Outboard Yamaha 5 BS (2/3)
13.06.2019 Sonne 27°C 10 kt SW
After the winter break we returned to the problem again.
First, disconnect and disassemble the fuel pump, which is bolted to the engine and working with negative pressure, and look at the diaphragms. Diaphragms and gaskets as far as OK only parts of the protruding gasket have dissolved and are in the gasoline pump. Some paper seals are also broken. Clean the fuel pump and replace the paper gaskets and then reassemble everything.
New attempt to start but not start.
Now for the ignition system:
Initial tests showed no spark or only a weak one in the ignition system. So remove spark plug and look, unscrew ignition coil and measure by ignition coil. By measuring the ignition coil was ok with the values, primary side 0.5 ohms secondary 5 kilohms, including plug. Then put everything together again and test - and no spark.
Next, disconnect the STOP button. That did not change anything.
The next step was then look at the ignition system, so in the case the breaker contact. (The Yamaha 5 BS has one breaker contact and no transistor ignition.) Remove the wire throw, remove the flywheel, and then remove the entire ignition system. By measuring the coil by means of ohmmeter seems to be ok, check the breaker contact for continuity and determine that only when it is compressed will it still have continuity. Now first order a new breaker contact and immediately with the small capacitor (is intended to break the break contact breaker contact).
After the new breaker contact and the new capacitor arrived (35 EURO) reassemble everything. New bump test and now you can see a spark well.
Screw in the spark plugs and connect and test the fuel tank.
Well, engine starts.