1994 140hp evinrude

Mrobi

Seaman Apprentice
Joined
Mar 7, 2021
Messages
48
I have a 1994 evinrude 140hp. I took my boatvout yesterday and could only reach 36mph/4100rpms. It was hitting 43mPh/5200rpms. With in the last year I have replaces plugs & wires, power pack, themostat, coil packs, impeller, rebuilt all 4 carbs(all chasing another problemthat y'all help me remedy) and all seals in the lower unit. The only thing I did before I noticed it was not reaching WOT, was replaced the fuel quick disconnect with a permanent connection because I started losng prime after adding the quick disconnect. Im no longer losing prime but now I can't reach wot speeds. Any suggestions
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
38,964
Nobody can see, touch or hear your motor !----You need to post information.-----The 2 most elegantly tests are #1 compression test, post the actual values here.---#2 is a spark test , does spark jump a gap of 3/8" or more on each lead, yes or no?----Then again it could be the flywheel key sheared.-----Or seagull feather stuck in a reed valve.
 

Mrobi

Seaman Apprentice
Joined
Mar 7, 2021
Messages
48
I'm guessing you lost one cylinder somehow.....spark, fuel, compression....something. what story do the spark plugs tell?
Thanks
I'm guessing you lost one cylinder somehow.....spark, fuel, compression....something. what story do the spark plugs tell?
The bottom starboard plug appeared fouled but definitely has spark, lots of spark. The other 3 plugs looked ok. Gonna rent a compression tester tomorrow.
 

Mrobi

Seaman Apprentice
Joined
Mar 7, 2021
Messages
48
Nobody can see, touch or hear your motor !----You need to post information.-----The 2 most elegantly tests are #1 compression test, post the actual values here.---#2 is a spark test , does spark jump a gap of 3/8" or more on each lead, yes or no?----Then again it could be the flywheel key sheared.-----Or seagull feather stuck in a reed valve.
Thanks

The bottom starboard plug appeared fouled but definitely has spark, lots of spark. The other 3 plugs looked ok. Gonna rent a compression tester tomorrow.
Thank you
 

saltchuckmatt

Commander
Joined
Jul 19, 2019
Messages
2,916
Thanks

The bottom starboard plug appeared fouled but definitely has spark, lots of spark. The other 3 plugs looked ok. Gonna rent a compression tester tomorrow.
Spark means nothing....buy an inexpensive spark gap tester like Racerone suggested...cheap at any auto parts store. Could be an ignition coil.
 

Mrobi

Seaman Apprentice
Joined
Mar 7, 2021
Messages
48
Nobody can see, touch or hear your motor !----You need to post information.-----The 2 most elegantly tests are #1 compression test, post the actual values here.---#2 is a spark test , does spark jump a gap of 3/8" or more on each lead, yes or no?----Then again it could be the flywheel key sheared.-----Or seagull feather stuck in a reed valve.
So im understanding you. I need to spread the gap from .030" to 3/8(.375)" and see if its still sparking?
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
38,964
Sparkplugs are not used for this test.----Buy a spark tester.----Or use some wire / glue and carboard to make one.
 
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