Took my boat out yesterday and had no power with WOT. I drove around in circles for 5 minutes at low speed with what seemed like normal forward speed. When I tired to open it up RPMs would increase but boat would slow down. If I turned the boat I would lose all forward momentum and the boat would barely move. Took the boat back home and went to get a compression gauge. Both cylinders are 60PSI even on pretty much a cold engine. I added a few CCs of oil to each of the cylinders and tested again. The top cylinder increased by 2-5 psi but the lower saw no improvement. Tested the spark plugs with an inline tester and they were fine. Decided to pull the cylinder head. First the bolts removed every easily. It took little to no force with a small 1/4 socket wrench to remove the bolts. I would have expected more force was needed to “break the seal.” Once the bolts were out it took no force at all to remove the cylinder head. Simply a gentle push from my hand and off it came. The gasket removed very easily as well. Almost as it it was not sealed. The cylinders themselves look great. No scoring that I can see or feel. They are smooth. The pistons have carbon buildup but I have a can of seafoam to treat. So I am curious if my problem stems from an improperly torqued down cylinder head or if I should be looking for more. New gasket will be here tomorrow. Don’t want to install before considering other causes. I appreciate any response I get.
More back story if you want to read:
Bought the boat two weeks ago. Owner said it sat for the past year. He had replaced the fuel tank(red plastic) and the fuel line/bulb to the engine. Started up on first pull and had great water flow in a bucket. Took boat out next day and it ran fine for 15minutes. WOT if I had to guess we were going around 20mph. However, after 15 minutes engine died. Sputtered down then just died. Took it home. Checked impeller. It was fine. Looks brand new. Fins are straight when removed and absolutely no wear marks on it. So I returned it to its place for now.
Then looked at the ignition system. Ended up just replacing everything. One spark plug wire had no resistance when tested and the other was shorted. In all the motor has new condensers, points coils, and spark plug cables. Old owner said spark plugs were replaced last year. They look in good shape but still tried to replace them. However, the spark plugs listed in this site were incorrect. They are too long when inserted into the block. So attempting to find the correct champion plugs.
Replaced all of this to find the armature plate was loose. Did the 12,3,6,9 notching on the retaining ring and the engine finally started back up. Ran it for 30 minutes in a bucket then Decided to take it back out. So that was yesterday.
CArb was also broken down 2 times and cleaned. It looks to have been rebuilt recently but I have bought a rebuild kit and plan to rebuild it tomorrow.
More back story if you want to read:
Bought the boat two weeks ago. Owner said it sat for the past year. He had replaced the fuel tank(red plastic) and the fuel line/bulb to the engine. Started up on first pull and had great water flow in a bucket. Took boat out next day and it ran fine for 15minutes. WOT if I had to guess we were going around 20mph. However, after 15 minutes engine died. Sputtered down then just died. Took it home. Checked impeller. It was fine. Looks brand new. Fins are straight when removed and absolutely no wear marks on it. So I returned it to its place for now.
Then looked at the ignition system. Ended up just replacing everything. One spark plug wire had no resistance when tested and the other was shorted. In all the motor has new condensers, points coils, and spark plug cables. Old owner said spark plugs were replaced last year. They look in good shape but still tried to replace them. However, the spark plugs listed in this site were incorrect. They are too long when inserted into the block. So attempting to find the correct champion plugs.
Replaced all of this to find the armature plate was loose. Did the 12,3,6,9 notching on the retaining ring and the engine finally started back up. Ran it for 30 minutes in a bucket then Decided to take it back out. So that was yesterday.
CArb was also broken down 2 times and cleaned. It looks to have been rebuilt recently but I have bought a rebuild kit and plan to rebuild it tomorrow.