7.5 Mercury impeller

[shawn.54]

Looking to get new impeller for 7.5 Mercury sn 6241478 I boats lists 2 part numbers. How do I know which one and about what year is this outboard?

Thank you for help

 

[tpenfield]

47-89981 is the impeller that is listed for that engine.

 

[racerone]

There are 2 impellers listed for some motors.---Depends on the driveshaft diameter where the impeller fits.---Lower units interchange on these motors so you have to measure.

 

[tpenfield]

47-89981 is the impeller that is listed for that engine.

My bad . . . 47-89980 is also listed. You will have to measure the drive shaft (or maybe the old impeller) to be sure.

0.456" dia is the '81' and 0.438" is the '80'.

My old impeller actually had the number molded into one of the blades . . . needed a magnifying glass to read it.

Your engine looks to be a 1983 model year, so the drive shaft should be stainless steel.

 

[racerone]

Measure the driveshaft.

 

[shawn.54]

Thanks guys this motor was fogged carbs cleaned and stored in a heated garage for 10-12 years anything else I should watch for.

 

[tpenfield]

I had to replace some wiring on my engine as the insulation had rotted.

I would give the cylinders a good blast of fogging oil via the spark plug holes before you start it up.

Unless the fuel system was run dry before the layup, the carb and fuel bowl may be gunked up.

 

[shawn.54]

My uncle picked this motor up at a dealer at the end of the season had them put new plugs in and winterized and never touched it again I hope they drained carbs when they did that will check them out before I start it.

 

[shawn.54]

Put motor in barrel started on 3rd pull pulled lower unit the shaft is stainless.438 ordered impeller and waiting for that checked wiring As advised wires on kill button rotten looks like green tarnish eat it's way out. Touch jacket and it falls off. Did not get close look before rain can wire be replaced or do I need new switch. This is why I love this site a little heads up can save a lot of paddling. Thanks again.

 

[60sboater]

Your switch is probably ok...can be checked on ohms function of a multi-meter. My '73 9.8 had trash wiring;I replaced all of it from the stator downward. Look at some of the other topics related to impellers for details on doing the replacement job.

Check all wiring and connections and repair or replace as needed.

 

[shawn.54]

i was wondering if this motor had a trim tab on the anti cavitation plate if so I'm missing that part

 

[60sboater]

I just looked at my 1976 7.5 and it does not have one.

 

[tpenfield]

i was wondering if this motor had a trim tab on the anti cavitation plate if so I'm missing that part

No trim tab . . .

 

[shawn.54]

Was away from boats awhile thanks for the help

 

[shawn.54]

Have had a chance to run boat for two different trips runs like it is a new motor cold starts 2-3 pulls after that 1and go did find rotten wires on kill button both sides one that is ground left alone other side to cid box I slipped a piece of tubing over to stop it from touching shift leaver thanks guys you are always a great help.

 

[tpenfield]

That is great. I found rotten wires on my engine. . . Had to make a new harness and replace it.