Re: 1989 force 150 quirks
Compression and engine resistance are higher during a warm start than a cold start. Therefore, your starter motor has just enough power to crank over the engine adequately at cold start. What can cause this? Low voltage to the starter or a bad starter.
Let's start with voltage. Did you check the battery? It should read a minimum of 9 volts while cranking. More is better. A marginal one could cause this. Re-check the cables at their connections--both ends. Be sure there is no corrosion or high resistance at the connections. When you tilt the engine you shift the cables. If you have a marginal connection, the shifting might break through corrosion and make it better. Bypass the start solenoid by hand for a hot start with a very heavy wire. Wear heavy gloves. There will be heat and sparks. A light wire will heat and melt. If the internal contacts are pitted or carboned, then there is a high restance. If everything is fine when you bypass it, then that's your problem.
Finally, you may have worn brushes in the starter motor itself. It's an easy disassembly to check them. They need to be longer than 1/2 inch. You may have bad windings on the armature of the motor. When you disassemble, look for burned insulation. Also check the commutator for deposits. It should be clean and a bright copper color. The spaces between segments should not be filled in with carbon and junk and no segments should be missing.
Notice the logic I have used in going from easiest to most complex. Occams Razor: The simplest solution is usually the correct one.
BTW The hard starting when turning over slow is a function of the slow cranking speed. That electronic ignition produces a weaker spark at slower speeds--just when you need a strong spark. Always carry an extra set of clean plugs. When the old ones foul, these engines can be a bear to start and it's easier to replace the plugs than to fight with it. But if your battery fails, they can be rope started. It is not that difficult to pull them over.
