Prop Help Needed Newbe- Johnson 200GT

[wkendwarrior]

I have spent a few days now searching for good advice on the correct prop for our newly acquired 1990 Stratos Fish & Ski. It has a 1990 Johnson 200 GT on the back. Currently it has a incorrect 4 blade stainless prop on it that is robbing it of all its power. I believe the prop is something like 14 3/4 x 23. I have searched all over, and cannot seem to find the correct prop for this boat. Too many options available.

This boat will be used for more for recreational purposes. Power to pull a skier is more important than flat out top end speed.

Can someone please recommend the proper prop for this thing? Any help is greatly appreciated. Would love advice on either 3 blade or 4 blade props.

Thanks guys.

 

[Silvertip]

Re: Prop Help Needed Newbe- Johnson 200GT

How do you know its the wrong prop? You know you have a wrong prop because the rpm at wide open throttle with an average load is above or below the rpm band the manufacturer recommends for the engine. To understand that statement, you make some wide open throttle runs with an average load. Note the maximum rpm. If its lower then the recommended you have too much pitch and if its higher (engine over reving) then there is too little pitch. You haven't given us those numbers. Unless someone has an identical setup we can't be of much help.

 

[steelespike]

Re: Prop Help Needed Newbe- Johnson 200GT

As suggested give us the boat size & details,prop size off the prop,then the present max rpm and speed,by gps if possible.Tell us in detail your performance issues,what you want to accomplish.This is the only way to know what you have and what you may need.

 

[wkendwarrior]

Re: Prop Help Needed Newbe- Johnson 200GT

Sorry guys. Boat is a 1990 Stratos 289 FS with Johnson 200GT
Current Specs with average load and full fuel tanks:
Boat Length - 19.5 feet
Prop - 4 blade stainless Stiletto 14 3/4 x 23
Top Speed WOT 42 mph
Top RPM WOT 4200
Recommended RPM 6200

It runs good with good compression numbers, but seems underpowered. Takes it a while to plain off even using trim, and top speed seems low. With 200hp, I would imagine this thing should jump right up and fly.

It will be used for pulling a single skier. I am just looking for a good recommendation on a OEM size prop or similar. If it does not work out, I will work on making adjustments.

My problem is that I see several prop options online. What is the difference between a 15 x 17 or a 14.5 x 19 prop? Etc.

Thanks guys.

 

[Dhadley]

Re: Prop Help Needed Newbe- Johnson 200GT

There was no prop supplied with that motor from the factory if that's what you're looking for. If we're setting this up for skiing, we'll go one direction. If the main focus is recreational boating and some skiing then we'll go another.

Next question - do you have a jackplate?

Next - Stiletto doesn't make a 14 3/4 4 blade. Could it possibly be a 13 3/4" diameter?

 

[wkendwarrior]

Re: Prop Help Needed Newbe- Johnson 200GT

Lets say recreational, with some skiing. But buying more than one prop is an option too.

Nope, no jackplate on it.

 

[Dhadley]

Re: Prop Help Needed Newbe- Johnson 200GT

Great, now lets get the number off of the Stiletto so we can see where we're at now. I'd bet that a 14 1/4 x 19 Stiletto will probably be where we need to be, maybe a 21.....

 

[wkendwarrior]

Re: Prop Help Needed Newbe- Johnson 200GT

We are eager to get this thing on the water. Would you go with the 14 1/4 - 19 in an aluminum 3 blade? Being so new to this, we just want to get something on it quickly, for not alot of money. We can work our way up to more expensive props once we get this thing figured out.

My brother is going to get me the numbers off the prop in the morning.

Thanks for your help.

 

[wkendwarrior]

Re: Prop Help Needed Newbe- Johnson 200GT

You were indeed correct. The current prop is a 13 3/4 x 23 Stiletto.

Thanks for your help.

 

[Dhadley]

Re: Prop Help Needed Newbe- Johnson 200GT

What kind of rpm will it turn with the Stiletto? That's not a bad prop at all. If the motor is mounted all the way down it may help to raise the motor. Even though those are an OT style prop they still like height.

 

[wkendwarrior]

Re: Prop Help Needed Newbe- Johnson 200GT

It will not go over 4200 rpm with the current prop. The engine runs great with great compression across all cylinders. That is what makes us think changing the prop will work better and get the rpm's up.

This prop change was recommended by a dealer who worked on the boat.

 

[Dhadley]

Re: Prop Help Needed Newbe- Johnson 200GT

Is the motor mounted all the way down?

 

[wkendwarrior]

Re: Prop Help Needed Newbe- Johnson 200GT

The motor looks like it only mounts on in one position. Any lower and it will not tilt. And looking at the transom, it looks like you cannot raise it up at all.