mercury 650 x

[excalibur]

hellon every body
i'm new on this forum, i'm french so sorry for my bad english.

Can you give me some infomation about the "650X" mercury racing outboard:
Horsepower
Rpm max
Type of boat
Race years
Propellers

If you have photo, parts or other i'm very interested.

Thank's by advance

Pierre-paul

[sam]

I believe the 650X was only produced in 1974 and soon replaced by the 700X which was produced thru 1977. In the US it was raced in the Mod50 class, generally in Europe it was raced in class OE on tunnel hull boats (like F3).

There was never any information released on horsepower. Max RPM range in the early 1974 catalog says 7,000 to 7,200 rpm. Based on similar OMC race motors and the slightly less powerful Mercury 650XS rated at 90 hp it would be reasonable to estimate the 650X was approximately 105 hp.

The 650X uses the Mercury Super Speedmaster lower unit and takes special 12 splined propellers. Props for the 650X are very hard to find unless the motor has the 13:16 gear ratio.

http://i256.photobucket.com/albums/h...ff/74-2-2r.jpg

IMG code for this forum is apparently turned off

[pat]

Good review of the 650 XS. I raced against plenty of them in EP (Canada) with a OMC 75 HP Hustler and for the most part it was an even match. I don't think that any I saw were in the 105 HP range but closer to the 90 HP range. A good dyno-broke OMC SST-60 could grab 100-105 HP with the right crank and block.

I also saw alot of Mod 50 races with both OMC F3 and Merc 700X engines. Pretty well a toss-up.

[RTM]

Sam, got any idea on what the weight is for the Merc 650X? Number of cylinders?
Rich

[sam]

All three of these motors share the same basic 3 cylinder 49 cubic inch configuration of the Merc 650 pleasure motor but have 3 carbs instead of 2. I'll have to look up the weight when I am back home.