Re: 85 Force Power Reeds
Some guys swear by Boyeson reeds. Personally, I have never tried them and think they look cheap. I just don't want to spend that kind of money for a possible marginal increase in power. The only positive I see to them is if you do break a reed petal, it will pass through the engine without doing harm.
You can try them and see if you get more power but in reality, if you do, it will still only add up to 1 or 2 MPH more.
There is no carb change that will yeild more power so forget that, and it is almost impossible to "pack" the crankcase.
If you are not worried about disassembling the engine, porting will yeild useable power increases. I have tried streamlining the reed vee blocks with zero increase in power over simply porting the engine.
HOWEVER: Remember that you are dealing with 50 year old design technology. Short con rods, standard crossflow design, crankcase big enough for a cat to wag its tail, small bearings, and so forth. The engine was designed to be a good, reliable, entry level, general purpose engine. There is no esoteric design that can be "squeeked."
Best way to get more power is to trade it for a 120 or 125. 120 would be my choice--stronger than the 125. Since the 85 is a small bore engine (3.3125), even the stock big bore 90 (3.375) will beat it hollow. However, don't think that overboring the engine will increase power Even at a maximum of .030 over, there is just not enough cubic inches gained to make a noticeable difference.
However, if you insist, port the engine and experiment with transom height and props. If it is earlier than 1994, and if it has a 1.72 to 1 lower unit, install a 2 to 1 ratio lower and increase prop pitch 2 inches. That alone will yeild a couple of MPH more. Porting, if done correctly, can yeild 5-10 horsepower more per cylinder.
The reeds didnt make much diff at top speed but helped out of the whole and raised rpms by 200, dont regret doing would recommend,and yes they do look pretty cheap but they did help a little.