Mullerhawk
Seaman Apprentice
- Joined
- Aug 2, 2011
- Messages
- 37
Hi Guys,
I bought a 1977 25HP Johnson Seahorse (25BA77H) for a measly $70 due to the fact it is supposed to be broken (died on previous owner after a while of running). The powerhead shows apparent scorching from overheating (paint is yellow and some burnoff in the corners of the cylinder head).
He said that the water channel was filled with gunk and he cleaned it out. And that it was running after that. Of course I was sceptical, but it's a no brainer for that amount of cash. I can always strip it for spare parts or sell it for the tripple amount of cash. But!
I made it my mission to get the motor running. I cleaned everything, did a pressure test (110 PSI on both cylinders). Checked the cylinder walls for scratches (through the spark holes) but found no appare problem. Then I tried to run it in a barrel. It takes about 10 pulls then it sneezes and goes BANG! Tried some more times but the same result - no ignition.
Then I noticed that one of the cables comming from the powerpack was metodicly cut and stripped, and the same on the other side (PP: Brown/Yellow, Stator: Black/Yellow - check the pictures!). It looked allmost like a connection was missing so I was wondering if that was because of the older 3 wire PP design (even if this has four). I connected it and tried again - but still the same sneezing with a bang. Should it even be connected?!
I checked the link-and-sync and it looked quite good (not perfect). But at WOT the CAM armature is about 1-2 inches from the ignition timing screw which looks a bit strange! Could the sneezing be from the ignition timing is off? From my understanding timing can only be adjusted at WOT with a timing light? Is there any other way to do a rough setting (should have 34degree according to the sticker on the engine)?
Or what else could cause the ignition sneezing and miss detonations?!
Thankful for all the help I can get to get this old geezer running again
// Michael Vinter
I bought a 1977 25HP Johnson Seahorse (25BA77H) for a measly $70 due to the fact it is supposed to be broken (died on previous owner after a while of running). The powerhead shows apparent scorching from overheating (paint is yellow and some burnoff in the corners of the cylinder head).
He said that the water channel was filled with gunk and he cleaned it out. And that it was running after that. Of course I was sceptical, but it's a no brainer for that amount of cash. I can always strip it for spare parts or sell it for the tripple amount of cash. But!
I made it my mission to get the motor running. I cleaned everything, did a pressure test (110 PSI on both cylinders). Checked the cylinder walls for scratches (through the spark holes) but found no appare problem. Then I tried to run it in a barrel. It takes about 10 pulls then it sneezes and goes BANG! Tried some more times but the same result - no ignition.
Then I noticed that one of the cables comming from the powerpack was metodicly cut and stripped, and the same on the other side (PP: Brown/Yellow, Stator: Black/Yellow - check the pictures!). It looked allmost like a connection was missing so I was wondering if that was because of the older 3 wire PP design (even if this has four). I connected it and tried again - but still the same sneezing with a bang. Should it even be connected?!
I checked the link-and-sync and it looked quite good (not perfect). But at WOT the CAM armature is about 1-2 inches from the ignition timing screw which looks a bit strange! Could the sneezing be from the ignition timing is off? From my understanding timing can only be adjusted at WOT with a timing light? Is there any other way to do a rough setting (should have 34degree according to the sticker on the engine)?
Or what else could cause the ignition sneezing and miss detonations?!
Thankful for all the help I can get to get this old geezer running again
// Michael Vinter
