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)