I have a 1990 Suzuki 85 hp 2 stroke.  It has 3 carburators stacked one on top of the other and they are at the part of the motor closest to the stern and the openings face the stern.  There is a black plastic cover that covers all of the carburator openings, I guess to protect them.  I have a couple of questions about this.

1.  With the motor cover on and that plastic covering over the carburators, how are they able to suck in enough air?

2.  What would happen if I drilled a 3-inch diameter hole in the motor cover in front of each carburator and also in the plastic covering and then put  air filters over the holes so no debris could get into the carbs?  This would allow more air to be sucked into the carburators right?  Maybe it's a dumb idea, but if the carbs were able to get more air, shouldn't that increase my horsepower.  Just a wild theory, but I wanted to know what you guys thought about that.

Hi I would not do anything like what you are suggesting. first of there is enough air getting to the carbs. the air comes from behind the carbs. that plastic helps direct the air. that plastic is not only keeping debris out, but it is also keeping water out and it stops flames when you have a back fire.  You put holes like you said an air cleaniers. and run in rain or catch some spray form a wave your motor will get washed out and be toast. If you want to try running it with out the plastic cove just take it off its only like 10 screws or so, but you will see no improvement is power or speed, only noise.

I agree with HPBB, Suzuki designed it that way for a reason. If it were hindering performance they would have redesigned it.

And if it were hindering performance(which I'm sure it isn't), you would have to alter the jetting once any changes were made to realize a performance gain.

#1 problem with your plan, two strokes motors do not like going directly into the carbs are you are suggesting.  I disrupts the air flow throught the reed cages and will acutally hurt your peformance.

The outer shell mormally have the built in capability to pass more than enough air to supply the motor.

That inner plastic cover is the air silencer.  It's to keep down the noise the carbs make when motor is running.

With some motors, (can't say about yours since I've never messed with one) the air silencer is restrictive and designed that way.  If you remove it or reduce the restriction you may have go up several jet sizes in the carbs or it will lean the motor out and melt a piston or two.  It would also be debateable if you would see any performance gain by removing it and going up in jet size if required.  It would make a lot more noise inside the boat at WOT.

Thanks for the replies.  I figured that Suzuki would have designed it the way it is for a good reason.  I just was wondering about that, but you guys are wise enough to not let me destroy my motor, which runs great as it is.  Point taken.  Note to self....If I want more horsepower, get a bigger motor!