18.5 hp intek ohv valve adjustment???
- Thread starter willie 76
- Start date
Ok, let's start over. There are four main causes for this problem. One, bad battery or bad ground. Here you should check that the battery is good and both the battery ground and the starter ground are clean and tight on the chassis or engine. Two, valve clearances are accurate. Three, compression release is working properly. Four, bad starter.
You say that you have made sure that numbers one and two are good, so let's look at number three. Need you to remove the spark plug and valve cover. While sitting in front of the engine, turn the flywheel by hand and watch the valves opening and closing. You should see them in this order. Intake valve opens then closes, both valves close, exhaust valve opens slightly then closes, both valves stay closed until the exhaust valve opens. At the end of one cycle you will see the intake valve open while the exhaust valve is still open (this is the valve overlap) to start a new cycle. With the spark plug out you should be able to turn the flywheel very easily. If you do not see the exhaust valve open slightly at the end of the compression stroke, retest your valve clearances.
PS: if you need a procedure to set the valve clearances let me know.
You say that you have made sure that numbers one and two are good, so let's look at number three. Need you to remove the spark plug and valve cover. While sitting in front of the engine, turn the flywheel by hand and watch the valves opening and closing. You should see them in this order. Intake valve opens then closes, both valves close, exhaust valve opens slightly then closes, both valves stay closed until the exhaust valve opens. At the end of one cycle you will see the intake valve open while the exhaust valve is still open (this is the valve overlap) to start a new cycle. With the spark plug out you should be able to turn the flywheel very easily. If you do not see the exhaust valve open slightly at the end of the compression stroke, retest your valve clearances.
PS: if you need a procedure to set the valve clearances let me know.
Carscw
Lawn Pro
- Joined
- Aug 11, 2011
- Threads
- 66
- Messages
- 6,375
Adjusting valves is confusion for someone that has never done it. Here is a easy way.
Take spark plugs out. Take valve cover off.
Turn flywheel counterclockwise till one valve is open all the way. ( valve pushed in)
Adjust the other one to specks. Repeat for the other valve.
Take spark plugs out. Take valve cover off.
Turn flywheel counterclockwise till one valve is open all the way. ( valve pushed in)
Adjust the other one to specks. Repeat for the other valve.
Rivets,
With the spark plug out and the valve cover off, this is what I see:
Intake opens
intake closes
after about 3/4 turn of the flywheel, exhaust opens
exhaust closes
lather, rinse, repeat.
There was no in-between, valves slightly open, or valves open at the same time. And just in case it might mean something to you, the first time the exhaust valve was opening, a bunch of gas came out of the spark plug hole.
Electrical speak is not my native tounge, but the battery is brand new, i've recharged it to make sure it was at 100%. I have 2 cables to the battery a red and a black (positive and negative) I didn't see a green ground wire. The starter has one red wire going to it. All are clean and tight. I am assuming (which I am loathe to do) that the starter is good because with the spark plug out, it spins the flywheel free and easy.
With the spark plug out and the valve cover off, this is what I see:
Intake opens
intake closes
after about 3/4 turn of the flywheel, exhaust opens
exhaust closes
lather, rinse, repeat.
There was no in-between, valves slightly open, or valves open at the same time. And just in case it might mean something to you, the first time the exhaust valve was opening, a bunch of gas came out of the spark plug hole.
Electrical speak is not my native tounge, but the battery is brand new, i've recharged it to make sure it was at 100%. I have 2 cables to the battery a red and a black (positive and negative) I didn't see a green ground wire. The starter has one red wire going to it. All are clean and tight. I am assuming (which I am loathe to do) that the starter is good because with the spark plug out, it spins the flywheel free and easy.
How many revolutions of the flywheel does it take to repeat the cycle? I can understand if you do not see the slight exhaust valve opening between the compression and power stroke, but I you don't see both valves open for a very short time between the exhaust and intake strokes, I feel you have a major internal problem. Second, why are you looking for a green wire on the battery ground? Green grounds are only used on AC systems. Finally, you can never assume anything when troubleshooting electrical circuits.