Distributor Cap Corrosion and RPM Gauge not working

[B-Reynolds]

Recent purchase 1999 Mercruiser 3.0. Attempting to track down issues with issues getting on plane. Engine idles and starts fine but low power when attempting to get on plane.
the RPM gauge is not working, while looking around and cleaning terminals I noticed corrosion on the distributor cap. Is this something that would cause low power under load? Can it be cleaned? Does the whole distributor or just the cap need replacing?
see photos.

 

[B-Reynolds]

 

[Maclin]

Just cap and rotor, I bet the distributor itself is ok. I would get new sparkplugs also. That should make a difference.

 

[achris]

When chasing down these sorts of problems, I have a 'standard checklist'....

Standard troubleshooting for an engine.

Engines require certain things to operate properly... Basically they need the correct fuel/air mixture to be compressed and then fired at the right time.

So, in this order.

1. Compression tests.
2. Check spark plugs, replace if needed.
3. If points, replace, along with condenser and rotor. Check and adjust, if needed, points cam dwell angle.
4. Inspect distributor cap, rotor and leads, replace if necessary.
5. Check spark quality (needs to be a nice BLUE spark drawn over 1/2").
6. Set timing. Check timing advance is working correctly.

When all of these items have been done, THEN move to the fuel system....

7. Check/change fuel filters and check that the fuel system is not sucking air.
8. Check fuel pump pressure.
9. Check for full opening of the carb. Also ensure choke is opening fully when the engine is warm.

Chris.........