I’ve found an impeller off of an 80’s Yamaha 6hp that is very close in size ( for about $10) but the Yamaha uses a drive key, where the Ke7 uses a drive pin. The new impeller has a plastic “hub” and the old has a brass.

I know they exist but cant remember the name, they’re a drive pin, with a T shape like a pin and woodruff key combined. Anybody know what they’re called or where to find them?

[dave-bernard]

KE7 used a needle bearing type pin as a key. laid on the flat.

[foot_doctor]

Yup, the Mercury drive key is .125” in diameter. I make them from 1/8 inch stainless stock that I buy from McMaster-Carr. I don’t trust the impellers that have plastic cores. After long-term storage, the rubber vanes adhere to the pump housing, and when they are forced to rotate, the drive key simply carves a slot thru the plastic hub, and the pump fails. The brass hubs live a long time. They are robust enough that they can be used to rebuild them like Brian Wilcox does for us. Get the brass hub one. Your engine is worth the extra investment. R.T.

[joecb]

What footdoc says could be true after long storage. However there is a solution to the problem. If you are handy with a file, you can make a “T” shaped key that will act as a full key in the plastic hub keyway and have the other end pin shaped to fit in the shaft pin hole.

Joe B .

[dave-bernard]

the drive shaft on the merc’s dont have a hole and use the pin full length.
as far as the impellers sticking just rotate the motor every 6 months.

[crosbyman]

I don’t recall exactly where…. but I seem to recall making T shape impeller key by using a proper diameter stainless steel flat head nail ..cut to length and grinding the flat head sides to make it T shaped.

…grind the head before cutting to length …easier on the fingers 🙂

Joining AOMCI has priviledges 🙂

• This reply was modified 4 years, 4 months ago by crosbyman.

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