1998 Johnson 225?

You talking at cruise or WOT? I always thought the rule of thumb was every 10 HP was 1 GPH at WOT, so 22gph.

-Svence
 
Expect fuel burn numbers of 15-18 GPH at a 4000 RPM cruise from that engine, and right around 25-27 at 5800. The older 88-92 engines are MUCH better on fuel, but the later 93+ have pretty pretty trouble free and reliable with the exception of block rot if they aren't flushed out good.
 
Wow...lotta fuel flowin there. Probably a deal breaker for me. Just can't stand the thought of 15 gph cruise to go tbuing with the kids. Funny...wouldn't be such a big deal on feeshin trips
 
It's actually not horrible fuel burn for an engine that size. A 150 EVINRUDE of the same era cruising at 4200 can burn right at 13-14 GPH. My cross breed 225 burns 11 GPH at 3800 according to my fuel flow meter, but it always says I've used more fuel than I actaully have. Around 4000 I'm pretty sure I'm burning about 12.5 GPH though with it. The 93+ engines have finger ports in them which boosts the power output, so OMC made the exhaust smaller in them to help clean-up the emissions. The smaller exhaust makes it work harder at cruise, but the finger ports allows them to make the HP that the older engines made. Gotta love the EPA don't ya.
 
I have a 1996 225 loop with a 21pitch prop on my v-20 and I average 2 miles per gallon. I typically cruise between 3000-3500 and rarely run wot since this the 225 is more power than the boat needs or was designed for. I will say that it is a dependable good running engine.
 
Jetty Rocker said:
I have a 1996 225 loop with a 21pitch prop on my v-20 and I average 2 miles per gallon. I typically cruise between 3000-3500 and rarely run wot since this the 225 is more power than the boat needs or was designed for. I will say that it is a dependable good running engine.
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A 21 pitch is overkill for a V-20 with a 225, try a 17 large diameter or 19 small diamter and your economy will go up some. I run a 225+(slightly modded) on my 20 HYDRA-SPORTS and just tonight had it running 49MPH turning 5800 with a 17 large diameter. My hull is a bit heavier than a V-20 and I'm averaging around 2.1-2.2 NMPG(roughly 2.4-2.5 MPG in statute miles).
 
Thanks for the info Ferm. I'm not sure if I have been using nautical miles or statute, that was a good point. I had been running a worn out 19p and my cruising rpms were 3500-4000. The reason that I went to the 21p was to lower my cruising rpms thinking that would increse my mpg's. I will start checking my mileage again and compare.
 
Jetty Rocker said:
Thanks for the info Ferm. I'm not sure if I have been using nautical miles or statute, that was a good point. I had been running a worn out 19p and my cruising rpms were 3500-4000. The reason that I went to the 21p was to lower my cruising rpms thinking that would increse my mpg's. I will start checking my mileage again and compare.
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You need to make certain you can hit at least 5600 with a good load in the boat, any less and your lugging it and milage will suffer. With a light load I can hit 51 MPH turning 5900 with mine, and that's with an APOLLO large diamter 17 pitch. I could step down to a 4 blade small diameter and probably hit 53, but my cruise would suffer. My first prop was a 15 pitch STILLETTO and when I ran it I had 200 carbs on it and turned about 6100 max running 48MPH, but my milage was only 1.5-1.6 NMPG. The large diamter got me ALOT more cruising speed and economy, and the bigger carbs got me my top end charge.
 
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