1989 150xp Stalling At High RPM

[emdsapmgr]

Re: 1989 150xp Stalling At High RPM

The power pack is only one of the ignition components on that engine. The 6 coils are usually pretty reliable, but you also have a stator and a timer base which can cause spark/ignition problems. A sluggish engine may not be running on all 6 cyls. The engine will seem to run just fine on 4 or 5 cyls when on the trailer. Sounds great, but hard to audibly tell if they all fire when not under load. That's why it's good to know if all 6 plugs are contributing spark/power when the engine is fully warmed up. When you dunk it in the lake and shift into forward, you need all 6 firing to make proper power. Running on the hose should not be a problem. Should run all day on the hose, but the cold city well water may cause it to run a few degrees colder-not a problem.

 

[ricklow]

Re: 1989 150xp Stalling At High RPM

The power pack is only one of the ignition components on that engine. The 6 coils are usually pretty reliable, but you also have a stator and a timer base which can cause spark/ignition problems. A sluggish engine may not be running on all 6 cyls. The engine will seem to run just fine on 4 or 5 cyls when on the trailer. Sounds great, but hard to audibly tell if they all fire when not under load. That's why it's good to know if all 6 plugs are contributing spark/power when the engine is fully warmed up. When you dunk it in the lake and shift into forward, you need all 6 firing to make proper power. Running on the hose should not be a problem. Should run all day on the hose, but the cold city well water may cause it to run a few degrees colder-not a problem.

I connected the motor to muff for water supply. Lake is a long drive. I let it run in drive for about 15 minutes at about one third throttle. Temps held around 140. I then carefully pulled one plug at a time. All demonstrated a spark as I pulled them off, some more spark than others, by grounding to the pliers I used. But the impact on the sound of the motor varied greatly. The number 1 plug did not seem to drop the sound at all even though there was a spark to the pliers. The number 2 plug had the most significant impact on the rpms of the motor. Numbers 3,4,5,6 had a slight but noticeable impact on the rpms. Do I learn anything from this? What would be recommendations from what I know? Might miss the sauger this year.

 

[emdsapmgr]

Re: 1989 150xp Stalling At High RPM

For some reason the #1 plug is suspect. The plug itself could be bad or it may not be getting any fuel. After running, did you pull the plug out and compare it to the others? Was it wetter or dryer than the others? If the carb is not providing fuel through that barrel, that plug won't fire. Worse, if it's not getting fuel, it's also not getting any lubricating oil-a cylinder killer for sure. I think there is a problem if all plugs don't demonstrate the same strong, blue spark.

 

[ricklow]

Re: 1989 150xp Stalling At High RPM

For some reason the #1 plug is suspect. The plug itself could be bad or it may not be getting any fuel. After running, did you pull the plug out and compare it to the others? Was it wetter or dryer than the others? If the carb is not providing fuel through that barrel, that plug won't fire. Worse, if it's not getting fuel, it's also not getting any lubricating oil-a cylinder killer for sure. I think there is a problem if all plugs don't demonstrate the same strong, blue spark.

Have been told I should clean carbs which I plan on doing today. Is there something else you would recommend ?

 

[ricklow]

Re: 1989 150xp Stalling At High RPM

Was told to clean the carbs. Took them off. Found that the small nozzle on the top of the middle carb that has a 1/16 hose going to the primer solenoid had been JB welded, or tried to. The nozzle can out as I was taking the hose off. How would you reattach this nozzle. If is like the brass theading, if that is how it is connected, can our with the nozzle. The aluminum hole that it goes in is smooth without any threading. Ever heard of this?

 

[emdsapmgr]

Re: 1989 150xp Stalling At High RPM

That brass hose barb is for the small fuel primer hose (the choke.) They may simply be a pressed fit at the factory. Since there is no stress on that hose barb, you might be able to use some red Loctite to re-secure it. I would not run that carb if the hose barb is missing, it could lean out that carb.