Evinrude 200/ 19 ft glasply-WOT=64-6500

[benpsg]

I have a 19 ft glas-ply, 200 hp evinrude 2 stroke, on a bracket. the prop on there is a 15x17 alum. Running wide open the RPMs are in the 6450 range. I think thats too high, but I dont know for sure. the boat performs great, jumps right up, does aallllmost 50 mph. I want to upgrade to a stainless prop, but because of where i live, going to a shop, borrowing props, etc, is not feasable. im on a remote island in alaska, so its pretty much, do my homework, buy a prop, and live with it.
i want to A, get any fuel economy i can get, B, going faster is always positive, and C, lower my rpms down to...? i dont know.

so a couple questions. do i have to stay at the same diameter? would i notice a difference in fuel consumption by dropping to a 14.5 or 14.75?

assuming i got a 14.75x19 in stainless, what would be different between a 3 or a 4 blade?

finally, WHAT AM I NOT AWARE OF? Its easy to ask questions, but i know theres things i dont know about, and i welcome any and all advice. thanks for any help.

 

[HighTrim]

Re: Evinrude 200/ 19 ft glasply-WOT=64-6500

Your rpm range at WOT should probably be in the 5800 rpm range, so I do think you are a tad high. Someone correct me if im wrong here. The goal in prop selection is to determine what propeller style and size will maximize performance for your boat, while allowing your engine to operate in the recommended RPM range. The correct propeller will prevent the engine from over-revving, yet allow it to reach the minimum RPM where maximum horsepower is produced. Increasing the pitch increment by 1" will result in approximately a 200 RPM drop, so you will probably need to increase your pitch by about 3", IF I was correct in the rpm range of 5800. Switching from an uncupped to a cupped propeller will also reduce your RPM. The cupped propeller of the same pitch and diameter will typically reduce your RPM by approximately 200.

Once your wide open throttle RPM falls within the recommended range of the engine manufacturer, you have a propeller that is suited correctly for your boat with respect to RPM. If you use your boat for fishing, cruising and skiing, one prop probably won't do all three things equally well. It is best in circumstances like this to have two propellers. One to accommodate one set of circumstances and the other to perform best under the different load. It could, in fact, be that more than one propeller would be suitable for your boat and motor combination depending on your usage. It is imperative, however, that the wide open throttle RPM fall within the range specified by your engine manufacturer

 

[steelespike]

Re: Evinrude 200/ 19 ft glasply-WOT=64-6500

I have a 19 ft glas-ply, 200 hp evinrude 2 stroke, on a bracket. the prop on there is a 15x17 alum. Running wide open the RPMs are in the 6450 range. I think thats too high, but I dont know for sure. the boat performs great, jumps right up, does aallllmost 50 mph. I want to upgrade to a stainless prop, but because of where i live, going to a shop, borrowing props, etc, is not feasable. im on a remote island in alaska, so its pretty much, do my homework, buy a prop, and live with it.
i want to A, get any fuel economy i can get, B, going faster is always positive, and C, lower my rpms down to...? i dont know.

so a couple questions. do i have to stay at the same diameter? would i notice a difference in fuel consumption by dropping to a 14.5 or 14.75?

assuming i got a 14.75x19 in stainless, what would be different between a 3 or a 4 blade?

finally, WHAT AM I NOT AWARE OF? Its easy to ask questions, but i know theres things i dont know about, and i welcome any and all advice. thanks for any help.

Not an expert but::
Not knowing the year of your motor it is difficult to know its rpm range.
After 84 200s were rated at 5,500.Most run 300 or so above hp rpm range with a light load so it is at its max with a load.It's pretty obvious your pretty high. Going stainless will drop you about 200,a 19 about 300 to 400.These figures aren't carved in stone.
So you could be at 5,900 still a little high but it should preserve your hole shot though it will be somewhat less, top end may improve.
Generally a 4 blade is to improve low end performance but usually with the sacrifice of top end.No doubt someone will be along with more specific info.

 

[benpsg]

Re: Evinrude 200/ 19 ft glasply-WOT=64-6500

dang, thought i had given all relevant info. my bad. motor is a 93. how exactly do i tell if i have a cupped prop? is cupped DISTINCT or not? also, im usually running light load. just me in the boat, fuel, and not much else. general use, run out to fish, idle or anchor, pull some pots or longline gear, go home. nothing crazy. and i definitely like the top end as "top" as possible.

thanks for the help, and please elaborate more if you have any more info. thanks again.

 

[steelespike]

Re: Evinrude 200/ 19 ft glasply-WOT=64-6500

I don't have the rpm specs for 93 but most likely in that 5,500 range I mentioned.
Keeping in mind I'm not an expert I do believe you can see the cupping along the edge of the blades.Without cup the blades appear smooth to the edge.I think I would stick with the 19" pitch stainless.If the rpm is too high just throttle back a little.Speed will probably still be better than the 17".

