1984 omc 2.5 liter with 400 series stern drive

[Omc-nightmare]

Ok here's my problem. I bought the boat in 2005 it's a pennyan 16' ti sport I/o. The boat did sit for few years. This year I got the time and money to rebuild her. The original engine was replaced in 05 it has maybe 150 hours it. This year I replaced the exhaust manifold, fuel pump, spark plugs and also the coil. The engine runs and sounds great but on the water it suddenly dies and back fires through the carb. Also the new spark plugs are already fowled badly covered in carbon. My question is where to begin. I have a gut feeling its the ignition system. My friend seems to think the carb is making it run to rich and to rebuild the carb. Also please excuse my grammar I am writing this on my phone on the boat. Thanks

 

[Bondo]

Re: 1984 omc 2.5 liter with 400 series stern drive

Ok here's my problem. I bought the boat in 2005 it's a pennyan 16' ti sport I/o. The boat did sit for few years. This year I got the time and money to rebuild her. The original engine was replaced in 05 it has maybe 150 hours it. This year I replaced the exhaust manifold, fuel pump, spark plugs and also the coil. The engine runs and sounds great but on the water it suddenly dies and back fires through the carb. Also the new spark plugs are already fowled badly covered in carbon. My question is where to begin. I have a gut feeling its the ignition system. My friend seems to think the carb is making it run to rich and to rebuild the carb. Also please excuse my grammar I am writing this on my phone on the boat. Thanks

Ayuh,.... Welcome Aboard,.... I agree with yer Bud,....

 

[Silvertip]

Re: 1984 omc 2.5 liter with 400 series stern drive

Or fix the choke.

 

[Howard Sterndrive]

Re: 1984 omc 2.5 liter with 400 series stern drive

replaced with what in '05? I would check advance weights and springs under the points plate. I'd probably do a compression test too as a matter of elimination. Watch the choke to make sure it is opening fully when warmed up. The original carb/manifold had a heat pipe that liked to come loose in the cast iron manifold.

 

[Omc-nightmare]

Re: 1984 omc 2.5 liter with 400 series stern drive

The engine was replaced in 05 long story bad fuel pump cause engine to explode sent a piston through the block. The boat still has original carb with the stove pipe the replacement manifold is a direct replacement from an old parts warehouse in Washington. The choke is opening. I think all the way. I will double check the linkage to the choke

 

[Omc-nightmare]

Re: 1984 omc 2.5 liter with 400 series stern drive

Ok the choke and choke plate seem to be moving ok when lever is up plate is straight up and down. Like I said it will run great them die on plane. I started it in the drive today. Started first try then sounded like it was missing. Could this just be the fowled spark plugs or something else

 

[Levinz11]

Re: 1984 omc 2.5 liter with 400 series stern drive

I don't have anything of value to add...but I dig the your user name :rockon:

 

[Bondo]

Re: 1984 omc 2.5 liter with 400 series stern drive

Ok the choke and choke plate seem to be moving ok when lever is up plate is straight up and down. Like I said it will run great them die on plane. I started it in the drive today. Started first try then sounded like it was missing. Could this just be the fowled spark plugs or something else

Ayuh,.... Yer Bad carb caused the spark plugs to foul,.....

 

[Boomyal]

Re: 1984 omc 2.5 liter with 400 series stern drive

A shame he thinks his nightmare is due to having an OMC. He is lucky he did not face the black anchor.

If the poster, OMC nightmare, had purchased an ill attended Mercruiser, he would have had to use "Rube Goldberg -nightmare' as a handle.

 

[Levinz11]

Re: 1984 omc 2.5 liter with 400 series stern drive

A shame he thinks his nightmare is due to having an OMC. He is lucky he did not face the black anchor.

If the poster, OMC nightmare, had purchased an ill attended Mercruiser, he would have had to use "Rube Goldberg -nightmare' as a handle.

Agreed.

 

[Omc-nightmare]

Re: 1984 omc 2.5 liter with 400 series stern drive

I was only trying to be cleaver, with my username. I love my omc. When she is running she is more reliable then my friends merc.