228/305 mercruiser ignition problems

[dacaptain]

I have a 1978 228/305 mercruiser with points ignition,i cant get fir to my plugs,i changed the condensor,points,coil,rotor button and cap...nothing. Removed reset breaker and "hot wired" together also,still nothing. HELP! I had a rope in the prop,choked and killed engine and now wont crank,have no idea. Thanks guys for any help!

 

[Haut Medoc]

Re: 228/305 mercruiser ignition problems

First, welcome to iboats......
So the boat wouldn't restart after the wind up?....

 

[Haut Medoc]

Re: 228/305 mercruiser ignition problems

So it wont crank at all?
From your description, I would suspect you may have done lower end damage....Possibly......
How do you know that you are not getting spark?
Did you check for voltage at the coil + terminal with the key in thr 'run' position?
Does the starter sound like it wants to crank but won't?
I guess where I'm going with this is I doubt that you created an electrical problem when you ran over the rope......
If the starter sounds like it wants to do something but won't, I would pull thre drive & see if it will crank then....
The other possibility is hydrolock......
To check for that, pull the plugs & see if you can turn it over by hand using a suitable socket at the pulley on the harmonic balancer & turning in the direction of normal rotation.....
If you can & no water comes out, then it is time to trouble shoot the starter & ign system....If it won't turn, the drive will have to come off & repeat the step above......

 

[Trent]

Re: 228/305 mercruiser ignition problems

Take a look at the shift interrupt switch.. The lower shift cable could be binding and grounding out the coil.

 

[dacaptain]

Re: 228/305 mercruiser ignition problems

So it wont crank at all?
From your description, I would suspect you may have done lower end damage....Possibly......
How do you know that you are not getting spark?
Did you check for voltage at the coil + terminal with the key in thr 'run' position?
Does the starter sound like it wants to crank but won't?
I guess where I'm going with this is I doubt that you created an electrical problem when you ran over the rope......
If the starter sounds like it wants to do something but won't, I would pull thre drive & see if it will crank then....
The other possibility is hydrolock......
To check for that, pull the plugs & see if you can turn it over by hand using a suitable socket at the pulley on the harmonic balancer & turning in the direction of normal rotation.....
If you can & no water comes out, then it is time to trouble shoot the starter & ign system....If it won't turn, the drive will have to come off & repeat the step above......

 

[dacaptain]

Re: 228/305 mercruiser ignition problems

The engine spins over like its going to crank,i put a tester,i got voltage on + post on coil,engine spins,gets fuel but no spark at plug.

 

[dacaptain]

Re: 228/305 mercruiser ignition problems

Take a look at the shift interrupt switch.. The lower shift cable could be binding and grounding out the coil.

 

[dacaptain]

Re: 228/305 mercruiser ignition problems

Im new to the i/o thing...used to working with diesels...where would the interruptor switch be located....or about where? thanks

 

[Don S]

Re: 228/305 mercruiser ignition problems

You mentioned you installed new point, did you set the points properly? Is the coil wire in the center of the distributor cap ok?
With the ign. switch in the run position, do you have power to the + terminal of the coil?

 

[Haut Medoc]

Re: 228/305 mercruiser ignition problems

http://cgi.ebay.com/ebaymotors/Merc...92229643QQcategoryZ124104QQrdZ1QQcmdZViewItem


http://cgi.ebay.com/ebaymotors/MERC...095168305QQcategoryZ31283QQrdZ1QQcmdZViewItem


Looks like this..........
Yours is probably located by the starboard riser.....

 

[Reel Poor]

Re: 228/305 mercruiser ignition problems

Is the coil firing? Could be a bad coil wire.

The new point contacts may have a coating on them. I have had to lightly sand/file on many sets of new points to get them to make contact. Also check the wire inside the distributer that connects to the points and make sure it's not touching the distributer housing.

Is the rotor turning when you crank the engine over?

It could be a bad tach. Disconnect the tach from the coil neg post (grey wire) and test for spark again.

 

[dacaptain]

Re: 228/305 mercruiser ignition problems

Take a look at the shift interrupt switch.. The lower shift cable could be binding and grounding out the coil.

 

[dacaptain]

Re: 228/305 mercruiser ignition problems

Thanks! it was the interrupt switch...disconected it and boat cranks and runs fine! Thanks!

 

[180shabah]

Re: 228/305 mercruiser ignition problems

Your not done yet. You know why it wouldn't run, leaving that switch disconnected is not the answer. Without that switch working, you will not be able to shift OUT of gear. You need to look closely at the lower shift cable as the probable cause.

 

[Haut Medoc]

Re: 228/305 mercruiser ignition problems

What Shabah said....
You will not be able to get out of gear unless you kill the engine....
There is an issue that needs to be dealt with...
You cannot just disable it & expect all to be well...

 

[dacaptain]

Re: 228/305 mercruiser ignition problems

The boat runs fine...the switch was bad,nothing in a bind and without the switch when i ran it out yesterday it came in and out of gear with no problem...the switch is stuck in closed position (to interrupt the coil i guess) but the boat has been running fine now,thanks again guys.

 

[Reel Poor]

Re: 228/305 mercruiser ignition problems

If you don't replace the switch you will be back on here asking why you boat won't stay in gear in short time. The switch interrupts the ignition to momentarily kill the engine so the drive load on the dog teeth is dropped, allowing the gears to disingauge. Without the interrupt you are forcing the shift mechanism and it will wear out the dog teeth.

Drive it as it is and you will rebuild the drive in due time. Replace the switch and you have fixed the problem you were having.