troubleshooter
Recruit
- Joined
- Jun 25, 2012
- Messages
- 2
Dear fellow boaters, I hope I can get some good advice from you:
My Johnsone Outboard starts right up now and ran fine for the last months UNTIL suddenly inmidst of a tour on a long day ? it wouldnt take any more gas if you go beyond 2000 - 2500 RPM ? It is not "stuttering" as if the ignition would go on and off, it is just not picking up more RPM and begins to run rough ? It doesnt get the boat on plane like this, and you are kindalike "stuck" and slow speed (at least I could limp back to the boat ramp like this).
Since the previous owner had put in 4 new coils, plugs and cables my first suspicion was that maybe one of the main jets in in the carb(s) were clogged, so I took all of them apart and cleaned everything meticulously, but it didnt help a bit.
If you open the throttle valves manually (with the engine cover off) it will rev easily beyond 2500 RPM, but I guess this is not telling anything? but it gave me the idea that it must have something to do with the spark timing under load. I started to play with the maximum spark advancement screw?. I got it tuned to a point where the engine is running fine within a range until 3500 RPM ? enough to get the boat on plane and cruise around?. Basically I reduced maximum spark advancement drastically (as much as the adjustment screw would allow for) ?. Well, I can ride the boat now for a while like this? and took a little spin up the river, but it seems to be not very fuel economical now and once you go beyond 3500 RPM you have the same problems as before - this cannot be the solution either.
With my very limited knowledge I would say I may have something like a "weak spark"? So that it would only fire at lower RPM or not too much spark advance? What would you suggest I should do next? Replace the powerpack? I would hate to spend $$$ on spare parts that would turn out not to solve the problem... again, I would be grateful for any good advice, this kindalike sucks and I feel like an idiot.
Ah: I should probably mention that the compression is still good (just checked) and that the VRO pump was removed quite a while ago already running the engine on 1:50 premix
My Johnsone Outboard starts right up now and ran fine for the last months UNTIL suddenly inmidst of a tour on a long day ? it wouldnt take any more gas if you go beyond 2000 - 2500 RPM ? It is not "stuttering" as if the ignition would go on and off, it is just not picking up more RPM and begins to run rough ? It doesnt get the boat on plane like this, and you are kindalike "stuck" and slow speed (at least I could limp back to the boat ramp like this).
Since the previous owner had put in 4 new coils, plugs and cables my first suspicion was that maybe one of the main jets in in the carb(s) were clogged, so I took all of them apart and cleaned everything meticulously, but it didnt help a bit.
If you open the throttle valves manually (with the engine cover off) it will rev easily beyond 2500 RPM, but I guess this is not telling anything? but it gave me the idea that it must have something to do with the spark timing under load. I started to play with the maximum spark advancement screw?. I got it tuned to a point where the engine is running fine within a range until 3500 RPM ? enough to get the boat on plane and cruise around?. Basically I reduced maximum spark advancement drastically (as much as the adjustment screw would allow for) ?. Well, I can ride the boat now for a while like this? and took a little spin up the river, but it seems to be not very fuel economical now and once you go beyond 3500 RPM you have the same problems as before - this cannot be the solution either.
With my very limited knowledge I would say I may have something like a "weak spark"? So that it would only fire at lower RPM or not too much spark advance? What would you suggest I should do next? Replace the powerpack? I would hate to spend $$$ on spare parts that would turn out not to solve the problem... again, I would be grateful for any good advice, this kindalike sucks and I feel like an idiot.
Ah: I should probably mention that the compression is still good (just checked) and that the VRO pump was removed quite a while ago already running the engine on 1:50 premix