ENGINE WON'T STAY RUNNING

[JACK HAMMER]

I am helping out a friend with an older boat, not a MATE unfortunately, and since you guys helped me out so well before with my MATE, I figured I would come pack to the experts! Its an older system, 165 HP Merc, straight six, that will run for a couple seconds then stall, It has a breaker point ignition systen, and it states on the coil that a resistor between the primary and secondary terminals should be used. Without this resistor would it give these conditions? It didn't have one when I became involved with this project, and apparently hasn't been running in awhile. Any help would be appreciated!

[JACK HAMMER]

I am helping out a friend with an older boat, not a MATE unfortunately, and since you guys helped me out so well before with my MATE, I figured I would come pack to the experts! Its an older system, 165 HP Merc, straight six, that will run for a couple seconds then stall, It has a breaker point ignition systen, and it states on the coil that a resistor between the primary and secondary terminals should be used. Without this resistor would it give these conditions? It didn't have one when I became involved with this project, and apparently hasn't been running in awhile. Any help would be appreciated!

[ckmate225]

Jack,
Check for spark first if it seems OK then check the fuel. Will it only run with the choke on? If its a built in tank it may have had a bunch of water in it. Put some in a glass jar and see if you can see it separate. Also smell it if it smells a little rancid get rid of it and put in some fresh stuff. After that it may be carb job time. Let me know how you make out.

225

[happy]

whats happening in the points system... with out the ballast resistor the coil is getting a constant 12 volts.. in this application it will burn the points in a relativly short period of time.. the ballast resistor reduces the voltage to the distributor to 6 volts. .. the way this system works while your cranking the r terminal on the starter soliniod feeds 12 volts to the coil, after the engine starts, the key switch is reverted to the run position which feeds 12volts to the ballast resistor, which in turn delivers 6 volts to the coil..

the easy fix on the coil is to replace the coil with an internal resisted coil.. thus the ballast resister is no longer needed, and one less item to corrode and break.. (good thing on a boat)

the next thing i would check is to be sure the wiring is correct on the engine itself.. when the ballast was originally removed... did they repair the wiring harness in a manner which would not short the system out..

now turn your key to the run position, and take a voltage check at the coil.. should be 12 volts, (or battery voltage) replace the points and condensor, and check for spark.. if you don't have 12 volts with the key in the run position , you may have a bad key switch, or a wiring problem from the key to the engine harness.

three things make an engine run... spark , fuel, and air.. other things to check if you continue to not run

fuel system carburator
compression check..

hoped this helped

[happy]

almost forgot this one... a shorted out tack will ground the ignition system out too.. it should be one of the two gray wires on the negative side of the coil.. good luck

[JACK HAMMER]

You guys are awesome! I saved a bunch of time troubleshooting. Next problem...I have found the carb main jets were plugged and would only stay running when you work the throttle concictently...it has a Rochester 2 barrel...I have bought the rebuild kit, as well as the float...but i want to make sure everything is in there, as it looks as though someone already had it apart....where can I get some illustrations? In the kit there are two ball bearings, and I can't seem to locate any in the carb I have....any ideas?

[daren34]

they are for the acelerator pump

[Big Dave]

All Mercruiser engines are equiped with a non-resistor coil and use a resistance wire to the coil. NO EXTERNAL RESISTOR REQUIRED!!!!!
There is a "t" that holds down one of the checkballs under the venturi boosters, the other one is below a screen below the accelerator pump.
Check out mercruiserparts.com for a blow up of the carb. also the kit should have a good blow up and float spec's on it

[JACK HAMMER]

Thanks BIGDAVE...that website answered all my questions! Thanks for the help!

[Deluge]

ON this topic.. advise,,
put in water wouldnt fire up
sounded good, choke sounded good, everything sounded as it should, any idea on this.
it was runninging great last time. so I was rather surprised,