Solas amita3

airhammer · Sep 2, 2013

Hi everyone I'm new here, this is my first post, although I have done a lot of reading here.

I have a Lowe 1648 with a 30 Johnson, both 2000 models. Wanting a little better performance I bought a tiny tach and

She was only turning 4950 at wot , motor trimmed up to 4th hole. About 24 mph , loaded me and my son trolling motor,

Cooler, all gear. This is the way it always runs. Using the 200 rpms per inch rule, I bought a solara 11 pich prop. Well it

runs

great lots of response, but too much rpms, about 5850. I think if I held it it would rev a little more. I would love it if I

could go to a 13 or 14 pitch, but I don't understand why I gained so much rpms. Could it be a lighter better design in

The solas, causing the rpm gain. I had the stock 13 pitch prop on. Motor is tuned and runs great. I am waiting for

A reply from solar a, but thought I would ask here.

Johny25 · Sep 2, 2013

Ok first off do you mean Solas? I have never heard of Solara........

There could be a few reasons your RPM's went higher than expected, from prop design (like thinner blade design or less/more cupping etc), different number of blades, material of the new prop (was your old prop aluminum and you bought an SS?), old prop damaged and new one wasn't? There are a lot of variables here and the 200rpm increase or decrease is just a rule of thumb to star with. Every prop manufacturer makes props in a little different way so when you switch manufacturer its becomes a game of roulette a little bit unfortunately. Although if you bought a prop that was made out of same material, number of blades and your old one wasn't damaged in any way I would not expect 1000rpm increase by going down 2" in pitch.

You have the 2 cylinder model right? I don't think they were making the triples in 2000 anymore........

Gotem · Sep 2, 2013

You may want to use the original prop. I am sure the noise is less then when the outboard hits the higher rpms. Just a thought.

airhammer · Sep 2, 2013

Sorry, yes it is a Solas Both old and new props are aluminum and 3 blades. Old prop doesn't appear to be in that bad of shape. Worn paint on edges and maybe one nick. I did notice new prop felt lighter. I want all I can get out of her. I want to be able to turn up to about 5500.

manufacture recommends 5200 to 5800. I still can't get over this 1000 rpm gain. And yes it is a 2 stroke. I have looked at stock prop and yes some nicks more like chips of paint worn off. Just trying to figure where to go now that I know what the new prop does. Really want a new prop on and use old one for a spare. The problem is once you put a new prop in the water it's nonreturnable.

Johny25 · Sep 2, 2013

What I meant by 2 cylinder and not being a triple.....was how many cylinders it had. They made a 3 cylinder for a few years around that time but I do not think the 30hp ever came in a 3 cylinder (aka a triple)

Well basically I run the same exact motor although mine is an 88' and I am running a 10X14 Solas stainless. they made the 30hp with that 31.8 ci block for many years. I am not saying you can run a 14 pitch because your boat and setup is not the same. I had a stock 13 pitch on mine that ran right around 5500rpm and went to stainless going up 1" in pitch and lost only about 50-100rpms. A lot of people will argue that stainless is harder to turn because of the weight but I will argue against this until the day I die. The performance upgrade running stainless is very noticeable as the blade design is typically a lot better due to the material being able to be manipulated into a better more efficient design and thinner blades.

The 1000rpm gain is confusing though. And like you said once it hits the water you are screwed :x There is no true science to getting the prop right. Making an educated guess to start and then trial and error is about as good as you can do unfortunately.

You didn't post a speed number on the 11pitch but running the numbers off your stock 13 assuming you have a 13:28 (2.15:1) gear ratio puts you at 15% slip which was not bad.

airhammer · Sep 2, 2013

It is a 2 cylinder. The speed with the 11 was about the same. Only difference was I had the live well with about ten gallons of water. It will run just as fast with the 11 as the old stock 13 and has a heck lot more acceleration I think maybe the change in manufacture of props may be the big difference. I have been thinking of a 14 stainless, but would really like to understand what change I can expect with rpms. I feel the new prop is in good shape so really what change in rpms should I expect? Maybe I will hear something from a tech a solas. If I only lost 150 or 200 rpms I could probably push a 13 or 14 aluminum at 5200 to 5400. I am not going to jump out and buy a 14 stainless just yet, I am more leaning on a 13 aluminum . I understand the trial and error, that's why I am playing with a cheap prop.