Correct Impeller kit?

jdaher

Seaman
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Jun 1, 2006
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62
I ordered an impeller kit for my 1998 Force 90 hp outboard a few weeks ago. I got the Sierra 18-3570 from iboats. Is that the right one? I already put it in, but it is still struggling to get water out the tell tale. Thanks!
 

jdaher

Seaman
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Jun 1, 2006
Messages
62
Re: Correct Impeller kit?

I emailed someone at boats dot net and they said it was part number 43024A7. Similiar to Sierra 18-3570, but looks like a few extra things.
 

emoney

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Jul 19, 2010
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Re: Correct Impeller kit?

DId they say the impeller was the same? How are you testing it, in the water or with muffs?
 

jdaher

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Re: Correct Impeller kit?

DId they say the impeller was the same? How are you testing it, in the water or with muffs?

Iboats said sierra 18-3570 first time i chatted with them the day I bought it. I chatted with them today and now they said they don't carry the kit for my outboard....:facepalm:

I emailed boats dot net and they said it was part number
43024A7.

I don't know if it is the same. I'm testing it with muffs.
 

emoney

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Re: Correct Impeller kit?

When you put it in, did it have a nice, snug fit on the driveshaft and did you have to twist the tines to fit into the housing? If it was loose anywhere, probably want to do a "do-over" on this one. IF not, do you have access to a very large trash can or 55 gal drum that you could submerge the engine in? I've had 'em struggle to spit water on the muffs but pee like a champ when in water. The best thing, however, is to get a infrared thermometer and check the actual temps on the heads when she gets warm. Lots of people rely solely on the water coming out of the telltale but still end up with an issue.
 

jdaher

Seaman
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Jun 1, 2006
Messages
62
Re: Correct Impeller kit?

Yeah and I had to twist the tines as I put it in.

What I'm worried about is that the
43024A7 kit has an extra piece (top left in pic) that is pretty big. Also two cylinders extra
43024a7.jpg


Here is a picture of the Sierra 18-3570:

41greEpoIfL._SL500_AA300_.jpg
 

emoney

Commander
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2,551
Re: Correct Impeller kit?

They're just two different kits, but probably for the same model. The point is, as long as you didn't pull those "extra parts" out of your boat and discard them, meaning you replaced the parts with new parts that were in your kit, then odds are you have the correct stuff. If you didn't need those "extra parts", doesn't matter that you didn't have them. Have you checked your thermostat for proper operation? What caused you to order this kit and start this project anyway, was it overheating or you didn't like the amount of water flow coming from the Telltale? Just changing the impeller, they probably use the same impeller for several different models.
 

jdaher

Seaman
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Jun 1, 2006
Messages
62
Re: Correct Impeller kit?

How do I check the thermostat? I've had the boat for 7 years and only had it replaced the 2nd year. It just didn't seem to be spitting out water like it used to.
 

roscoe

Supreme Mariner
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Oct 30, 2002
Messages
21,657
Re: Correct Impeller kit?

The '98 Force 90 used a different lower unit.
No aftermarket manufacturer lists an impeller or a water pump kit for that motor.
Iboats sells aftermarket parts.

If you want the correct part, with all the parts, you buy it from a Mercury dealer.
Part Numbers : 43024A7, 46-43024A7, 4643024A7 are the Mercury part number.


The 18-3570 kit they sold to you is an aftermarket kit made by Sierra, and doesn't have the pump base, the grommets, the drive key, or the bolts..
This pump is the equivalent of Mercury part number
817275A2

And will fit these Mercury motors.

40 (4 stroke)(4cyl) Bigfoot, OT228405 & Up
50 (4 stroke) 935cc Big Foot, OG231123-OT178499
50 (4 stroke) 996cc Big Foot, OT178500 & Up
60 (3 Cyl.) Bigfoot, OD000750 & Up
60 (4 stroke) Bigfoot, OT178500 & Up
65 Jet, OC283222 & Up
70 (3 cyl.), OA996142 & Up
75 (3 cyl.), OC222000 & Up
75 (4 Stroke), OG960500 & Up
80 (3 cyl), OA996142 & Up
80 Jet, OD283222 & Up
90 (3 cyl.), OA996142 & Up
90 (4 stroke), OG960500 & Up
100 (4 cyl.), OB209468 & Up
115 (4 cyl.), OC100000 & Up
125 (4 cyl.), OD283222 & Up



Mercury calls for part number 43024A7 for your motor, and they sent you a pump
that equates to Mercury part number 817275A2.





For the thermostat, you take it out, set it in a pan of room temp water and put it on the stove.
As it heats, is should open at 130*.

A Merc dealer charges $17 for that thermostat. (aftermarket is $32)
 

jdaher

Seaman
Joined
Jun 1, 2006
Messages
62
Re: Correct Impeller kit?

So you are saying they are the same, but the sierra kit doesn't include all the pieces???

From this picture:
17.GIF

I don't have the piece labeled 31. Seems like that is why it would work better in a tub or in the lake.
 

roscoe

Supreme Mariner
Joined
Oct 30, 2002
Messages
21,657
Re: Correct Impeller kit?

18-3570 and 817275A2 are the same, except for the missing parts.

But your motor calls for part number 43024A7.

THe same? no.

Close? yes.


They used a lot of misc parts from the warehouse in 98 and 99.
Things they could use to get by, as the Force line was being discontinued.
 

jdaher

Seaman
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Jun 1, 2006
Messages
62
Re: Correct Impeller kit?

What would happen if the part labeled 31 wasn't installed?
 

jdaher

Seaman
Joined
Jun 1, 2006
Messages
62
Re: Correct Impeller kit?

:redface:I do have part 31. I took the lower unit off to inspect. It was stuck on the top inside.
 
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