Hello boaters, my engine arrived yet and here is couple of photos what i am gonna trying to do, i was dreamin' about first photo showed about how i want put pipes n exhaust sides but i saw i did stupid mistake and didnt ask and talk with bruce to rotate one of this exhaust port and now ashamed about myself but i wanted that you gentlemen see this and dont do same mistake as like as me, now first photos shows what i dream about it and last of them shows what i have , like tuned pipe flowers could you please tell me how i can fix my mistake ? Because engine flew to another country and have no chance to return back to FL and i really open all support from you guys, is it possible to change opposite side from left to right?

Sounds like you want to reverse one cylinder to have the pipes exit on both sides of the hull. I guess that's possible although I've never seen it on an inline twin. I really haven't been following these engines much though. Seems to me like you would for sure need a special header on the front cylinder so the pipe would clear the carb of the rear cylinder. That's the first thing. Second, I've seen guys flip the cylinder around on singles but that does involve modifications that I am not too familiar with. Maybe Scott will chime in here or other engine guys that have experience with this. Don't think the cylinder would be a happy as the other one being rotated 189 degrees with crank still turning in the same direction and ignition timing remaining the same??? At the very least there will be a drastic change in transfer port flow I would think, but like I said I have no real experience with this. Sorry I can't be of more help.


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I seen it done there is a Mystic Sport on Jims guy is doing with a rotated cylinder - I have done a few (Zenoah) and I would not recommend it

I would just change the headers pipes to some from BH Hansen

I sure some combo would clear - raise one up and one down or use a 90 degree and a #6 on back and should clear.

www.bhhanson.com/exhaust_systems%20&%20parts.htm

Randy

Seems to me that if you reverse one cylinder, one if them will lose performance because you'll be sucking hot air in through the carburator that is under the header.

Short and quick .... written this same thing in the long version so many times

Reversed Cylinder / Piston will have these things WRONG going on:
** Piston will thrust on power stroke against HOT exhaust side of cylinder being more prone to seizure issues.
** At the same time clearance between piston skirt at intake port opens up and the intake tract seals less efficiently and carb spit back increases and torque THAT cylinder produces will be less.
** Piston pin hole is manufactured with an off center offset for reasons of Piston/Rod angle dwell while at TDC. Turning piston 180* places offset on wrong side and sets dwell specs differently from other cylinder again upsetting equal power delivery between the two.

Many have done this and claim success .... where in reality engine runs ok but being they don't have the relativity of same engine running set up correctly ?
.... Ignorance is bliss I guess

Just the facts, do with it as you wish.
Regards,
Scott

Biggest problem is the heat in front of one of the carbs.
There are angled exhaust manifolds like that from MHZ. I think they are 15 degrees or so. They will give you enough clearance to use regular headers. Using one with a 100 or 105 degree header and one with 90 degree or 1 with 90 degree regular and a 90 degree 2'' offset and you are fine.

BTW: What kind of hardware is that? Nevver seen it before.

I would think the #10 and #11 header shown in the photo Randy put up would do an excellent job and still allow you to have both pipes on the same side.

This hull is obviously made for two parallel exhausts.
In my opinion you should not make any changes on a perfectly good engine. The issues about carbs and loss of power is not worth the trouble.
I would go for headers like no. 3 and pay a skillfull craftsman to get them "curled" in place right behind the engine to fit the parallel exhausts.
Costly? Maybe. But your boats hull is made for this. It gives a better balance, and it will look fantastic with the double exhausts!
Just make sure that you get reasonable access to the electronics below those two fat tubes.

Cheers! Woody.

Woody the hull may be made for port-starboard tune pipe exits but that does not mean the engine
chosen is. Scotts reply about rotating one cylinder should be held in high regard. Routing of pipe should be subject of header and pipe shape vs hull design.

Mercury.
Understand that I agree with Scott in this. The engine should stay as it is in order to perform to it's best.
My opinion is just that some curled pipes in order to get the exhaust pipes to fit parallel into the hull, maybe will be costly/difficult, but without stealing as much power as a rotated cylinder would.
Anyway this is also about looks, and for my part I would curl the header pipes to get both exhausts in perfect position.