MAX RPMs - 2001 Johnson 115HP

[NelsonQ]

I'm trying to locate the service manual for my engine but with the faultering of OMC, they didn't produce one in 2001. Some say 2000 manual, some say use 2002 (another topic for another time)

However, reading another thread led me to the question, of what the max RPMs are for my engine (model J115VLSIC) I was told by an outboard mechanic that it was in the range of mid 5000. I'm running a 19P prop and can't get it above 5300RPMs at WOT (producing speeds of low to mid 40s in my 17 deck boat)

Does anyone know the max RPMs for that engine? I'm considering changing my prop in the spring and without knowing that info, I'm reluctant to play with the pitch. I don't have any confidence mid 5000s is the right # any more.

 

[iwombat]

Re: MAX RPMs - 2001 Johnson 115HP

You'll see my response in the other post, but you'll want to target at least 5.8k at WOT with today's gas. Any less and you're lugging the motor in ALL RPM RANGES - it'll run hotter and less efficient. If I can get within 200 rpms of that target in either direction I call it good enough.

 

[NelsonQ]

Re: MAX RPMs - 2001 Johnson 115HP

You'll see my response in the other post, but you'll want to target at least 5.8k at WOT with today's gas. Any less and you're lugging the motor in ALL RPM RANGES - it'll run hotter and less efficient. If I can get within 200 rpms of that target in either direction I call it good enough.

Thanks. I was thinking a 17P instead of my 19 anyway. I don't want to give up too much hole shot as I tube a fair bit but 17P sounds like it might be the right one to try.

 

[iwombat]

Re: MAX RPMs - 2001 Johnson 115HP

You'll actually get MORE hole shot with the 17p. That change should get you into 5600RPM or so.

 

[NelsonQ]

Re: MAX RPMs - 2001 Johnson 115HP

You'll actually get MORE hole shot with the 17p. That change should get you into 5600RPM or so.

Fantastic.... I was thinking in reverse that I'd get more RPMs, less hole shot..

I'm off to shop for a new prop......

Thanks for the info (in both posts) iwombat....

 

[iwombat]

Re: MAX RPMs - 2001 Johnson 115HP

Less prop is like going down a gear. It'll spin up faster (better hole-shot), but you'll pay a price in top speed.