More Help; Still Won't Start

[epundt]

1984 Johnson GT 150. Checked gas, no prob. Cleaned Carbs, new plugs, flywheel key is OK, compression 84 lbs all 6 cyls. Still won't start. Backfires. This engine is a cross between an 83 and 84. Should run on leaded gas, we are running 89 octane unleaded. Is there anyway to check timing? Acts like it jumped time. Could it be the control box? There is a prob. there, oil buzzer goes off, that sensor is not hooked up to anything.The thingy attached to the ignition switch came off, engine died, put it back on and it ran fine. At wits end. Any ideas, will try anything.

 

[Joe Reeves]

Re: More Help; Still Won't Start

The flywheel nut must be torqued to exactly 105 foot pounds for a low amp charging system, and to 145 foot pounds for a 35 amp charging system.<br /><br />Anything less will result in a sheared key (sheared after you inspected it)that throws the engine out of time, and which will also damage the flywheel and crankshaft tapers.<br /><br />Warning horn sounding without any sensor wire attached to it indicates a faulty horn.<br /><br />The engine must turn up to or over 300 rpms in order to generate spark. The compression reading you state might indicate a slow cranking rpm. At any rate, double check the compresion and spark. The spark with the plugs out should jump a 7/16" gap with a strong blue flame on all cyls.<br /><br />The thinggy (whatever) on the ignition switch is most likely a kill switch.<br /><br />Hopefully you checked and thoroughly cleaned the four (4) brass fixed high speed jets in the carbs. Fuel must flow through them before it can flow to any other fuel passageway. Locate them via your service manual.