Fishing V6 piston clearance 2.0 vs 2.5

**RoyE** · 01-21-2022, 06:20 AM

I'm looking at the specs in my manual for Mercury V6 135 150 175 200 225 (1992 up)

105 Jet/135/150 (2.0 liter):
Cylinder bore: 3.125"
Piston: 3.115 +/- 0.002"

Thus clearance is 0.008" - 0.012"

XR6/MAGIII/175/200 etc (2.5 liter):
Cylinder bore: 3.501"
Piston: 3.494 +/- 0.001"

Thus clearance is 0.006" - 0.008"

Why is the piston clearance so much higher on the 2 liters? Anyone can explain?

**rock** · 01-21-2022, 08:45 AM

Maybe sleeve thickness.

Rock

**OnPad** · 01-21-2022, 06:58 PM

That's weird, you would think it would be the other way around by .001 or .002
12 thousandths would be pretty sloppy. 2.0 may be a good motor to run forged pistons in. Although I do have one that squeaked a piston out in the shop. I think someone ran it out oil or water though.

**SJD1974** · 01-31-2023, 01:18 PM

I have a clearance of . 01 to . 012 on my 88 2.0 black Max is that acceptable. I'm going to hone and ring it.
They are Wiseco pistons.
Is that too much?

**SJD1974** · 01-31-2023, 04:55 PM

Originally Posted by SJD1974

I have a clearance of . 01 to . 012 on my 88 2.0 black Max is that acceptable. I'm going to hone and ring it.
They are Wiseco pistons.
Is that too much?

I made a mistake I measured at the top of the piston and not at the ristpin height.
Im at. 007