hey guys,
question for you.
I have a 1978 johnson 75 stinger. bought it as part of a project boat, got it up and running and had it out for first test run in water. ran ok for an hour or so, then water pump stream got weak and it would bog and die when opening up the throttle (two different issues completely). I expected some issues since I guess the motor had been sitting for years.
anyway, I rebuilt the water pump and put new t-stat in and the water seems fine now, god strong stream from the tell tale and i can hold my hand on the engine.
the engine bog is another issue. same story ive seen here in the forums, runs fine in the driveway, but under load wont rev up.
i checked compression in all 3 cylinders - compression is good.
while running, I blocked front of the each carb, and when I blocked the top one there was no change in the engine at all which told me is proably wasnt running on that cylinder.
i used a spark gap tester and checked spark in all 3 cylinders. from what ive read here, spark should jump 7/16 gap. the bottom two cylinders will do that, I can see the spark, but I would use the word "strong" to describe it. the top cylinder there is no spark at all. even if i close the gap on the gap tester, there is nothing.
I replaced the coil on the top cylinder and still nothing.
I'm going to dive into manual and see what else I can find online, but if any of the experts here have info on what to look at next, the help would be appreciated. this is the first outboard ive worked on, learned alot so far, but still learning..
thanks!....
scott
question for you.
I have a 1978 johnson 75 stinger. bought it as part of a project boat, got it up and running and had it out for first test run in water. ran ok for an hour or so, then water pump stream got weak and it would bog and die when opening up the throttle (two different issues completely). I expected some issues since I guess the motor had been sitting for years.
anyway, I rebuilt the water pump and put new t-stat in and the water seems fine now, god strong stream from the tell tale and i can hold my hand on the engine.
the engine bog is another issue. same story ive seen here in the forums, runs fine in the driveway, but under load wont rev up.
i checked compression in all 3 cylinders - compression is good.
while running, I blocked front of the each carb, and when I blocked the top one there was no change in the engine at all which told me is proably wasnt running on that cylinder.
i used a spark gap tester and checked spark in all 3 cylinders. from what ive read here, spark should jump 7/16 gap. the bottom two cylinders will do that, I can see the spark, but I would use the word "strong" to describe it. the top cylinder there is no spark at all. even if i close the gap on the gap tester, there is nothing.
I replaced the coil on the top cylinder and still nothing.
I'm going to dive into manual and see what else I can find online, but if any of the experts here have info on what to look at next, the help would be appreciated. this is the first outboard ive worked on, learned alot so far, but still learning..
thanks!....
scott