02-16-2020 06:46 - edited 02-16-2020 06:47
New spring and the ultra hi-flow screens like you mentioned.
"There is never just one thing wrong with a boat";
-- Travis McGee, main character in a book series by John D. McDonald
The factory recommends that a properly trained technician service your Johnson or Evinrude outboard motor. Should you elect to perform repairs yourself, use caution, common sense, and observe safety procedures in the vicinity of flammable liquids, around moving parts, near high-temperature components, and working with electrical or ignition systems.
The information offered here is only general in nature and should not be construed as complete factory approved procedures, techniques, or specifications. Always use the proper service manual for your motor, up-to-date service literature, the correct tools, and have an understanding of how to proceed with troubleshooting and repair methods. If you are unsure or uncomfortable with a procedure, a situation, or a technique, enlist the services of a factory trained technician.
02-16-2020 08:57 - edited 02-16-2020 09:00
Few other questions, I’m running like 5100-5200 wide open and trimmed up, I’m afraid I’m lugging the motor, I’m considering going to a lower pitch prop, and a four blade for better hook up, my question is, should I be conserved about being that low on the rpm?
You are lugging that engine and you should be concerned. You need to get another 600 rpm. If you go to a 4 blade you will get better hookup but you will loose top end. If you goto a 4 blade of the same pitch as your current prop you will loose rpm. You need to go to a prop with 4 inches less pitch than you have now. If you go 4 blade maybe 5 inches
You will get about 150 rpm per inch of pitch. So if you were to go from a 19 to a 17 3 blade you would gain 300 rpm going to a 17 4 blade you would gain 200 rpm which is to low. The optimal rpm range is 5500 - 6000rpm I would target least 5600 Fully loaded.
02-16-2020 09:56 - edited 02-16-2020 10:00
Is it normal to have to put a 15-16 in pitch prop on a 300 horse?
The other option is the motor isn’t putting out enough power to spin the prop. I just got this boat late this past summer and just don’t know enough about what to expect out of the motor?
Propping a rig has nothing to due with the horsepower of the engine. It has to do with the complete setup. It possible you have power issues, I couldn't say. You have way too much slip in my opinion. I use both a 3 and 4 blade prop on my rig, and the slip is less than 10% with both of them. Does your current prop have rubber or TBX hub?
Have you verified that you are running on all 6 cylinders?