This quickly established problem number one, the starter motor slipping out because of worn teeth on the flywheel as well as poor engagement from the starter motor.
So the first few jobs were to fix the starter motor clutch and refurb the starter motor. The flywheel was also set back by adding a shim to get better contact with the starter motor drive. Having sorted the starter motor, and temporarily fixed the flywheel, the next problem was the ignition system.
The engine originally had a CDI magnet ring type ignition. These produce a huge spark and don't require an alternator as they produce their own power. This had obviously broken and was replaced by the previous owner who made up a distributorless points ignition system working on the wasted spark principle (2 sparks per cylinder for every rotation). The home made ignition system produced a weak spark and made starting the engine very difficult. The previous owner had obviously had some major issues getting the engine/boat to work as when I looked at the cam/points cover (see pic) he had stamped the words "ABANDON ALL HOPE ALL YE WHO ENTER HERE" onto the inside of the cover. Amusing at the time but if i'd found it earlier, i'd probably have taken this excellent advice!
Hidden advice from the previous owner! Look closely...
The Rotax engine in its early days with Mk1 ignition system - later ditched due to bad vibration
Engine rebuild in progress - NEVER USE EASY START ON OLD ENGINES!!!
New MSD digital programmable ignition system
Old mangled and off balance flywheel
Rebuilt engine with custom made flywheel following "Easy Start" disaster. A magnetic trigger is installed on the rear face of the flywheel to trigger the ignition sparks
Custom made trigger pickup mounting plate and twin trigger pickups. These control the twin coil packs
With new exhaust header and ignition cover (from a Kawasaki)
With the ignition system sorted, it was time to sort the carb. I ordered a full set of replacement parts from a very helpful and top bloke called Ralph Engelbrecht, a specialist from Germany with a good supply of BING carb parts. I also discovered the fuel pump wasn't working properly, and ordered a replacement.
New parts from BING carburettors - They have lots of old spares in stock!
Old carb float being removed
The engine then went into the boat and all the wiring for the new ignition system was connected up using waterproof Perma Seal connectors and Deutsch connectors. I replaced the fuel lines and fitted new in-line fuel filters. The engine fired up first time and now provides reliable first time starts every time and runs beautifully. Well worth the money and time for the ignition and carb parts.
Everything in place and wiring done