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View Full Version : Difference between 175 and 200 merc......



Arizona Hotboater
05-19-2001, 12:55 PM
OK, if one has a 175 2.4 block, can a 200 be built from it or is the porting different? I have heard the port timing may be different but then heard only the tuner and carbs are different. A friend is putting together a motor and has everything he needs but has a block choice between an 81 225 and a vertical reed 175. He has a 14 petal and a 10 petal front half with intakes to use either way he goes on the block. Whats the deal?
Thanks,
AZH

[Edited by Arizona Hotboater on 05-19-2001 at 12:58 PM]

stan merck
05-19-2001, 02:26 PM
A 175 2.4 HAS VERTICAL REEDS. THE PORTING IS THE SAME AS A 1983 AND UP 200. IT HAS FINGER PORTS. THE 225 DOESNT HAVE FINGER PORTS. I WOULD RUN THE 175 BLOCK WITH EITHER A 5 PETAL OR 7 PETAL HOR FRONT HALF.THE 7 PETAL MAKES MORE POWER BUT HAS LESS LOW END THAN THE 5 PETAL HOR SETUP. I DONT THINK ITS THAT MUCH LOWEND LOSS THOUGH.I HAVE RAN 225 BEFORE AND THEY ARE PRETTY STRONG ON LOW END.HE WOULD BASICALLY JUST HAVE A FINGER PORTED 225. MAKE SURE YOU RUN A 200 DIVIDER PLATE AND A 200 TUNER A #41941. THE 175 MAY HAVE THE SAME DIVIDER PLATE AS A 200 ALREADY I AM NOT SURE. THE 175 CARBS AND 200 ARE THE SAME SIZE. THE 225 HAD THE BIGGER CARBS RUN THESE FOR MORE TOP END. ALSO WHEN MERCURY PROPRATED IN 1982 THE 225 WAS CALLED A 2OO THAT YEAR THEN IN 1983 THE LATER FINGERPORTED 200 BLOCKS CAME OUT. HOPE THIS HELPS SOME.

Greg Moss
05-20-2001, 07:31 AM
The difference in the blocks was the head bolts you must look at the bolt pattern. the 2.4 til 1984 had the head bolts next to the cylinder liner.1985 and after they where in the water jackets. Make sure you check this out also. all2.4 before 85 did not have finger ports. Either intake will work but if you are going to use the 14 pedal you will need to use the WH-20 carbs. The 225 should of come with them. The low end does not suffer that bad with the big reeds, You will hear different oppinions on this but that is all I run> I have run them both ways and there is not that much difference on the hole shot to notice, the big difference is on the big end you should see more RPM with the 14 pedal. hope you have good luck at the lake today. Greg

hawktuner
01-14-2005, 10:27 PM
Just a thanks to all of you guys for this extremely detailed information!!
I've got an 89 Merc 2.0liter on my 18ft Sea Ray, but I'm trying to get an older 2.4 to rebuild and get more power.

It's just a family ski boat, but I dig playing with ANY type of motor, and now that I've had this thing for a year, I'm itching to get into it.

I'm just starting out and I've read so many posts and I'm learning everything
I need to know. You guys have done it all before!


The funny thing is that the posts I'm learning so much from are from 2001.

Thanks a bunch for sharing the tech info!

QUICKSILVER
01-17-2005, 04:38 PM
stan merck had the facts correct, he just didn't mention the head bolt change. That was also in 1983.