need more power from MCX 350
 

To those of you who are mechanically inclined please help. I have an 08 x-star with the MCX 350 engine. When running the flyhigh x-star bags my boat takes a long time to get up to speed. I have already changed the propeller. Is there anything I can do to boost my power?

What is happening...slow to plane? what are the rpm's when when you hit the throttle on a start? How much weight in boat with ballast? Which prop are you running now?

Are the ballast fat sacks all in the back or do you have weight up front as well?


Adding HP to your mcx will be hard. Only due to the fact that the computer (ECM) will be programed for the factory mcx setup. I know that it is possible to reflash a automobile ECM but in the marine world it is hard. If you find someone able to do it, then it will be expensive.


Engine parts are the cheap side the fine tuning of the computer could cost a fortune.


What prop like mentioned above?

Does the boat run like it is designed to do without weight and only you driving?

What prop, more importantly, who recommended the prop?

It is a shallower prop. My boat is in storage right now so i will have to take a shor trip to get you actual information on it. I purchased the boat used and the guy I got it from said he put that prop on to help with getting out of the hole faster when running ballast. I would imagine the origional prop would make it worse but i have not tried it. For ballast I fill the hard tanks plus the 2 rear and 2 front flyhigh sacs made for the x star.

don't take offense to this...

you absolutely sure you need a wake that big?
if you think you do...
try dumping the rear hardtanks... if you have people on board they do absolutely nothing to help the wake. add a 350# walkway sac to the bow and drive very, very carefully.

While the MCX is no super-powerful engine it should get the job done for you with the correct prop. We need to know what props you have tried.

WillyT is right, not many riders would need that much weight.
My setup now is (2) 400# sacs in rear lockers (soon to be 720's), full KGB and 750# sac in front walkway.
I don't use the rear hard tanks at all.

Jeff Barton, Keith Lyman and Josh Palma seem to like it fine. :D

If you want noticeable power, you will have to add serious hardware (like a supercharger) to your engine. An ECM reflash or other small bits won't give you the kind of power increase you are talking about. Do what you can with the prop and then you might have to go big money if that won't help enough.

Unscrew throttle knob, sell boat, replace with boat with larger engine. Sorry. But modding the MCX for more power is going to be crazy expensive and probably impossible due to software restrictions. The advertised hp is supposedly a little on the high side. And by "a little," I mean a lot.

But as mentioned above, repropping is probably your best bet in your current setup.

Good luck.

The most aggressive props out there are the OJ 14.75x13 and the acme 15x12