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Author Topic:   rpm range on Yam225 OX66 EFI?
mustang7nh posted 09-08-2003 10:29 AM ET (US)   Profile for mustang7nh   Send Email to mustang7nh  
I just bought the boat and the seller says its a 96 engine, although a mechanic says Yam didn't go to EFI until 97. It definitely is a OX66 EFI. Does anyone know the WOT range for this application? I'm mounted up pretty high and with alot of trim I max at 5200. Thanks
Peter posted 09-08-2003 11:36 AM ET (US)     Profile for Peter  Send Email to Peter     
What is the boat configuration again? What brand and diameter of propeller are your running? The bracket on the motor has a "born on" date. If it is late 1996 then it is a 1997 model.

My recollection is a 22 Cuddy standard transom. If you are running a 15.25 x 17" Saltwater Series propeller, the best you will see is about 5300 rpm when the O2 sensor is clean. Based on my assumptions of your rig, 5200 sounds about right.

kingfish posted 09-08-2003 11:47 AM ET (US)     Profile for kingfish  Send Email to kingfish     
WOT range, according to Yamaha, is 4500 to 5500 RPM for a 225 OX66.
mustang7nh posted 09-08-2003 01:19 PM ET (US)     Profile for mustang7nh  Send Email to mustang7nh     
I'll check the born on date and prop. Its a standard notched transom non-cuddy Outrage 22. No bottom paint, mounted up pretty high, 48mph at 5200. Prop is like new but is likely your standard saltwater series OEM.
mustang7nh posted 09-08-2003 01:25 PM ET (US)     Profile for mustang7nh  Send Email to mustang7nh     
Is there any downside to proping the engine so it goes from 5200 to the max recommended rpm of 5500? Does it impact longevity much? I know you don't want an engine over propped but I don't think mine is by a long shot, but does it make sense to try to squeeze another 300rpm out of her? Will it hurt mid range performance?
Peter posted 09-08-2003 01:28 PM ET (US)     Profile for Peter  Send Email to Peter     
Your numbers suggest you are running a 19 inch pitch and if that is so, your engine is running fine and I'd leave everything well alone. A 17 inch pitch version of the same propeller would be too small as it would put WOT up to 5600.
mustang7nh posted 09-08-2003 02:30 PM ET (US)     Profile for mustang7nh  Send Email to mustang7nh     
Thanks Peter,

I agree, if its not broken don't fix it. But its ever so temping when you hear someone's got the same boat that is faster than yours :)

Would a 19" with some more rake or cup or something bring up the rpm without going over? Thanks again.

Peter posted 09-08-2003 07:38 PM ET (US)     Profile for Peter  Send Email to Peter     
More cup should reduce rpm, not increase it. I'm not sure how rake will effect rpm. I think that 48 mph in a 22 Outrage is going to be about as good as it gets with a 225 Yamaha.

There is no downside to propping the engine so it achieves 5500 but you should select a prop based on your normally loaded conditions. I submit here that your prop is the probably selected as the right one for all around use.

reelescape1 posted 09-11-2003 11:18 AM ET (US)     Profile for reelescape1  Send Email to reelescape1     
I have a 90 22 OR and repowered last spring with a Yam 225 EFI OX66...running a 19 yam ss prop, engine mounted 1 hole down, 5000-5100 rpm. I tried the 17 prop and hit 5700-5800...too much for my liking! The book says 4500-5500 operating range.
Peter posted 09-11-2003 04:18 PM ET (US)     Profile for Peter  Send Email to Peter     

Going up 600-700 rpm from a 19 to 1 17 doesn't make sense to me unless they were different brands.

mustang7nh posted 09-12-2003 07:37 AM ET (US)     Profile for mustang7nh  Send Email to mustang7nh     
Reel- sounds like I'm about right then. I get 5100 and I'm mounted such that I can only go "up" one more hole. My prop appears to be the same Yam 22 19".


jimh posted 09-12-2003 10:47 AM ET (US)     Profile for jimh  Send Email to jimh     
The best reference source for determining the recommend maximum operating range of an engine is the Owner's Manual that was originally delivered with the engine. In addition to this information, the manual will be loaded with other important specifications, advice, and procedures. I cannot image not having one.

I recommend you contact your Yamaha dealer and order a replacement manual. It will answer many of your questions with authority.

Peter posted 09-12-2003 11:05 AM ET (US)     Profile for Peter  Send Email to Peter     
Yamaha has provided operator's manuals on-line for free at .
mustang7nh posted 09-12-2003 03:08 PM ET (US)     Profile for mustang7nh  Send Email to mustang7nh     
Is the 96/97 Yam OX66 the 3.1 block? The manual online only goes back to 98. Thanks
Peter posted 09-12-2003 03:11 PM ET (US)     Profile for Peter  Send Email to Peter     
Yes. Yamaha never made a small block (2.6L) 225 EFI. Largest hp for the EFI 2.6L block is 200. WOT operating range for the 3.1L 225 is 4500 to 5500 rpm.
jimh posted 09-14-2003 02:12 PM ET (US)     Profile for jimh  Send Email to jimh     
Pointing to as a source of the on-line manuals leaves you about ten clicks short of a manual.


From there choose your path to the outboard manual you seek.

You can only look at the manuals; you cannot print them.

Peter posted 09-14-2003 08:53 PM ET (US)     Profile for Peter  Send Email to Peter     
So sorry. My appologies. How unthoughtful of me.

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