Piston Kits & Ring Sets, WSM

Model/Year Piston Kit W/Rings Ring Sets Only
15 hp 94-04 Mercosil Block 100-04K 200-04
20 hp 72-79 100-05K 200-05
20 hp 94-04 100-04K 200-04
25 hp 94-04 100-04K 200-04
25 hp 84-86, 30 hp 84-86 Mariner only 100-801K 010-901
20 hp 94-07, 30 hp Jet 98-07  100-06K 200-06 
35 hp84-89 Cross Flow W/Boost Port High Dome piston not available,
Can use Low Dome Piston 100-15
N/A  200-15 
40 hp 72-83 Cross Flow W/Boost Port High Dome piston not available,
Can use Low Dome Piston 100-15
N/A 200-15 
40 hp 94-07  100-06K  200-06 
40 hp 94-07  100-06K  200-06
40 hp 90-97, 45 hp 86-89 (Inline 4) 100-05K  200-05 
50 hp 84-90 Cross Flow W/Boost Port Low Dome  100-15K  200-15 
50 hp 70-85 (Inline 4)   100-05K  200-05 
50 hp 91-97  100-07K  200-07 
50 hp 98-Up, 60 hp 98-Up  100-06K  200-06 
60 hp 84-90 Cross Flow W/Boost Port Low Dome  100-15K  200-15 
60 hp 84-90, 65 hp 73-76 Cross Flow W/Boost Port High Dome not available Can Use Part No. 100-15 Low Dome N/A  200-15 
60 hp 91-97  100-07K  200-07 
65 hp 73-76 Cross Flow W/Boost Port Low Dome  100-15K  200-15 
70 hp 77-83 Cross Flow W/Boost Port Low Dome  100-15K  200-15
70 hp 87-89 Loop Charge with Boost Port bottom guided 100-25K  200-25 
75 hp 84-86 Cross Flow W/Boost Port High Dome not available
Can Use Part No. 100-15 Low Dome
N/A  200-15 
75 hp 90-91 Loop Charge W/Boost Port 100-25K  200-25 
75 hp 92-93 Loop Charge Top Guided 100-35K  200-25 
75 hp 94-04 Inline 3 Loop Charge Top Guided  100-40K  200-20 
Mercury 1.5 Liter OptiMax  100-27K  200-27 
80 hp 87-89 Loop Charge W/Boost Port 100-25K  200-25 
80 hp 78-83 Cross Flow W/Boost Port High Dome not available
Can Use Part No. 100-15 Low Dome 
N/A  200-15 
85 hp 73-77 Cross Flow W/Boost Port High Dome not available
Can Use Part No. 100-15 Low Dome
N/A  200-15 
90 hp 87-91 Loop Charge W/Boost Port  100-25K  200-25 
90 hp 92-93 Loop Charge Top Guided 100-35K  200-25 
90 hp 94-00 Inline 3 Loop Charge 100-40K  200-20 
90 hp 1.5L OptiMax  100-27K  200-27 
100 hp 89-91 Inline 4 Loop Charge W/Boost Port Bottom Guided 100-25K  200-25 
100 hp 92-93 Inline 4 Loop Charge Top Guided  100-35K  200-25 
100 hp 94-01 Inline 4 Loop Charge 100-40K  200-20 
115 hp 92-93 Inline 4 Loop Charge Top Guided  100-35K  200-25 
115 hp 94-04 Inline 4 Loop Charge 100-40K  200-20
115 hp 89-91 Inline 4 Loop Charge W/Boost Port Bottom Guided   100-25K  200-25
115 hp 70-83 Inline 6 Cross Flow High Dome Not Available
Can Use Part No. 100-15 Low Dome 
N/A  200-15 
115 hp 84-88 Inline 6 Cross Flow Low Dome  100-15K  200-15 
115 hp 1.5L Optimax 100-27K  200-27 
115 hp 2.5L Optimax  100-28PK  200-28 
