Dead Cylinder - Evinrude 48 HP SPL - HELP!

papakevin

Petty Officer 2nd Class
Joined
Apr 10, 2005
Messages
103
OK, I'm the guy who had the problem with the boat motor running, but stalling when I tried to put it into gear in the water.<br /><br />Well, I did a test on the engine out of the water (running with water muffs) and I did the old spark plug test... pulled each spark plug to see what happens. With the motor running, I pulled the top spark plug, and there was no difference at all. None. Zero. Nada. I replaced it, then pulled the bottom plug wire and the engine died. <br /><br />What are my next steps for troubleshooting the dead cylinder? I do not have a compression tester, but I guess I could buy one if needed. Before I do that, can someone help me with the process for test for proper spark? Since this is running on only one cylinder anyway right now, would it hurt anything if I disconnected the top wire, then moved my bottom wire up (leaving the original top wire disconnected or course) to see if it would start using only the top cylinder? :(
 

OBJ

Supreme Mariner
Joined
Dec 27, 2002
Messages
10,161
Re: Dead Cylinder - Evinrude 48 HP SPL - HELP!

Hey Kev!..... Do this.....rig a spark tester to see the spark. Swap the leads from the power pack to the coils. If the problem follows...ie...no spark on the lower plug, replace the power pack. If the problem stays with the upper cylinder, replace the ignition coil.
 

papakevin

Petty Officer 2nd Class
Joined
Apr 10, 2005
Messages
103
Re: Dead Cylinder - Evinrude 48 HP SPL - HELP!

OK, running out of daylight, but I'll try it. I'm also seeing some gas/oil mixture starting to puddle up under the carbs (again they're new). I'm assuming this might be from the dead cylinder not burning the gas, right? I'll work on the spark test....
 

papakevin

Petty Officer 2nd Class
Joined
Apr 10, 2005
Messages
103
Re: Dead Cylinder - Evinrude 48 HP SPL - HELP!

Update. Spark on the top cylinder looks good, so I'm assuming it is working. As I said, someone installed two new carbs on this thing at the end of last year. What can I do to check the adjustments of them? I'm a little worried about the fuel (not a lot but it's there) starting to collect in the motor housing, but I can not find a leak anywhere. Help please!
 

fireman57

Captain
Joined
Aug 24, 2004
Messages
3,811
Re: Dead Cylinder - Evinrude 48 HP SPL - HELP!

Fix your spark problem first to make sure that it isn't unburnt fuel. If it continues then wipe everything clean and start your engine. Watch for where the fuel comes from. Shouldn't be too hard to find if it is pooling. Don't rev your engine in neutral on the muffs.
 

rodbolt

Supreme Mariner
Joined
Sep 1, 2003
Messages
20,066
Re: Dead Cylinder - Evinrude 48 HP SPL - HELP!

have you run a compression test? thats the first step in any two stroke diagnoses. then test that spark can jump a 7/16ths gap. if the first two are good its time to chase fuel fairies
 

papakevin

Petty Officer 2nd Class
Joined
Apr 10, 2005
Messages
103
Re: Dead Cylinder - Evinrude 48 HP SPL - HELP!

Compression is good and spark is good. It appears I'm chasing "fuel fairies" now. Let the games begin...<br /><br />Thanks to everyone for the help and keep it coming.
 
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