1964 Johnson 60 Horse Outboard.
A lot of new parts, but hoping to receive some ideas on the next troubleshooting steps:
The engine fires up quite easily, runs well. After getting out of the water, all plugs are burning clean; no carbon buildup. Boat planes out well, gets to top speed. Once the engine warms up, I lose a couple MPH. It will run like this for awhile, until later in the day, I can barely plow up river. What might cause this gradual decrease in power over the course of the day?
New plugs, new wires, magneto rebuild, new reeds, carb rebuilt, new fuel filter, new head gaskets, new primer bulb, .
Troubleshooting thus far: Ran engine in bucket up to operating temperature. Sprayed starting fluid around carb, intake, and heads, looking for an air leak. Didn't find anything. Compression test while hot. I have low compression in Cylinder one (top portside), but it's only down about 8 pounds. The compression reading doesn't change whether hot or cold (I was expecting a huge drop in compression once hot). Also ran on two different tanks with the same results. Couple of cans of Seafoam ran through. Pulled plugs for examination. All look to be burning perfectly (no buildup).
If you were me, what would be your next step (don't say "buy a new engine" :-D )?
A lot of new parts, but hoping to receive some ideas on the next troubleshooting steps:
The engine fires up quite easily, runs well. After getting out of the water, all plugs are burning clean; no carbon buildup. Boat planes out well, gets to top speed. Once the engine warms up, I lose a couple MPH. It will run like this for awhile, until later in the day, I can barely plow up river. What might cause this gradual decrease in power over the course of the day?
New plugs, new wires, magneto rebuild, new reeds, carb rebuilt, new fuel filter, new head gaskets, new primer bulb, .
Troubleshooting thus far: Ran engine in bucket up to operating temperature. Sprayed starting fluid around carb, intake, and heads, looking for an air leak. Didn't find anything. Compression test while hot. I have low compression in Cylinder one (top portside), but it's only down about 8 pounds. The compression reading doesn't change whether hot or cold (I was expecting a huge drop in compression once hot). Also ran on two different tanks with the same results. Couple of cans of Seafoam ran through. Pulled plugs for examination. All look to be burning perfectly (no buildup).
If you were me, what would be your next step (don't say "buy a new engine" :-D )?