Johnson 200hp Proppeller

[eula30]

Hi , I have an 1976 200hp Johnson with a 1976 21 footer Grady-Whites WA, The propeller on the motor is a Aluminum 15 1/2 X 19 I'm doing 45 knots with full load very happy with. I just bough a Stainless Steal Power tech 15 ¼ X 17 any Idea with one should be better…<br />Thank you

 

[angus63]

Re: Johnson 200hp Proppeller

Use the one that results in a WOT of 5500 RPM minimum with an average load. If the 17 pitch results in a WOT RPM of greater than 5800, than stick with the 19 pitch. You may want to hold on to the 17 for skiing, tubing, or a 6 man fishing trip.

 

[eula30]

Re: Johnson 200hp Proppeller

Hi there, thanks for you quick reply. I don't have RPM Gauge working on this boat, I only go by Knots, I have been working on the RPM with out any look, but out of all the time that I used the boat 95 % it is with 4 to 5 people, 30 gallons live well full and running, 65 gallons fuel tank Full, extra motor (Kicker), all the fishing tackle etc... To me the boat is really loaded and works extremely well in calm seas and ruff seas also. If I used the 17 pitch will the boat lose speed at WOT? Thanks for any help…<br />Thank you

 

[angus63]

Re: Johnson 200hp Proppeller

Drop in pitch (19 to 17) does not mean a drop in speed. The most important thing for the health and longevity of your motor is being properly propped for your most common load condition. First step is to hook up an accurate Tach and give us the WOT RPM as it is setup now, and then we can suggest prop and setup changes. Without knowing the present RPM, we can't suggest where to go from here and what affects the change in pitch might have. If you use the search feature with keyword "tach" at the top of the page, there are many posts with links to find tachs online.<br />Post back when you have the numbers and they'll be many who will be happy to help.

 

[walleyehed]

Re: Johnson 200hp Proppeller

Max RPM is 5750 on that engine.....if you get 5800, all the better. I'd take the 17" SS in a heartbeat..5500 isn't enough R's for that engine.<br />As for which will give the 5800, I think the 17 will be the closest.

 

[nelsonk11]

Re: Johnson 200hp Proppeller

Is anybody concerned about running a '76 engine at 5500 to 5800 rpm? I have a 85 Grady with a 90 Johnson 200 hp, and I won't go near that end of the range. Am I too cautious?

 

[moderator1]

Re: Johnson 200hp Proppeller

Yes, you are too cautious... <br />Understanding what is happening inside the 2-stroke is a different ball of wax compared to a, well, let's say and auto engine...<br />For the engine to maintain it's greatest power AND longevity, you must prop for the TOP of the recommended RPM range. 5500 would be minumum on your 200..in the lower 5's, you'd be lugging it.<br />I would strongly suggest you spend some time at or above 5500, and by saying this, I mean it must have the prop that will allow 5600-5800RPM.

 

[nelsonk11]

Re: Johnson 200hp Proppeller

I currently have a 15 1/2 x 15 michigan prop on this 200hp. If I push the throttle to full open, I'm sure I'll go well over 6000 rpm. My problem is that it runs perfectly above 1000 rpm, but when I'm coming up river to the dock (1000 rpm), it will stall (tuff to dock). If I go to a higher pitch to bring down the high end rpm, I'll make the docking proble even worse at the low end won't I?<br />Nelson

 

[moderator1]

Re: Johnson 200hp Proppeller

I would suggest a manual and then do a linkage sync. If that doesn't work, you may need to pull carbs and inspect and clean the Idle circutry.

 

[Cricket Too]

Re: Johnson 200hp Proppeller

nelson....What RPM does your 200 run at WOT now with the 15 pitch? You have to look at the prop like a gear in your car's transmission, if you were driving around at 20mph with the car in 4th gear you'd be lugging it badly and beating on the engine, and if you were running your car at 40mph in 1st gear you'd be running it too high. If you are stalling when docking it doesn't have anything to do with the prop, making the WOT RPM correct won't affect your docking.<br /><br />eula...I have a pair of 2000 200hp Johnson's on the back of my boat, with 17 pitch props, they both run at 5800 WOT and run perfect. On offshore trips they run between 5000 and WOT all day long without missing a beat, speed is about 45mph on a 25' Hydra Sport W/A, total setup is about 6000lbs, and usually have at least 4 or 5 guys on board all at 165-190, so about another 900 and then all the gear, so at least 7,000lbs fully fueled. I'd do what angus suggested and get a tach and see where your at, but I agree with walleyehed that the 17's will probably be your best bet.

 

[nelsonk11]

Re: Johnson 200hp Proppeller

Ok, bear with me here. If my low idle is 1000 rpm, and the speed associated with that is x using a 15 pitch, and I then change to a 17 pitch my speed will then be y @1000 rpm (it probably won't change at the low end)--wouldn't you expect y to be faster than x? In which case docking gets even harder.

 

[walleyehed]

Re: Johnson 200hp Proppeller

First, you have an Idle issue...you should be Idling around 650. If set for proper Idle, the 17 will be slower than the 15 @ 1000RPM.<br />If you don't have a manual, get one and perform a link-n-sync and see if that helps...you may have some Idle circut carb issues too...they may need a go-through.

 

[nelsonk11]

Re: Johnson 200hp Proppeller

I agree the idle is too high. I'll have to check the items listed to try to correct that. The other issue of prop pitch I don't agree with. If the definition of pitch is the theoretical forward movement in inches for a revolution, then for the same number of revs the 17 would move further than a 15 and thus faster--no? This would be the same effect as comparing 4th gear on a car with 1st gear. I still think if I go up to a 17 the effect will be faster movement for a given rpm, and consequently a faster approach to the dock which is a problem.