changing 3000 rpm to 800 rpm

I have a 5 hp briggs and straton gas engine. The dealer said it turns 3000 rpm , at full throtle. I can't find it on engine but I assume he
is correct. I have a 3 inch pulley on a cintrifical clutch on drive shaft. I need this engine to turn a pump at 800 rpm. Can someone tell me what size pulley I need to on my pump? Any help would be greatly appreicated.
Tom Richards
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er wrote:

The diameter of the pump pulley needs to be 3000/800 times the diameter of the motor pulley.
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Sue

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11.25" driven pulley. 11 gets you in the ballpark
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Let's see if I'm thinking correct, (I'm sure if I'm not someone will let me know). You have asked a ratio question, simply divide 3000 by 800 to get 3.75. Multiply this by the 3 inch pully to obtain the size of the pully you need on the pump - 11.25 inches.
T Carter
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Two excellent sources for that sort of info, are the "Pocket Ref", and also the online or paper version of a McMaster-Carr catalog.
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