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  Max outboard rpm?

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Author Topic:   Max outboard rpm?
mustang7nh posted 03-19-2003 12:28 PM ET (US)   Profile for mustang7nh   Send Email to mustang7nh  
Does anyone know the max factory suggested
WOT rpm on a 1988 200 Johnson? I get 5400 but want to know if I can twist
her higher with less pitch without self destructing.
Bigshot posted 03-19-2003 01:20 PM ET (US)     Profile for Bigshot  Send Email to Bigshot     
Does the block say V6 on the back hump between the cylinder heads? If so she redlines at 6k.
Sal DiMercurio posted 03-19-2003 07:00 PM ET (US)     Profile for Sal DiMercurio  Send Email to Sal DiMercurio     
You want to get as close to 6,000 rpms as you can with that engine, at wot, trimmed out, & normal load.
If you drop 2 inchs of pitch, it will get you 5,800
My thoughts are, your twisting a 14.5 x 19 or 15 x 19 & you need to drop to a 15 x 16 s/s [ yes, omc makes a 15 x 16 s/s ] should put you right at 6,000 rpms.
You would probably be better off with a 14.25 x 17 Stiletto [ $249.00 at aftermarket ]& raise your engine up a hole or 2.
See BS, I don't always disagree with you.
Sal
Buckda posted 03-19-2003 07:51 PM ET (US)     Profile for Buckda  Send Email to Buckda     
Mustang7nh -

You may wish to purchase a Clymers or similar manual for your engine. I just received one in the mail (best 32 bucks I've spent this month) and it has all the information you will ever need in it..and best thing is, it is focused on your engine. Not knocking BigShot or Sal - contrary - reading their posts over the last year has convinced me that if I get a chance to meet them and chew the fat about boats, it will be a chance I wont want to miss - but the manual will give you exact information.

Dave

Sal DiMercurio posted 03-19-2003 11:55 PM ET (US)     Profile for Sal DiMercurio  Send Email to Sal DiMercurio     
I agree with Dave 100%.
Sal
mustang7nh posted 03-21-2003 01:00 PM ET (US)     Profile for mustang7nh  Send Email to mustang7nh     
I currently have a 14.5 X 19 stock original 1988 OMC ss prop. Pretty good shape. If I drop to the Stilletto 17 and raise it up an inch will 6000rpm send this thing to an early grave on her 15th season? While I don't plan on running for extended periods of time at WOT it is sometimes nice to do a 1-2 minute burst. Thanks for the advice.
Bigshot posted 03-21-2003 02:02 PM ET (US)     Profile for Bigshot  Send Email to Bigshot     
You will not get 6k with a 17" you may get 5800. Running it with the 19 is fine if that is where your load is. If when you put 4 people and a full tank of fuel and she runs at 49-5000 is where you will harm the engine. This is not a car where you think high rpms mean less durability. Consider this like a 5sp where lugging it will ruin an engine faster than running it up to redline. Engines don't knock when running higher like they do lugging right?
Bigshot posted 03-21-2003 02:03 PM ET (US)     Profile for Bigshot  Send Email to Bigshot     
that is supposed to be a "5spd car".
Sal DiMercurio posted 03-21-2003 04:32 PM ET (US)     Profile for Sal DiMercurio  Send Email to Sal DiMercurio     
Bigshot is right, you will only get 5,800 by going to a 17p, but if you can raise your engine, you should gain 100 rpms per hole raised.
I don't recommend running that 15 year old engine for long periods of time at 6,000 rpms, but being able to get there, allows your engine to run easier throughout your whole rpm range, like down shifting in a stick shift, allows the engine to breath far easier.
You could also loose rpms by going to a 17p stiletto, as it could run more efficient & drop your rpms.
You have to try it before you buy it.
Another senario is, try a Michigan Raptor 14.25x17 & see what it does, because the stiletto & Raptor are very much alike.
The Raptor is more expensive, but results are very close to the same.
Sal
mustang7nh posted 03-22-2003 08:47 PM ET (US)     Profile for mustang7nh  Send Email to mustang7nh     
My tach died before I did my speed to rpm calculations. But before it died I knew I got 5400 WOT and 44mph (1 person 1/8 fuel light chop). With 3 adults and 50 gal fuel and chop, I only droped 2-3 mph in top end. My cavatation plate seems even with the keel, can I still go up a hole or two if I go with a stilletto to grab the water more or will the position be too high (20 Outrage 1988). Thanks
Sal DiMercurio posted 03-22-2003 09:48 PM ET (US)     Profile for Sal DiMercurio  Send Email to Sal DiMercurio     
Sure you can, i'm running up on the 3rd set of holes & could possibly go up to the 4th.
Before you go out & buy a new Stiletto, try raising your engine a couple holes, [ 3rd set ] with the prop you have now, i'm sure you will gain a couple hundred rpms.
If she blows ouit, bring her back down 1 hole.
I have a feeling if you go to a Stiletto, you will have to drop your pitch to a 17, because it "should" bite better [ less slip ]then the stock omc .
Sal
Sal DiMercurio posted 03-23-2003 08:56 PM ET (US)     Profile for Sal DiMercurio  Send Email to Sal DiMercurio     
I made a typo a couple posts up, I said it's possibly for you to loose rpms by going to a Stiletto 17p because it could be more efficient, I meant a 19p.
You may only gain 300 rpms by going to a 17p Stiletto for the reason above.
Sal
mustang7nh posted 04-11-2003 07:52 PM ET (US)     Profile for mustang7nh  Send Email to mustang7nh     
Bigshot,

