same model prop, different WOT RPM

[thosch]

Bought a replacement prop for the '91 90hp Johnson, same brand and model number as old prop. Old prop turned 5900rpm at WOT, new prop turns 5800rpm. Is 100 rpm difference within acceptable +/-? Nothing else has changed.<br /><br />Not really worried, just didn't expect any difference.

 

[vissertrades]

Re: same model prop, different WOT RPM

Just a different day could net 100 rpm difference. Water and ambient temps as well as lake conditions and fuel quality all play a role.

 

[JB]

Re: same model prop, different WOT RPM

Howdy, t.h.<br /><br />Why did you replace it? Could the old one have been a bit beat up, causing minor cavitation and more slip?

 

[ob]

Re: same model prop, different WOT RPM

What JB and Piet Visser said.If the old props diameter was just 1/4 " difference due to wear ,there would be an rpm difference,not to mention any suttle differences in the manufactured pitch.