Hi, first post here. I've been searching and reading a lot but looking for some advice. I have a 1988 88 HP Evinrude on a boat that I've had for about two years. I've had a hard start/rough idle problem for some time now. The engine performs well at WOT, but it takes some cranking to get it to start and will not idle well.
I've verified the timing pointer, the carb plates are in sync, and set the cam follower pickup. There seems to be a lot of play in the throttle cable linkage, as well as the spark advance rod where it connects to thing under the flywheel. There also seems to be a lot of play in the throttle lever. All this play makes my timing readings not precise when checking the cam follower pickup timing. I ordered a new bushing kit for the spark advance rod, so that may help. When checking the cam follower pickup timing, I can get it as low as about 6 degrees before the engine will stall. More advance keeps the engine running. The idle adjustment screw has to be fully in to offer enough ignition advance for the engine to idle.
I did not check the max spark advance timing but will try soon, but not sure it will help this problem. The spark advance rod on the 1988 does not have a thumbwheel but rather 3 positions on the retainer that attaches to the throttle lever.
Plug 1 looked pretty fouled when I pulled it to check TDC today. I'm running the Champion plugs recommended for the engine.
I replaced the water/fuel filter and it didn't seem to help. I always run ethanol free 93 octane, premixed with OMC oil at 50:1.
With the front plate off, I stuck my hand (with a latex glove on) over each of the two inlets. It seemed like the top was creating more vacuum than the bottom, so much so that I wonder if it is even running on all four cylinders.
Admittedly, I'm a novice to outboard engines but I am very familiar around a car engine. I could really use some guidance as to what to do next. Compression test? Decarb? Plugs? I got a factory service manual in the mail today and will continue to read through it. Any help is appreciated. Thanks!
I've verified the timing pointer, the carb plates are in sync, and set the cam follower pickup. There seems to be a lot of play in the throttle cable linkage, as well as the spark advance rod where it connects to thing under the flywheel. There also seems to be a lot of play in the throttle lever. All this play makes my timing readings not precise when checking the cam follower pickup timing. I ordered a new bushing kit for the spark advance rod, so that may help. When checking the cam follower pickup timing, I can get it as low as about 6 degrees before the engine will stall. More advance keeps the engine running. The idle adjustment screw has to be fully in to offer enough ignition advance for the engine to idle.
I did not check the max spark advance timing but will try soon, but not sure it will help this problem. The spark advance rod on the 1988 does not have a thumbwheel but rather 3 positions on the retainer that attaches to the throttle lever.
Plug 1 looked pretty fouled when I pulled it to check TDC today. I'm running the Champion plugs recommended for the engine.
I replaced the water/fuel filter and it didn't seem to help. I always run ethanol free 93 octane, premixed with OMC oil at 50:1.
With the front plate off, I stuck my hand (with a latex glove on) over each of the two inlets. It seemed like the top was creating more vacuum than the bottom, so much so that I wonder if it is even running on all four cylinders.
Admittedly, I'm a novice to outboard engines but I am very familiar around a car engine. I could really use some guidance as to what to do next. Compression test? Decarb? Plugs? I got a factory service manual in the mail today and will continue to read through it. Any help is appreciated. Thanks!