How sure are you on the 6000 redline? Yes, it says V6 on the rear of the block between the heads. 1988 200 Johnson. If I reprop and push 6g's I don't to be rowing home :)

I might be calling Bablyon for a tow :)

Thanks

Sal DiMercurio posted 04-11-2003 10:26 PM ET (US)     Profile for Sal DiMercurio  Send Email to Sal DiMercurio     
6,000 rpms is the recommended rpm for that engine.
Sal
mustang7nh posted 04-12-2003 07:24 AM ET (US)     Profile for mustang7nh  Send Email to mustang7nh     
Thanks Sal,

I've got a 14.5x19 SS OMC prop. Its 14 years old, been reconned three times and is ready for another (if I were to keep it)recon. Diameter has shrunk to a tad over 14" due to all the recon. WOT last year was 5400 with three adults, 20 gallons of fuel.

I'm going up two holes and will like to get a Stilletto. Does a 17 sound like it put me closer to 6 without going over? You mentioned that the Stilletto is alot of bang for the buck, but are the Raptor better? Thtanks

Sal DiMercurio posted 04-12-2003 11:49 AM ET (US)     Profile for Sal DiMercurio  Send Email to Sal DiMercurio     
The Raptor & Stiletto are so close that theres very little difference, no advantage to either one being better then the other.
I would certainly go with the Stiletto 14.25 x 17 & up 2 holes & see how she hangs on.
If she breaks loose, bring her back down a hole.
You should get very close to 5,900 - 6,000 if your engine is running right.
The 17 Stiletto might not allow you to get to 6,000 as it might be more efficient & bite better, but you will notice a big difference in the way the boat rides & handles.
The reason I say go with the Stiletto is, they are the best bang for the buck for the everyday guy.
You could also go with a Mazco prop for $1,200 & probably gain 3 mph at top end.
Sal
mustang7nh posted 04-12-2003 09:39 PM ET (US)     Profile for mustang7nh  Send Email to mustang7nh     
Thanks
jimh posted 04-13-2003 11:20 PM ET (US)     Profile for jimh  Send Email to jimh     
I think the most definitive source of information about the maxium rated crankcase speed of an outboard engine would be the owner's manual that came with the engine. It usually lists specifications like that.
Sal DiMercurio posted 04-14-2003 12:45 AM ET (US)     Profile for Sal DiMercurio  Send Email to Sal DiMercurio     
Jim, your absolutely right, but in this case, i'm 99-9/10 positive those older 200s really need to see 6,000 rpms
I'v worked on many of them & they [ manufacturer ] stress getting 6,000.
Sal

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