George_Kasparyan
Cadet
- Joined
- Jul 14, 2023
- Messages
- 7
Hi all,
I recently purchased a 17ft 1990 Proline center console with a 1990 Johnson 90HP 2-Stroke motor. The motor came with the VRO pump removed and a fuel pump installed. The motor had no spark out of two of the four plugs but I quickly noticed it was missing one of the two CDL powerpacks. After replacing it, I got the spark with all four plugs. With a little love, I got the motor to start up. At times the idle would sound rough and at other times it would sound fine. I am running the motor off of a premixed 50:1 external 6 gallon tank. To get the motor started I had to continuously pump the primer ball, but once running, it would seem to pull fuel on its own. When manually giving the motor throttle in neutral, it never had a problem with bogging, but continued to run funky sometimes at idle. After a couple of days I tried to get the motor running again and it wouldn't start. I completely tore the carbs apart and thoroughly cleaned them (pretty dirty). After reinstalling them, the motor fired up, again needing to quickly pumping the primer ball. I put the boat in the water and it shift and ran fine at low speeds, although again sometimes struggling at idle. It ran well with a little throttle in gear (maybe 1500-2000 rpm), but once I got the motor up to what I would guess to be 2500rpm (tac doesn't work), the pitch changed and it began to make a bogging sound. The motor didn't decrease rpm or drop to idle, but rather continued at that same rpm but with a pitch change and a bogging sound and was unable to increase rpm and power. At times when slowing down and backing off the throttle, the motor would feel as though it got some gas and the boat would randomly suddenly accelerate as I brought the throttle back to idle. Again, it had no problem getting up to that 2500 rpm range, but that would change once it got there. I am going to replace the plugs anyways as one of the old ones cracked when taking them out for a compression test. After warming the motor, with all the spark plugs out and the throttle opened wide, I got approx 88-92psi out of all four cylinders. The motor spits water with a strong stream is getting good circulation. Why do you guys think this motor is bogging at 2500 rpm and won't reach higher rpm? Does this sound like a fuel problem, maybe the fuel pump? Maybe a clogged filter or old cracked lines with a leak so it is lacking fuel pressure? I opened the vent on the gas tank to make sure that wasn't starving it. I read that someone said to shoot a little carb clean or starter fluid right into the intake when giving it gas in gear to see if that would allow the motor to rev higher and possibly bypass the fuel issue for a split second. I think the diaphragm in the fuel may be damaged just based on the research I have done, but I am completely unsure. Could this be just from bad old spark plugs?
Thank You!!!
I recently purchased a 17ft 1990 Proline center console with a 1990 Johnson 90HP 2-Stroke motor. The motor came with the VRO pump removed and a fuel pump installed. The motor had no spark out of two of the four plugs but I quickly noticed it was missing one of the two CDL powerpacks. After replacing it, I got the spark with all four plugs. With a little love, I got the motor to start up. At times the idle would sound rough and at other times it would sound fine. I am running the motor off of a premixed 50:1 external 6 gallon tank. To get the motor started I had to continuously pump the primer ball, but once running, it would seem to pull fuel on its own. When manually giving the motor throttle in neutral, it never had a problem with bogging, but continued to run funky sometimes at idle. After a couple of days I tried to get the motor running again and it wouldn't start. I completely tore the carbs apart and thoroughly cleaned them (pretty dirty). After reinstalling them, the motor fired up, again needing to quickly pumping the primer ball. I put the boat in the water and it shift and ran fine at low speeds, although again sometimes struggling at idle. It ran well with a little throttle in gear (maybe 1500-2000 rpm), but once I got the motor up to what I would guess to be 2500rpm (tac doesn't work), the pitch changed and it began to make a bogging sound. The motor didn't decrease rpm or drop to idle, but rather continued at that same rpm but with a pitch change and a bogging sound and was unable to increase rpm and power. At times when slowing down and backing off the throttle, the motor would feel as though it got some gas and the boat would randomly suddenly accelerate as I brought the throttle back to idle. Again, it had no problem getting up to that 2500 rpm range, but that would change once it got there. I am going to replace the plugs anyways as one of the old ones cracked when taking them out for a compression test. After warming the motor, with all the spark plugs out and the throttle opened wide, I got approx 88-92psi out of all four cylinders. The motor spits water with a strong stream is getting good circulation. Why do you guys think this motor is bogging at 2500 rpm and won't reach higher rpm? Does this sound like a fuel problem, maybe the fuel pump? Maybe a clogged filter or old cracked lines with a leak so it is lacking fuel pressure? I opened the vent on the gas tank to make sure that wasn't starving it. I read that someone said to shoot a little carb clean or starter fluid right into the intake when giving it gas in gear to see if that would allow the motor to rev higher and possibly bypass the fuel issue for a split second. I think the diaphragm in the fuel may be damaged just based on the research I have done, but I am completely unsure. Could this be just from bad old spark plugs?
Thank You!!!
