Jack plate on ranger?

[Basshaker]

Took 98 r93 ranger I just bought for the first time. When going into the wind and current 1-3' the boat porpoised and the prop cavitated. Going down it ran great about 50 like it nothing. Looking for some advise on Jack plate position.

175hp evinrude model e175fpxssr
CMC jack plate ml-65

Picture of position... sorry for the side way pick

[turfy49431]

Need to know propshaft to pad measurement to really gve u any info

[gonnabe]

Start by lowering the jack plate down to where you can only lower it another inch and it should be close. You are way to high.

[crank68]

Need to know propshaft to pad measurement to really gve u any info

This ^^^

[larryhyco]

Need to know propshaft to pad measurement to really gve u any info

Need to know this measurement. I think mine is 3 1/4 inches below pad

[Basshaker]

I will get this measurement today.

[Basshaker]

So I believe 3.5 ish need a better surface to measure again.

Ran it again today wasn't quite as rough but ran great. I am wondering if I had it trimmed down all the way.

[larryhyco]

Did you check RPMs, speed and water pressure? We need those numbers

[Basshaker]

No educate me

[Javelin387]

What is that huge crack on the transom? Just above the transom cap? Might just be a stress crack. Also, I agree, if the plate is already at the highest setting, it will most likely need to come down.

[Basshaker]

I need to get back some place on level ground to measure. That is silicone caulk someone put it around a the plastic trim piece. Transom is solid had the boat inspected.

[MikeTTI]

The condition of your prop could also factor in to the problem.

[Ky 520c]

Ran a r91 for years, everyone is right tho we need to know you PTP. But judging from seeing the bottom of engine bracket and the fact your jack is ran to the top your way to high.

[Basshaker]

I will get it on Friday. Someone pointed out the motor is a 25" shaft, I expect that is why it is all the way up. Based on a not perfectly level measurement it is 3.5".

Some one earlier asked about rpms and water pressure... I can read rpm gauge but how would I know water pressure?

[huntertn]

To know the water pressure you need to have a water pressure gauge in the dash. If you don't have one already I think that they are a good investment.

[Basshaker]

So I really should have an extra prop, looking for recommendations

Aluminum 14.25 x 21
3.5 prop to pad
50-52 mph GPS at 5000rpm

I really haven't run it wot

Given the fact the motor is 25" shaft I won't be able to raise higher than 3.5 ppt

Runs great with this prop motor sounds real nice. Not really worried about more speed but really should have extra so I might as well kick around options.

Any thoughts are appreciated

[Basshaker]

I see mentions of a raker 14.5 x 24, good option?

[larryhyco]

My R91 is 3-1/4 below pad

[jc2bg]

I see mentions of a raker 14.5 x 24, good option?

The (original) Raker was designed for the engine you have, so yes, it is a good option. But without knowing how many RPMs you run at wot with your current prop, it’s more difficult to determine whether the 24 pitch would work well. I would say, try a 22 pitch in the Raker first, especially given that top speed isn’t your primary focus.

[Basshaker]

Thanks for the feed back, I will likely go out this evening and will run wot.

Nubbie question a pitch number goes up does that increase rpm or lower... or what is the correlation?