200hp merc.. is it a safe WOT? & fuel efficiency?

[200mark]

My '85 200hp merc is revving high due to using a small prop. How high should I rev this before giving up on finding WOT? Already gone to about 6200rpm & still some throttle left & motor is climbing. Also, I was wondering what is a good rpm for fuel efficiency when cruising, & best rpm's for fuel efficient skiing?

Being an older motor, I didn't want to rev it too high & have it fall apart or something. Can I get a bitta guidance on this? thanks :%

 

[200mark]

Re: 200hp merc.. is it a safe WOT? & fuel efficiency?

Sorry, just for more of an idea, it's on a 16'6" runabout. Fairly light 'Pride Panther' & an 18P 4 blade prop. So itz going quick & I will look at a 21P for faster skiing & cruising, but just interested in the max revs I should push it to. thanks

 

[LubeDude]

Re: 200hp merc.. is it a safe WOT? & fuel efficiency?

Hi 200Mark, you can spin that 200 6,000 all day if it has been taken care of. You should shoot for a WOT RPM of around 5,500-5,800 though.

Also, it is very obvious that you are a "VERY" over powered. Please be carefull.

 

[deejaycee_2000]

Re: 200hp merc.. is it a safe WOT? & fuel efficiency?

nice setup, my kinda boat ...... what speeds do you get out of it? ...... like Lube Dude sais keep it between 5500 - 5800 max ..... I would fit a nice 21p stainless 3 blade prop ..... enjoy

 

[200mark]

Re: 200hp merc.. is it a safe WOT? & fuel efficiency?

Thanks for the reply. yeah it is well powered for the hull, which is great for skiing. nothing worse than having to hang on while the boat pulls you out (specially at my age, haha). with the 18P @ 6000rpm, its hitting 50mph (speedo). The 18 is great for wakeboarding, tubing and learner skiiers etc. But yeah, maybe the 21P will give me more speed. I'd like to be hitting at least 65mph, for a bitta fast boating and skiing (love speed). would even like to get 70mph out of it down the track, would like to do a little social ski racing (70 would be enough for me). Do you think a 21P would do it, or should I even check a 23P? Also, when cruising, whats a good rpm for fuel efficiency etc.?
Thanks again.

 

[JasonJ]

Re: 200hp merc.. is it a safe WOT? & fuel efficiency?

I would see if you can test drive a 21 and a 23. Just don't damage the props or you'll have to buy them. Definately stainless, maybe a four blade, since you clearly have power to spare. You would get maximum speed from a three blade, but since you also ski, the four blade would better help keep that power under check. I am guessing based on what you are saying that a 23 pitch is probably going to be your speed prop, and it may work for skiing as well, since you have that nuclear reactor hangin' off the back of that boat...

 

[deejaycee_2000]

Re: 200hp merc.. is it a safe WOT? & fuel efficiency?

I agree, experiment with the 21 pitch and 23 pitch but stick with 3-blade and stainless ..... when cruising best rpm for fuel would be about between 3000 - 3500 rpm with the motor tilted up slightly ......