Has Mercury Changed Impeller Materials

[mpsuda]

Motor 1983 V-150 Black Max

Has Mercury changed the rubber compound of their impellers?
My original impeller lasted a very long time. Taking set did not seem to be an issue.

I think original impeller was 47-89984 and now it is 47-89984T4.
What is the difference?
I thought it had to do with the hub (fiberglass vs brass).

Are any aftermarket impellers more durable?
How about Mallory or GL Marine?
I have read that some people don't think that highly of Sierra.



Details:

1983-1997 406 hrs original impeller. We replaced it for preventative maintenance not because we had a problem.

1997-2002 76 hrs. In 2002 first time out after storing for the season the high temp buzzer goes off when running on plane. Tell tale stream looked good but hot. Replaced impeller and overheating problem corrected.

2002-2008 50 hrs. Again first time out in 2008 storing for the season the high temp buzzer goes off when running on plane. Tell tale stream looked good but hot. No water flow coming out upper water- exhaust ports when boat is on plane at normal rpm. At higher rpm some water spay comes out but not good flow.

Plans are to replace impeller and increase preventative maintenance replacement schedule.

Thanks,

Mike

 

[CraigC]

Re: Has Mercury Changed Impeller Materials

I don't know for sure if they've changed the material or not, but I know it's fairly standard practice to change it every 2 years if it needs it or not. I personally run a water pressure gauge and even though I only average 40 hrs a year (bass boat) I change my impeller every spring because of a situation that I witnessed with my friends Merc. (story below). Well that AND the fact that it's cheap insurance to not overheat and ruin the powerhead. Parts are cheap and if you do it yourself it takes very little time.

Here's that story: He put a new impeller in, only used it btwn 1 and 2 hours that spring, then he shipped out overseas (military). When he came back 2 and 1/2 years later he took the boat out of the garage, and it needed a new impeller - he had no tell-tale stream at all! Sitting in the same position for extended period of time killed it.