enginesilo
Contributing Member
"I went to check out a boat an
"I went to check out a boat and I did the spark test where you remove one wire at a time while the engine is running to see if the RPM's drop down.
I tested this with all 4 and one of the cylinders seemed to drop a tiny bit, but not as much as the others. The cylinder that did this was the top right side cylinder if you were sitting in the boat driving.
The boat was idling around 1100 to 1200 rpm's or so and when I removed the 3 others it would drop about 100 to 200 rpm's. When I pulled this top right cylinder spark wire it would drop maybe 100 or so. You could hear it change, but didn't change as much as the other 3.
I put the spark plug cap close to the spark plug with a pair of pliers and you could hear the strong spark jumping hard and making the link between the cylinders and the engine would then pep up a bit and rev a little higher, but again it wasn't as noticeable as the other 3.
The engine is a 1999 or a 2000 (Still confirming) Johnson 115HP model # J115PLSSB, which I think is a carbureted model. I opened the cover and it was immaculate, looked almost brand new inside and ran great overall. This was the first time it ran after being winterized all season. It took a good few times to get it cranking, then once it fired up it ran like a dream. It idled perfect and started without any throttle, just a little choke if any.
Think I might have an issue here? If I buy I will probably have it surveyed, but before I get to that point and tips you guys can share will be helpful."
"I went to check out a boat and I did the spark test where you remove one wire at a time while the engine is running to see if the RPM's drop down.
I tested this with all 4 and one of the cylinders seemed to drop a tiny bit, but not as much as the others. The cylinder that did this was the top right side cylinder if you were sitting in the boat driving.
The boat was idling around 1100 to 1200 rpm's or so and when I removed the 3 others it would drop about 100 to 200 rpm's. When I pulled this top right cylinder spark wire it would drop maybe 100 or so. You could hear it change, but didn't change as much as the other 3.
I put the spark plug cap close to the spark plug with a pair of pliers and you could hear the strong spark jumping hard and making the link between the cylinders and the engine would then pep up a bit and rev a little higher, but again it wasn't as noticeable as the other 3.
The engine is a 1999 or a 2000 (Still confirming) Johnson 115HP model # J115PLSSB, which I think is a carbureted model. I opened the cover and it was immaculate, looked almost brand new inside and ran great overall. This was the first time it ran after being winterized all season. It took a good few times to get it cranking, then once it fired up it ran like a dream. It idled perfect and started without any throttle, just a little choke if any.
Think I might have an issue here? If I buy I will probably have it surveyed, but before I get to that point and tips you guys can share will be helpful."
