New to me boat set up ranger r70

[Dylanallen512]

Hey guys in need of some assistance, recently bought a new to me 97 ranger r70(first glass boat) that was repowered by previous owner with a brand new 135ho etec. the boat seems slow to me here’s the information I have maybe someone can chime in
pad to prop 6 1/2” (I have 2 bolt holes I can move up still)
14x23 aluminum prop
42mph at 4070rpm

I know the rpm is supposed to be up at 5800 my question is what are guys running for prop to pad height for the r70? I would like to get the height figured out before I start trying different props, thanks in advanced!

[ChooChooSnakeMan]

I don't know that hull but for glass boats 6 1/2" pad to prop is way too much. You have in my opinion way to much of your lower unit in the water, hence a lot of drag. Most glass boats in my experience (not go-fast hulls) are good around 3 to 3 1/2 inches. I'd start at 3 1/2" and see what you max rpms are. Don't fall into the trap of many first time glass owners and go trim happy. Trim up watching your speed and rpm. As soon as you start seeing rpm go up but speed doesn't or even speed comes down then bump the trim down and that is your best trim setting for that engine height. See what your max rpms are at that trim. If at 3 1/2" you are low on rpm and your water pressure is good then move up to 3" and try that. It takes time to dial one in. When you get you best prop to pad height that still allows safe water pressure you will then know if you are under or over-propped. I hope this helps. Remember if you see a need to change pitch that one inch of pitch usually equals a rpm change of around 200. I'd also consider ditching the aluminum prop when you can budget for it. Aluminum flexes easily and isn't durable. A stainless prop of even the same pitch as an aluminum will outperform the aluminum prop because it doesn't flex and being stronger can have thinner blades.

[Dylanallen512]

Thanks man, gotta try moving the motor up 2 holes and see where that gets me, planned on going to a raker once I get the height figured out might even bite the bullet and throw a jack plate on it.I appreciate your advice!

[Tom Rollins]

3" to 3 1/2" will be to high with out a jack plate. 4" +/- will be a good starting point. You probably need to drop to a 21" prop.

[KandKKustomz]

put a jackplate on it you will be glad you did w a 135 etec on that boat theres min 10 mph plus sitting there provided set up correctly.. those r boats have fast hulls. 6 inch plate set 3.5 to start ( up from there) and a fury 3 22 or 23 you will be grinning ear to ear

[Dylanallen512]

Thanks for all your input guys greatly appreciated!

[nighthawk]

I had a 95 with a 115 Mercury. Top speed was 48 with a stainless quicksilver prop (pitch, I think).
I think you should be in the 52-53 mph range if running right and setup properly.

[Dylanallen512]

Now that I’ll be adding a plate here soon, the boat does have a single power pole with the sand which style bracket, would I have to change the mount for the pole? Or is there a certain order to install ex: bracket-plate-motor or plate-bracket-motor?

[Dylanallen512]

Just wanted to post an update moved The motor up 2 holes and got the pad to prop to 5” water tested boat and it seemed to perform a lot better 46mph at 4300rpm calculated slip at 11% a lot less splash coming off of back of boat aswell. So I think now down sizing a prop will get me close to where I want to be. Thanks again to all the input

[caddelma]

Motor is not a 25 inch shaft is it?

[Dylanallen512]

Nope. 20”

[zaprod71]

I have totally different boat, but I run a 20" Viper prop and a 21" Solas HR Titan. I think both are 14 5/8" diameter. Solas props are good choices for experimenting, IMO, good props and very afforadable.

[Astroglass165v]

Man with your rpms, I'm thinking your gonna need at minimum at 21p, maybe even a 19p prop

You might verify your tach is setup right. I would imagine it would have different tach settings on the back. Others could help tell you which you actually need. Maybe a bad tach too.

Mine was bad when I got it. Said I was running a 19p 5200 rpm at 51mph, which equated to negative slip for me... changed the tach I was actually turning 6200 rpm...

[KandKKustomz]

Now that I’ll be adding a plate here soon, the boat does have a single power pole with the sand which style bracket, would I have to change the mount for the pole? Or is there a certain order to install ex: bracket-plate-motor or plate-bracket-motor?

you can keep the sandwich mount bracket go between transom and jackplate not motor and jackplate. However i would suggest going to a jackplate bracket , will make adding a second pole down the road fast and easy.

[dblume]

My old one a 2000 R73 with 125 merchant would do 53 and 48-50 loaded

[KandKKustomz]

Agreed I expect loaded right, set up right, he should be 52-54

[Alex from GA]

Max rpm for that engine is 6000. You have to find a way to get them near there. Get a hand held tach that takes a piece of silver tape on the flywheel and tie the boat to the dock. This is the one I have from Amazon. FITNATE 20713A Digital Tachometer RPM Meter, Non Contact Rotation Photo, 2.5~99,999 RPM Accuracy with Batteries Included, 4 Packs of Reflective Tape, Revision Instruction

[Dylanallen512]

I found a 20x14 raker, I’ll be throwing that on today but I’m not sure when I’m gonna be able to test with the north east being covered in snow and all waterways iced up ready to hook up and head south

[Dylanallen512]

Hy guys just wanted to give an update I I installed a 5.5 cmc manual plate was able to run today. Slight chop with light wind I’m running 60.1mph 5500rpm 20x14 raker 3.75 prop to pad around 20 psi on water pressure tourney load with 2 guys

[Astroglass165v]

Man you gained some speed! But your rpms are still too low.
From 46 to 60 is awesome!