Someone Please HELP!!!

[jtegidgo]

1978 80hp Mercury with thunderbolt ignition. I have spark at all four cylinders, new plugs, new wires, nice thick spark at plugs, checked compression (120 psi at all four cylinders), ohmed out stator, checked trigger and it was within spec, mercury switch operable, switch box can't be problem cause I have spark at all four cylinders. I sprayed gas in cylinders and engine won't even pop. Drained battery trying to get this thing to run. I've checked everything I know about. Need some opinions. Thanks

 

[ZmOz]

Re: Someone Please HELP!!!

Checked the timing? Are the plugs wet with fuel before you spray any into the cylinders/carbs? I had a similar problem recently...the timing was way, way off...

 

[AMD Rules]

Re: Someone Please HELP!!!

Spark plug firing sequence?

 

[jtegidgo]

Re: Someone Please HELP!!!

I checked timing as per merc manual over the weekend and it seemed fine at 3 degrees, chked TDC at #1 as well. In the process I found an arc at one of the coils. I replaced the coil and expected it to fire. Checdked plugs and they are not wet like I would think after all the cranking I did, but I was priming cylinders. I would think it should try to start. Over the weekend I checked the float and cleaned the carbs. All looks good for the fuel system, new diaphram in the fuel pump as well.

 

[jtegidgo]

Re: Someone Please HELP!!!

AMD how do I check firing sequence?? Have not done that yet.

 

[andy6374]

Re: Someone Please HELP!!!

Try spraying a 50:1 mix directly into the carb and see if it fires.<br /><br />-andy

 

[jtegidgo]

Re: Someone Please HELP!!!

Tried that straight into cylinders by removing plugs no luck. thats what confuses me.

 

[ZmOz]

Re: Someone Please HELP!!!

Originally posted by Jtregidgo:<br /> Tried that straight into cylinders by removing plugs no luck. thats what confuses me.

Do it in the carbs. Putting gas in the cylinders is just going to flood it.

 

[AMD Rules]

Re: Someone Please HELP!!!

Firing sequence should be 1-3-2-4, top cylinder is #1<br /><br />Wires from switchbox:<br />Coil #1 - Green wire<br />Coil #2 - Green-White wire<br />Coil #3 - Green-Red wire<br />Coil #4 - Green-Black wire<br /><br />Like ZmoZ suggests, try spraying 50:1 into the carb throats.<br /><br />Before the problem started, had anything been changed or recently tampered with?

 

[dakk1]

Re: Someone Please HELP!!!

I'm with ZmOZ and AMD on that. The old Air Fuel Fire Compression. Kinda bypassing the Air part. Also, how did you check your spark?<br /><br />Dave..

 

[jtegidgo]

Re: Someone Please HELP!!!

Engine sat for many years and was my grandfathers. The best i've gottten out of it was this weekend I got it to pop a few times now nothing. You could be right in that I am flooding it. The way I checked spark was by allowing the plug to arc to the block. Once I changed out the bad coil the spark thickened up and seems correct. All the settings have not been changed yet. Timing settings seemed correct, carb settings seemed correct, I really have not found too much wrong with the engine minus the bad coil. Is there a good way to aspirate the gas mix into the carb. <br /><br />Guys I appreciate the help I was at my wits end on this one.

 

[AMD Rules]

Re: Someone Please HELP!!!

Double check to make sure those electrons will jump a 3/8" gap. Sometimes just a spark isn't enough... it needs to be strong.<br /><br />Clean the plugs good, and try using a spray bottle (like one of the window cleaners that have the stream setting) or shringe to squirt the fuel.<br /><br />When you prime the fuel bulb, does it go firm? Any gas dripping out of the carbs? When you loosen the carb drains, are the bowls full of fuel? Fresh fuel mixture?

 

[jtegidgo]

Re: Someone Please HELP!!!

Bulb does go firm, just replaced it to eliminate that as a concern, fresh fuel is in the bowl when I remove the drains, but gas does come out of the venturis I assumed it was cause I flooded it when my numerous attempts to start.

 

[Clams Canino]

Re: Someone Please HELP!!!

VERY hard to flood these...<br /><br />-W