Mercury 150 Preformance issue

[Bassguy64]

Hello guys & gals I just became a member today and I'm in need of some help. I have a 1985 Mercury 150 hp V-6 (carb motor) on a 17' champion bass boat. It runs great and very fast. The previous owner had some Mercury preformance work done, installed carbs off of a 175 hp and the lower exhaust cavity leading to the prop exhaust has been drilled with two 3/4" holes on each side of the lower unit. These upgrades seem to work well as the boat tickles 70 mph with the high-5 prop, my problem is it is CRAZY LOUD. I was wondering if I could tap these holes and install plugs to return the exhaust to more of a stock db. without messing up the air / fuel mixture and thus causing damage to the motor ? As I am more of a fishing freak than a speed freak i am more than willing to give up mph for a little peace and quiet. Thanks for your concideration to my problem Regards Butch

 

[Phunahm]

Re: Mercury 150 Preformance issue

WoW You have almost the same stuff I do except the Hipo work I have a 1986,17' Glastream With a 150 XR2 it does 70mph with a four blade I don't have an answer for you on plugging the holes dunno why you couldn't however I really never heard of drilling out the exhaust...Can you take some pics of it?....

 

[Faztbullet]

Re: Mercury 150 Preformance issue

Plug em and go.. will not effect fuel/air settings and should actually improve holeshot!!

 

[Bassguy64]

Re: Mercury 150 Preformance issue

It sounds like our rides would be a heads up drag race, sorry I cant take pics now as the boats floating up at the cabin. Im only planning to take it out to plug the exhaust holes or this fall after the seasons over. So far my only concrete solution to the problem is to go slow to the fishing holes and that sucks. thanks for the feedback & godspeed my friend

 

[Bassguy64]

Re: Mercury 150 Preformance issue

Thanks Faztbullet, I was hoping to hear something like that, as for the holeshot I hope not, at present when you mat the Hot foot the entire boat jumps out of the lake ( about 6" between prop and water) my buddy took a great shot of it from the dock my nads arent big enough to launch higher thanks again friend. Late

 

[j_martin]

Re: Mercury 150 Preformance issue

Trim it down before you mash the footfeed. It'll jump up flatter and safer, and also get going faster. Usual move is to mash the throttle and the trim up switch at the same time.

John