1993 Yamaha golf cart Ser# JF2302993, J38 285 ... 1) Piston Clearance ? 2) Valve lash clearance or adjustment ? 3) View of timing marks ? Thank you...

A sure sign that it's time for a valve lash adjustment is if your engine is making a loud clicking or tapping noise when starting up or if you experience a loss in engine power. You can find more details on the suggested adjustment frequency here.
https://www.allstatepeterbilt.com/blog/valve-adjustments-explained

How To Check Tappet Clearance

1. Taking all safety precautions.
2. Make sure the piston is on TDC. ...
3. Make sure the engine has cooled down.
4. Loosen the lock nut of the rocker arm.
5. Now adjust the tappet clearance between the rocker arm & valve stem by tightening or loosing the nut below the lock nut.

https://www.marinesite.info/2012/02/1why-tappet-clearances-is-given-and-how.html

To adjust the valve clearances, use a spanner or a socket wrench on the crankshaft-pulley bolt. Turn the engine in its normal direction of rotation until No. 1 piston is at the top dead centre ( TDC ) of the compression stroke .
https://www.howacarworks.com/engine/checking-and-adjusting-valves

MEASURE AND ADJUST VALVE CLEARANCE 1. Turn the flywheel clockwise until the intake valve opens and then closes. Continue turning flywheel until the TDC (top-dead-center) mark (A) on the flywheel is upward. Both valves (B) must be closed and the piston (C) must be at the top of its compression stroke. If the valves are open, the piston is on the exhaust stroke and the flywheel must be turned one revolution
2. Measure valve clearance using a feeler gauge. VALVE CLEARANCE SPECIFICATION Item Specification Intake Valve (A) . . . . . . . . . . . . . . . . . . . . . . . 0.13 mm (0.005 in.) Exhaust Valve (B) . . . . . . . . . . . . . . . . . . . . . . 0.33 mm (0.013 in.)
3. If necessary, hold tappet and turn tappet screw to adjust valve clearance
Below you will find a complete manual with illustrations to complete rebuild, ***PRESS THE HELPFUL BUTTON****
http://www.wfmfiles.com/download/manuals/CTM2_-_16_18_20_24_HP_Onan_Engines.pdf

ADJUSTING THE VALVE CLEARANCE
Remove:
engine cooling fan
Remove:
timing plug
Check:
valve clearance Out of specification
Adjust.
Valve clearance (Cold)
Intake-0.10~0.15 mm
(0.0039~0.0059 in)
Exhaust -0.15~0.20 mm
(0.0059 ~0.0079 in)

a.Turn the crankshaft counterclockwise with awrench.b.Align the
" I"
mark on the rotor with the stationary pointer
on the A.C. magneto cover. When the

" I "

mark is aligned with the stationary pointer, the piston is at the Top Dead Center (T D C).
NOTE:
•
When the piston is at the Top Dead Center(TDC) on the compression stroke, thereshould be clearance between the valve stemtips and their respective rocker arm adjustingscrews.
•
If there is no clearance, rotate the crankshaftcounterclockwise one turn.c.Measure the valve clearance using a thickness gauge

turn the crank shaft and watch the relationship between the piston position and the cam followers. As the piston nears top dead centre you will see the exhaust cam follower start to move down and the inlet cam follower start to rise up. This will create a rocking motion of the cam followers at top dead centre. This is known as valve overlap assemble the motor in this position. Ensure the valve clearance is backed right off Turn the crank shaft one full revolution and you now have the compression stroke . This places the piston again on TDC and it is at this position you adjust the valve clearance. Check that clearance for the tappets as most engines run .010" and .012"tappet clearance. If the head is fitted last place the push rods in the cam followers if you cannot see the cam followers and it does the same job. When the top of the push rods reach the overlap situation it is just an extension of the cam followers.

Cummins M11

Intake valve clearance 0.010 inch
Exhaust valve clearance 0.024 inch

The firing order is 1-5-3-6-2-4 and that is the order the valves should be adjusted started with first timing mark on main pulley adjust cylinder number 1 The valves and injector should be adjusted at the same time The crankshaft is then rotated 120 degrees to next timing mark and cylinder 5 is adjusted, the crank is rotated again 120 degrees to next timing mark and cylinder 3 is adjusted.then back to the first timing mark, cylinder 6 is adjusted, etc/

Adjusting nut on plunger should be adjusted to the point where you feel the plunger just reaches the bottom.of travel/bottoms out.

Hi bbg713,
I hope I can help you out. The valve lash (tappet clearance) on engines of approx this size should be 0.005-0.007 inches (0.13-0.18 mm) for intake valve and 0.007-0.009 inch 0.18-0.23 mm for exhaust valve (cold engine). Adjust tappet clearance by grinding end of valve stem to increase clearance or grind valve seat deeper to decrease clearance. I hope I have helped you a bit. Any more questions are welcome. Regards and good luck. Denis.

