Grady White with 200hp

[eula30]

Hi, I have a 20 footer Grady-White overnighter (Walk Around) with a 200hp Johnson, the propeller is 19 pitch. Any idea is that the right propeller for this set. Boat takes time to get on plane and max MPH is about 25. Any help I will really appreciated.<br />Thank you

 

[Solittle]

Re: Grady White with 200hp

What is the rpms at WOT? That will determine which prop you need.<br /><br />I suspect that you are not getting full power out of that motor. A 20'er with a 200 should jump out of the water & run a hell of a lot faster than 25.

 

[Boomyal]

Re: Grady White with 200hp

What is the rpm at wide open throttle and what is the maximum rpm stated for the 200 hp Johnson. Once you have matched the two, you are correctly proped.<br /><br />If you have the correct prop then you should start looking at trim tabs for the planing issue.

 

[eula30]

Re: Grady White with 200hp

I gat this boat about 3 weeks a go. So I don’t really know how fast it should go but the Rpm tach is not working wires is cut, I will fix it this week, One thing I notice, if I tilt the motor up wile in full throttle the boat will go on plane faster but after that it stays on 25 mph. I know the boat is really heavy but with a 200hp it should run about 35 to 40mph I think. I'm not really sure<br />Thank you

 

[gsbodine]

Re: Grady White with 200hp

Yeah, you gotta get that tach hooked up ASAP. That's one of the most important gauges on the boat. On that note, a speedometer on a boat isn't as good because they always seem to be wrong. Is 25 MPH what your speedometer is reading or is it a GPS figure? A GPS will give a far more accurate reading than many speedometers (especially speedos found on newly purchased used boats ).<br /><br />Post back with your WOT RPMS. Or better yet, if it seems like they're off, you may want to post your figures in the Johnson repair forum above. The guys in that forum are GREAT.

 

[Solittle]

Re: Grady White with 200hp

I wouldn't put much trust in the 25 mph reading unless obtained from a GPS.

 

[GradyBob]

Re: Grady White with 200hp

My 19 foot Grady 192 had a 150 Johnson, WOT around 5900 RPM w/ 13.75 X 19 SS prop obtained 43 MPH with full tank and 5 people in the boat. Repowered with a Yamaha F150, RPM 5,900 13.75 x 17 SS prop - GPS speed 43 MPH.<br /><br />I am with the rest of posts here, 1 is the speedo accurate, 2 get the tach looked at, and perhaps 3 is the prop aluminum or stainless? It can make some performance difference on your heavy boat.

 

[Osprey]

Re: Grady White with 200hp

Eula30,<br /><br />I bought a 95 Grady White 208 about three months ago. It has a 95 Yamaha 175. RPM's top out right at 5000. It cruises in calm open ocean conditions at about 20 to 23 knots at about 3800 to 4100 RPM's. Gas mileage is right at 2 MPG in mild conditions, 1.8 in chop. I will check the prop size and post.<br /><br />This boat was purchased knowing it was a bit of a project, but I have learned a bunch about these boats and had alot of fun in the process.<br /><br />If you would like to swap e-mails directly post your address to this thread and I will reply.<br /><br />PS - If your boat has plastic thru-hull fittings, inspect them very carefully for cracking and plan on replacing all of them as soon as possible.