Piston Rings, Play Between The Slots (Mm); Piston Rings, Assembly Order; Piston - Refitting; Clearance - Kohler KD225 Workshop Manual

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DISASSEMBLY/REASSEMBLY
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KD 225_315_350_400_440 Workshop Manual_cod. ED0053029330_1° ed_ rev. 00

Piston rings, play between the slots (mm)

225
A 0 0 . 7 ÷ 0 1 . 1 5
B 0 0 . 4 ÷ 0 0 . 8
C 0 0 . 3 ÷ 0 0 . 7 0
Replace the piston or piston rings if the value exceeds the maximum
limit.

Piston rings, assembly order

A = 1st Chromium plated piston ring (nitrided for 225-350-400)
B = 2nd piston ring (torsional)
C = 3rd piston ring (oil scraper) (nitrided for 225-350-400)
D = Chromium plated zone
Note: If a word (top, or some other word) is written on the surface of
a piston ring, mount that surface upwards.
Before inserting the piston into the cylinder, oil and turn the pi-
ston rings so that the cuts are staggered 120° to each other.
In KD 350 and KD 225 engines, the second piston ring is not
torsional, while the first and third piston rings do not have chro-
mium plated zones but are nitrided.
Lubricate the following parts with oil before mounting: the pi-
ston pin, the piston, the cylinder and the big-end bearing

Piston - Refitting

Connect piston to connecting rod, lubricate piston pin and introduce
it into the piston/connecting rod assembly by exerting pressure with
your thumb.
Fit both piston pin circlips and check that they are well seated.
When introducing both the connecting rod and the piston into the
cylinder make sure that the larger crown surface A (if compared to the
combustion chamber) is on the same side as the pushrod opening B.

Clearance

A = Clearance
C = Head gasket
The thickness of gasket C determines the clearance A, which must be
0.45-0.55 mm for KD 315 with injection pump serial N° 6590-259; it is
0.50-0.60 mm with injection pump serial N° 6590-281.
The clearance is 0.45-0.55 mm for KD 225 in all cases.
The clearance is 0.50-0.60 mm for KD 350-400-440 in all cases.
For the correct thickness of gasket C see table in fig. 49÷50.
There are gaskets with inner diameters oversized by 1 mm for KD
315 and KD 350, required if the cylinders are ground.
315 350-400
0 0 . 7 ÷ 0 1 . 0 0 0 . 3 5 ÷ 0 1 . 1
0 0 . 5 ÷ 0 0 . 8 0 0 . 5 0 ÷ 0 0 . 9
0 . 4 ÷ 0 0 . 7 5 0 0 . 3 0 ÷ 0 0 . 8 7
440
0 0 , 7 ÷ 0 1 , 1
0 0 , 5 ÷ 0 0 , 9
0 0 , 3 ÷ 0 0 , 7