30 hp 1986 Back fire and won't start

[kyong1]

After a few parts changed as early as Dec 2012.. I been curirous what or why the motor is not engaging.. I repair a water pump, head gasket, termastat, stator, fuel kit and carburator kit...After a couple of trys I've kind of decided not to waste any more time. I will be returing home after a six month deployment and of course I really would not like to waste any more time and $$#.
Appreciate any comment or suggessions:help:It all started with milky spark plugs......... Figuer I give it a try to replace gasket and little things..

Thanks aHead OF time..

 

[JB]

Re: 30 hp 1986 Back fire and won't start

True backfire only occurs if the spark plug fires when the exhaust ports are open. The most common cause is mixup of the plug wires, the second most common is a sheared flywheel key or badly mis-timed stator.

Some folks call a sneeze a backfire. That is caused by too lean fuel/air mix from the carb(s).

 

[bonz_d]

Re: 30 hp 1986 Back fire and won't start

Those are actually very nice lil engines and when they are running are usually problem free.
If you have the head gasket already replaced then the hardest parts done. JB said it but didn't ask, is it backfireing thru the carb or the exhaust? What do you mean by the engine is not engaging?

 

[kyong1]

Re: 30 hp 1986 Back fire and won't start

Oh I meant it doing start up just crank over.

 

[Chinewalker]

Re: 30 hp 1986 Back fire and won't start

My bet is the coil wires got switched around when you were replacing ignition parts... Won't hurt to swap them and see. If memory serves, the orange wire with blue tracer fires the top plug.