Depends on which engine you have. If you have

ADJUSTMENT Although it is sometimes possible to reuse an old cylinder head cover gasket, in most cases it makes more sense to purchase a new one before beginning the procedure. Some vehicles may require the use of silicone sealant either with or without a new cover gasket. For more details, please refer to the cylinder head cover procedures in Engine & Engine Overhaul of this repair guide and refer to the gasket manufacturer's instructions.

Z24i Engine
See Figures 1, 2 and 3
For the intake valves: 1-4-5-8 valve clearance is 0.012 in. (0.30mm). For the exhaust valves: 2-3-6-7 valve clearance is 0.012 in. (0.30mm). The pivot locknut torque specification is 12-16 ft. lbs. (16-22 Nm).

1. The valves must be adjusted with the engine warm, so start the truck and run the engine until the needle on the temperature gauge reaches the middle setting. After the engine is warm, shut it off.
2. Note the location of any wires and hoses which may interfere with cylinder head cover removal, disconnect them and move them to one side. Remove the bolts holding the cylinder head cover in place and remove the cover. Remember, the engine will be hot, so be careful!

Fig. Fig. 1: Check the valve clearance with a flat feeler gauge-Z24i engine

Fig. Fig. 2: Loosen the locknut and turn the adjusting screw to adjust the valve clearance-Z24i engine

Fig. Fig. 3: With the No. 1 piston at TDC, adjust the top set of valves FIRST; with the No. 4 piston at TDC, adjust the bottom set of valves SECOND-Z24i engine

1. Rotate the crankshaft until the timing marks indicate that the No. 1 piston is at TDC of the compression stroke. If you're not sure of which stroke you're on, remove the No. 1 spark plug and hold your thumb over the hole. Pressure will be felt as the piston starts up on the compression stroke.
2. Refer to the accompanying illustration (upper part), then check valves (1), (2), (4) and (6) using a flat bladed feeler gauge. The feeler gauge should pass between the valve stem end and the rocker arm screw with a very slight drag. Insert the feeler gauge straight, not at an angle.
3. If the clearance is not within the specified value, loosen the rocker arm lock nut and turn the rocker arm screw to obtain the proper clearance. After correct clearance is obtained, tighten the locknut.
4. Rotate the crankshaft until the timing marks indicate that the No. 4 piston is at TDC of the compression stroke. If you're not sure of which stroke you're on, remove the No. 4 spark plug and hold your thumb over the hole. Pressure will be felt as the piston starts up on the compression stroke.
5. See the illustration (lower part), then check valves (3), (5), (7) and (8). Check and adjust valve clearance as necessary.
6. Install the cylinder head cover gasket, the cover itself and any wires or hoses which were removed. Check the engine oil level.

KA24E, VG30i and VG30E Engines
See Figures 4 and 5
These models utilize hydraulic valve lifters. Periodic adjustment is neither necessary or possible. There is however a bleed down procedure that is necessary when the valve train has been disassembled.
HYDRAULIC LIFTER BLEED DOWN

1. Remove the cylinder head cover.
2. Check the lifters for proper operation by pushing hard on each lifter with fingertip pressure.
3. If the valve lifter moves more than 0.04 in. (1mm), air may be inside it. Make sure the rocker arm is not on the cam lobe when making this check.
4. Install the cylinder head cover.
5. If there was air in the lifters, bleed the air by running the engine at 1000 rpm for 10 minutes.

Fig. Fig. 4: Cross-sectional view of an installed hydraulic valve lifter-4 cylinder engine

Fig. Fig. 5: Cross-sectional view of an installed hydraulic valve lifter-6 cylinder engine

Valve Lash ADJUSTMENT 1.6L Engines NOTE: Measure valve clearance with the engine cold.

1. Before servicing the vehicle, refer to the precautions in the beginning of this section.
2. Remove the valve cover.
3. Set the engine to Top Dead Center (TDC) of the compression stroke for the cylinder to be adjusted.
4. Check the valve clearance. The valve clearance specifications are as follows:
   • Intake valves: 0.005-0.007 inches (0.13-0.17mm)
   • Exhaust valves: 0.005-0.007 inches (0.13-0.17mm)
5. After adjustment, tighten the locknuts to 11-14 ft. lbs. (15-19 Nm).
6. Repeat for each valve to be adjusted.

1.8L, 2.0L and 2.5L Engines The 1.8L, 2.0L and 2.5L engines utilize automatic hydraulic lash adjusters to maintain proper valve lash at all times. Periodic valve lash inspection and adjustment is not necessary or possible.

did u hav piston @tdc power stroke-valves shud slightly clic with ur hand after ajust-mite hav performed it at exhaust stroke! let me know

Sounds like you need to adjust the valves.