Merc not starting

[Vagle32]

My 1978 900 6 cyl Mercury will not start. I have good blue spark, fuel pump is working, battery is good, fuel in the carbs. Now it will try to start so turn the key fly wheel spins. Some times it catches and wants to start but then tells me no. I'm wondering if I can get an input to try and figure it out. Not to mention I have 5 kids on my butt to get it done lol. I'm sure something like this has been posted but figure I would shoot it out there. TIA

 

[Mohawkmtrs]

Push the choke button while starting with the warm up lever in the up position.

 

[Vagle32]

There is not a warm up lever on these controls!!

 

[roscoe]

If no warm up lever, push or pull the neutral only button and then advance the throttle to wide open.
And make sure the choke is working.

 

[jimmbo]

“Advance the throttle to wide open”

Not the best advice, guaranteed to cause problems

 

[roscoe]

“Advance the throttle to wide open”

Not the best advice, guaranteed to cause problems

Have a better way to get the fuel flowing ?

 

[Vagle32]

Ok so from what I read these old mercs. Love the gas.(my wife sure doesn’t feel the same). It try’s to start but seems to be when I let off the key from cranking. I’m not sure if it’s the carbs they look pretty clean. The starter is engaging. I also checked the solenoid that appears to be good! I made sure the timing is good by following the manual. I have checked the fuel pump and that is getting flow. It’s new gas. Electric choke works and it also has a manual choke on the motor.
Battery when fully charged is 13 v

Any other ideas? TIA

 

[Chris1956]

On those old distributor Mercs, the motor will seem to fire when cranking, but in reality the trigger is bad. CDI electronics has a trigger test for those motors. I would recommend you run the trigger test.

As you may or may not know, the distributor rotor is non-removeable, very fragile and $200+ to buy. Likewise the trigger is $200+ to buy. I would recommend a service manual as neither is straightforward to install.

 

[Vagle32]

Yes I replaced that already. And still no start!

 

[Chris1956]

OK then, choke the crap out of her when starting. Throttle advanced a bit, fuel primer pumped up hard.

Crank her holding the choke button down until she fires.

Spray some 50::1 mixed fuel into the carb throats, and repeat starting procedure. If that doesn't work, you have other issues, like bad compression, engine out of time, arcing spark plug wires. bad ign components...