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Heck 2 buck is probably one of if not the most nalligabell person on this site when it comes to omc triples and boat racing in general. Hell he's probably built more omc triple engines than any of us have ever seen. Great guy with great advice.

And Kevin has built and raced his fair share also. Butt one thing about him you should no is he is a amazing machinist and owns a world class machine shop your talking about a guy thar hits 1/2 though tolerances all day.

I no both these guys personal and they will go above and beyond to help out. Now I am not saying you wrong.
Butt I thought you should no who these people are that you talking too.

That being said I hope your right cut well all would like bigger carbs.

Perhaps you could measure it with a boar gauge and post a pic of you doing it to show use.

Also why do you want to putt bigger carbs on?
You haven't made any performance mods that warent changing the carbs. You should be able to get your best performance by optimizing you jets to your running conditions.

Adding larger carbs to a stock up modified motor can actually make the motor run worse.the air entering þhrough the carb and venturi can become stagnant with the larger carb and venturi size thus the engine tends to be more lazy. If you won't to run big carbs you should make the appropriate mods to you motor first in tuner,cut head and porting.

Sorry ment to say unmodified motor

Thanks for the kind words MGR. I got distracted from paperwork and felt like doing some trolling... in a boat forum... hah...

MGR these carbs are not for modified motors, these are just what makes the difference between a 60 and a 70hp.
there is nothing at all other than the carbs between a 60hp and 70hp oval port engine.
so i was expecting a fair increase in power right through the range. it didn't happen on top end.


as for porting and modifying exhaust yes maybe it needs to breathe a bit better to get more .
this is why i have been asking question about the oval port motors, its only hec2buck who seems to know anything about them so far.

plenty of people think they know, then fall flat when talking about porting as they forget its oval and not bridged.

who on here knows how far the top of the oval exhaust is from the top of the block in stock form ? probably just a few
how many people on here have actually fully modified a oval port 56 ? possibly 1 or 2.

What I was saying is you should optimization you jetting with you 1 1/4 70hp carbs.
Not the other carbs we haven't seen before. And as fare as porting gone just clean the ports up and port match between all cylinders . Have you changed the reeds yet?

You can make a big difference if you cut the head, install some composite reeds, check and adjust timing and re jet for optimum performance

Timing is already spot on. Reeds wont give me any more top end rpm. Go back and read everything. I did NOT have 1.25 70 carbs, i had 60hp carbs.
Cutting the head also will not give more rpm so ive been told on here. So theres 4 things already in place or not worth doing at the moment. Once i know exactly what will give extra top end, then other bits get done at same time.
But nobody seems to want to say they have cut the ports in a oval port .
Have you got a 1994 onwards oval port or worked on one ?

For your application, I'd pass on all the time and effort for porting, tuner etc. replace the oval port with a 90 yamaha and your done.

If we are just dreaming here and having a conversation carry on

Shush with your logic!