125 hp 94-00 Inline 4 Loop Chagre  100-40K  200-20 
135 hp 70-71 Inline 6 Cross Flow High Dome Not Available
Can Use Part No. 100-15 Low Dome 
N/A  200-15 
135 hp 2.0 Liter 81-91 W/Boost Port Bottom Guided Used With Connecting
Rod #636
100-50PK  200-30 
135 hp 2.0 Liter 92-00 W/Boost Port Top Guided Used With Connecting
Rod #644
100-30PK 200-30 
135 hp 2.5L OptiMax OG590000-OG96499 Used With Connecting
Rod #644
100-28PK  200-28 
140 hp 72 Inline 6 Cross Flow High Dome Not Available
Use 100-15 Low Dome 
N/A  200-15 
140 hp 78-81 Inline 6 Cross Flow W/Boost Port Low Dome 100-15K  200-15
150 hp 73-78 Inline 6 Cross Flow W/Boost Port Low Dome 100-15K  200-15
150 hp 79-91 2.0 Liter W/Boost Port Bottom Guided Used With Connecting
Rod #636
100-50PK  200-30 
2.0 Liter W/Boost Port Top Guided Used With Connecting
Rod #644
100-30SK  200-30 
150 hp 2.5L Bottom Guided Used With Connecting
Rod #636
100-19PK  200-19 
150 hp 2.5L XR-6 92-97 and  EFI 93-99 Top Guided Used With Connecting
Rod #644
100-20PK  200-20 
150 hp 2.5L OptiMax OG960500-OT178499 Top Guided Used With Connecting
Rod #644 
100-28PK  200-28 
175 hp 76-81 2.0 Liter Loop Charge W/Boost Port Bottom Guided
Used With Connecting Rod #636
100-50PK  200-30 
175 hp 78-91 2.4 Liter Chrome Block  100-10PCHK  200-10CH 
175 hp 78-91 2.4 Liter Cast Iron Resleeve  100-10PK  200-10 
175 hp 92-00 2.5 Liter, Off shore EFI XR1, XR2 Magnum Top Guided Used With Connecting Rod #644 100-20PK  200-20 
Big Pin DFI 2.5 Liter OT178500-Up Used With Connecting Rod #600  100-49PK  200-49 
200 hp 78-90 2.4 Liter Chrome Block  100-10PCHK  200-10CH 
200 hp 78-90  2.4 Liter Cast Iron Resleeve Loop Charge W/Finger Ports  100-10PK  200-10 
200 hp 2.5 Liter Bottom Guided Used With Connecting Rod #636 100-19PK  200-19 
200 hp 92-00 2.5 Liter XR-1, EFI, Off shore Top Guided Used With Connecting
Rod #644
100-20PK  200-20 
150-175 hp 2.5 Liter DFI OT178500-Up Used With Connecting Rod #600 100-49PK  200-49 
WSM High Perfomance Piston Mercury 3.5" Top Guided 2.5 Liter With 1,5mm Rings
for use with 644Rod
100-21PK  200-19 
200 hp 3.0L OptiMax OT599000-Up Oval Pocket on Top of Piston 100-47PK  200-27 
200 hp 3.0L OptiMax 2000-04 Round Pocket on TTop of Piston  100-48PK  200-48 
225 hp 80-81 2.4 Liter Chrome Block 100-10PCHK  200-10CH 
225 hp 80-81 2.4 Liter Cast Iron Resleeve Loop Charge  100-10PK  200-10 
225 hp 3.0L OptiMax 98-04 Round Pocket On Top of Piston  100-48PK  200-48 
3.0 Liter 94-99 Carbureted and EFI 100-45PK  200-45 
250 hp 3.0L OptiMax Oval Pocket On Top of Piston  100-47PK  200-27 
250XB, 300X 3.0 Liter EFI OG980600 OT800999  100-45PK  200-45