Nissan 30HP 4-stroke @ WOT Low RPMs

[glogsdon1]

Just purchased a Crestliner with this 2004 Nissan 30HP 4-stroke. At WOT the most I can get is about 4500 RPM. The manual states the range should be 5250 to 6250 RPM. It also states that with the long shaft version it would come with a 9.9x11 prop. Mine has a 9.9x10 which as I understand should already be giving me more RPMs. Any suggestions?

 

[hwsiii]

Re: Nissan 30HP 4-stroke @ WOT Low RPMs

How far is your antiventilation plate below the keel.


H

 

[Wee Hooker]

Re: Nissan 30HP 4-stroke @ WOT Low RPMs

FWIW, I have this same motor in the 09' flavor. Mine came factory with a Solas 9.9x10P prop as well. The motor is mounted (by dealer) 2" too low, still achieved 6120RPM /30 mph on it's break in run. I have had problems getting to full RPM range only when I had the ( 800# , 16' aluminum Deep V) at max rated weight capacity during a boat camping trip.
If your crestliner is a HEAVy boat, you may need less pitch or more motor.

FWIW, I recently bought a 11P Rascal prop and plan to raise the motor up soon.

 

[glogsdon1]

Re: Nissan 30HP 4-stroke @ WOT Low RPMs

My anti-ventilation plate is about an inch below the keel.

 

[hwsiii]

Re: Nissan 30HP 4-stroke @ WOT Low RPMs

Don, if it was me I would try raising it up 3/4", but be sure and add a filler between the top of the transom and the motor plate, so it doesn't jump off the boat.

H

 

[Wee Hooker]

Re: Nissan 30HP 4-stroke @ WOT Low RPMs

FWIW, I finally got off my can and raised my 30 Nissan a couple of holes today. I've got the Acav plate within 1/8" or so of the keel now. Looking forward to sea trials latter this weekend!

p.s. I used a bottle jack with a 2x4 across the bottom of the transom bracket to lift the motor. Worked well! Just:
1) loosen all 4 mounting bolts 2 clamps.
2) take up slight tension on jack.
3) Remove 2 upper mounting bracket bolts completely from bracket.
4) Jack motor up so it slides up transom. ( Watch to make sure clamps don't hang anywhere)
5)align and re install upper bracket bolts
6) Silicone seal all bolts at transom.
7) Re tighten everything.
8) Remove jack

Took less than an hour with setup and clean up.
hth

 

[hwsiii]

Re: Nissan 30HP 4-stroke @ WOT Low RPMs

Don, that is just great get back with us on WOT RPM and speed so we an run some numbers to see what you might possibly want to do.


H

 

[glogsdon1]

Re: Nissan 30HP 4-stroke @ WOT Low RPMs

I installed a 9.9x9 prop. I can now get up to 5600RPM with two people on board when trimmed out. That seems to be in the ballpark now. Thoughts?

 

[hwsiii]

Re: Nissan 30HP 4-stroke @ WOT Low RPMs

That appears to be working fine for you, you seem to be in good shape.


H