 

[benpsg]

Re: Evinrude 200/ 19 ft glasply-WOT=64-6500

thanks for all the help. one last thing, no one seemed to comment on it....should i stay with the same 15'' diameter? im looking at props online, and there are ones bigger (like 15 3/4'') and smaller. what are your thoughts on that? thanks again

 

[steelespike]

Re: Evinrude 200/ 19 ft glasply-WOT=64-6500

thanks for all the help. one last thing, no one seemed to comment on it....should i stay with the same 15'' diameter? im looking at props online, and there are ones bigger (like 15 3/4'') and smaller. what are your thoughts on that? thanks again

I would stay with the smaller prop no bigger than 15".Generally larger props are for heavier loads, heavier boats.

 

[Dhadley]

Re: Evinrude 200/ 19 ft glasply-WOT=64-6500

On a 93 the rev limiter is at either 6200 or 6700 depending on which pack you have. Since you're at 6400 now we'll assume your pack has the 6700 limiter.

However, I would check the setting on the tach. Make sure it's on position 6. It might be correct and the aluminum prop simply does have over 20% slip but it'd be worth a look.

The other thing is to look at the power pack. Somewhere it will say 62L or 67L or something similar. If it says 62L then we know the tach is off.

 

[ezeke]

Re: Evinrude 200/ 19 ft glasply-WOT=64-6500

You will normally get somewhat higher RPM with a SS prop that is otherwise the same type and size as your aluminum.

[Edit] Based on everything else that I read here, you would probably be well off with a 15 X 15 Stainless. As Dhadley said the rev limiter on the power pack will cap the RPM, most likely at 6700.

BTW, iboats has a listing today for a 15 X 15 Michigan SS prop that is an excellent deal. It is the same propeller that I have on my motor:

http://www.iboats.com/mall/propfind...id=125&**********=050788780&*******=527059693

 

[rndn]

Re: Evinrude 200/ 19 ft glasply-WOT=64-6500

You will normally get somewhat higher RPM with a SS prop that is otherwise the same type and size as your aluminum.

[Edit] Based on everything else that I read here, you would probably be well off with a 15 X 15 Stainless. As Dhadley said the rev limiter on the power pack will cap the RPM, most likely at 6700.

BTW, iboats has a listing today for a 15 X 15 Michigan SS prop that is an excellent deal. It is the same propeller that I have on my motor:

http://www.iboats.com/mall/propfind...id=125&**********=050788780&*******=527059693

Why would he want to go to a 15" prop?? He wants to lower his RPM's. Are you just suggesting this because you have the 15" for sale?

 

[ezeke]

Re: Evinrude 200/ 19 ft glasply-WOT=64-6500

Response to RNDN

I don't have anything for sale.

If there is too much slip, lowering pitch will reduce slip & RPM, all other things being equal.

The iboats prop price is 66% off, that is the only reason that I mentioned it.

 

[rndn]

Re: Evinrude 200/ 19 ft glasply-WOT=64-6500

I was joking about having a prop for sale. I have never heard of anyone trying to lower their RPM's by de-propping. It's a sure fire way to over revving your engine.
The propper way to lower the RPM's is by adding pitch not removing it.

 

[steelespike]

Re: Evinrude 200/ 19 ft glasply-WOT=64-6500

I was joking about having a prop for sale. I have never heard of anyone trying to lower their RPM's by de-propping. It's a sure fire way to over revving your engine.
The propper way to lower the RPM's is by adding pitch not removing it.

What he said.Increasing pitch and/or diameter lowers rpm.

 

[benpsg]

Re: Evinrude 200/ 19 ft glasply-WOT=64-6500

What exactly is the powerpack? Dumb question, cause i have a manual and could look it up online. I should be able to put it in the water this weekend, and get a final for sure exact rpm readout.

since a higher pitch decreses your holeshot, but goes faster top end, and a 4 blade increases your holeshot, but loses top end, what about going with a 21 pitch 4 blade? more holeshot, more top end? what do you think?

thanks

 

[Dhadley]

Re: Evinrude 200/ 19 ft glasply-WOT=64-6500

On a 93 200 OMC the pack is located right behind the flywheel and on top of the block. There are 2 screws and 2 nuts holding it. The numbers should be on the side.

A higher pitch doesn't necessarily mean a worse holeshot, just like a 4 blade doen't always mean less top speed. A 4 blade generally, again - not always, will carry a load better and tends to have more tail lift than bow lift.

You need to determine what your particular rig, with your normal load and normal operating situation, needs. Again we'll talk generalities - boats with motors on brackets tend to not need bow lift because of the motor offset. Some still do.

If you need bow lift then you'll go with something like a Raker (old style) or better yet a Turbo Lightning. Or even the old Turbo II if you could locate one.

 

[Texasmark]

Re: Evinrude 200/ 19 ft glasply-WOT=64-6500

Not necessarily so, on depropping and increasing rpm's. I went from a 24P HP SS to a Hustler 23P HP alum, and lost 600 rpm's and 3 mph. The converse is true also for if he decides to go with the 15 x 15. Both were high rake and cupped, but the diff is probably in the blade thickness and resultant drag. SS is just more efficient.

Mark