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Okay...
So I have:
2003 Ultra 150
Bore Gauge
Micrometers (3")
Factory Service Manual
Here is whats going on... This is a newer boat for me. I bought the boat with a terrible, rebuild job done to it. I ripped the motor down because I thought I was hearing some slap. Sure enough slap was there. One of my pistons had .013 clearance to cylinder. It was surely the culprit. Interestingly enough, the cylinder with the slap has a different stamping near the head. Two of the cylinders have a "B" stamp whereas the one that was looser had a "C" stamp. Dunno if the stamping makes a difference, but it was bigger than the "B" Cyls. So I got a Nikasiled "B" cylinder to match the others. Now are the cylinders are the same. So now... I got the book, some tools, and some parts.
My pistons read 3.141
FSM says:
Piston Diameter
Standard: 79.865 ∼ 79.880 mm
(3.14429 ∼ 3.14488 in.)
Service Limit: 79.72 mm (3.1386 in.)
○If the measurement is less than the service limit, replace
the piston.
Fair enough... but the pistons look super clean, yet still bigger than the service limit
My cylinders read 3.150 on the nose
FSM says:
Cylinder Inside Diameter
Standard: 80.000 ∼ 80.015 mm (3.14961 ∼ 3.15019
in.) and less than 0.01 mm difference
between any two measurements
Service Limit: 80.10 mm (3.1535 in.), or more than
0.05 mm (0.0020 in.) difference
between any two measurements
So it appears my Cylinders are good, Pistons??? dunno. This puts my Cyl to Piston clearance at .009 in.
FSM says:
Piston/Cylinder Clearance
0.130 ∼ 0.140 mm (0.005118 ∼ 0.005512 in.)
What to do? The pistons look so new, but I have no way to get to the .005 number. I think my cylinders are so close to stock that I don't need to worry about replating. Anyone have any advice?
Thanks,
Jason
So I have:
2003 Ultra 150
Bore Gauge
Micrometers (3")
Factory Service Manual
Here is whats going on... This is a newer boat for me. I bought the boat with a terrible, rebuild job done to it. I ripped the motor down because I thought I was hearing some slap. Sure enough slap was there. One of my pistons had .013 clearance to cylinder. It was surely the culprit. Interestingly enough, the cylinder with the slap has a different stamping near the head. Two of the cylinders have a "B" stamp whereas the one that was looser had a "C" stamp. Dunno if the stamping makes a difference, but it was bigger than the "B" Cyls. So I got a Nikasiled "B" cylinder to match the others. Now are the cylinders are the same. So now... I got the book, some tools, and some parts.
My pistons read 3.141
FSM says:
Piston Diameter
Standard: 79.865 ∼ 79.880 mm
(3.14429 ∼ 3.14488 in.)
Service Limit: 79.72 mm (3.1386 in.)
○If the measurement is less than the service limit, replace
the piston.
Fair enough... but the pistons look super clean, yet still bigger than the service limit
My cylinders read 3.150 on the nose
FSM says:
Cylinder Inside Diameter
Standard: 80.000 ∼ 80.015 mm (3.14961 ∼ 3.15019
in.) and less than 0.01 mm difference
between any two measurements
Service Limit: 80.10 mm (3.1535 in.), or more than
0.05 mm (0.0020 in.) difference
between any two measurements
So it appears my Cylinders are good, Pistons??? dunno. This puts my Cyl to Piston clearance at .009 in.
FSM says:
Piston/Cylinder Clearance
0.130 ∼ 0.140 mm (0.005118 ∼ 0.005512 in.)
What to do? The pistons look so new, but I have no way to get to the .005 number. I think my cylinders are so close to stock that I don't need to worry about replating. Anyone have any advice?
Thanks,
Jason
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