2003 Jonsuki F140 RPM Question

[toddbrown]

Does anyone know what RPM I should be able to turn on a 2003 Johnson F140? The motor is mounted on a 2003 Sea Hunt 202 CC.

Thanks

[Baytro23]

The correct wot is 6000 rpm's for that motor. The rev limiter kicks in at 6200. I had a 2003 Johnzuki 140 on a 2004 SeaPro SV-2100cc. My best economy was between 4000-4500 rpm's.

[toddbrown]

I am only able to get 5600 rpm currently. I assume it is a prop issue. Do you have any thoughts or suggestions?

[Baytro23]

I believe you are lugging the motor slightly. Probably over propped. What prop are you running? Try about 2" less pitch. My boat came with a 17" pitch 3 blade aluminum and I was able to easily reach the rev limiter even with a normal load. The dealer exchanged it for a 19" and I could barely reach the limiter with a very light load and with a regular load the wot was 6000rpm's (perfect).

[bluesbrother]

I believe you are lugging the motor slightly. Probably over propped. What prop are you running? Try about 2" less pitch. My boat came with a 17" pitch 3 blade aluminum and I was able to easily reach the rev limiter even with a normal load. The dealer exchanged it for a 19" and I could barely reach the limiter with a very light load and with a regular load the wot was 6000rpm's (perfect).

Mine (115) does 5600 RPM with 16X19 alloy prop.

[paul h]

For the suzuki df-140, wot should be 6000-6500rpm. I've run two props on my df-140, a suzuki 14X19 3 blade which I can only get 5700 rpm out of, and a solas 13 3/4 X 17 4 blade that I can get 6050 fps out of. Economy on both props is the same, but I run the 4 blade solas as it puts less load on the motor. You might find the 3 blade 14X17 is not enough prop, so try the Solas, especially as they are much less expensive than the suzuki props.

[CudjoeDon]

Not enough info. You get 5700RPM, but is that full-load, light-load, or between? Is that trimmed up just before it loses grip? What speed? What are you trying to improve -- top speed, acceleration because of shallow water, MPG at cruise? Are you happy with how the prop performs now with regards to grip, handling, acceleration and so on?

And most importantly -- what prop do you have?

I have several props for sale because I'm still searching for the best all-around prop for my boat -- since it is a single-engine cat my case is trickier:

Solas Amita4 13.75 x 17pitch 4-blade aluminum

Power Tech SF115PTR4R15P 13.75x15pitch 4-blade stainless

Power Tech SF115PFO4R18P 14x16pitch 4-blade stainless [re-pitched from 18 to 16 and about half the cupping removed]

Best prop so far is a pretty basic Evinrude 14x17pitch 3-blade aluminum, but I have a Power Tech 3-blade stainless 14x16pitch on order from Prop Gods.

CudjoeDon

[Drailey]

6200 max! That's where I have my twins proped for!, Any more and the limiter will kick in. Also, thats what the owners manuel says.