[QUOTE=Nice Pair;4490404]I've been running twin outboards for about 15 years on different boats and have seen the motor with the counter rotating lower consistently turning 200+/_ rpms slower.

I've always believed the difference to be the way the lower handles the thrust. (front tapered cone bearing R.H.) (flat needle thrust bearing L.H.)
The counter rotating also runs hotter and will "burn" the oil faster.

x2 as ive been racing merc v6s since 1981
and believe the same as with gearcase running on reverse gear for counter
the differences in the bearing,the heavier carrier,gears thrusting propshaft towards bullet as prop is pushing it the same direction
causing that bearing to be loaded harder and thus does burn the gearcase oil faster,,,,,
2 motors never run exact same so always put stronger powerhead on counter
adjust throttles on clock with a tad of slack so at speed throttles are even to even rpms
can even tweak a tad more load on the clock prop to sync in the 2 motors

It's nice to see running @ that speed that you wear your safety gear , Not to many would do that when running there boat to the limit , GREAT job :)

How did you know Steve? :confused: You always catch onto my tricks......

Thanks, when I'm out testing by myself, and no buddy on the water in another boat, I'm extra cautious. I have all my race gear, so I figure it's stupid not to wear it - even if a chute jacket is a little overkill at only 120mph.

Now to get this thread back on track, Steve just ran 115 today in his beautiful blue bomber! Congrats Steve, now post up on here to tell everyone about it. :eating:

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Thanx Dale for staying on top of things. Ha. I ran out today and ran this 115mph at 6940. Took a while to get there. Was great to finally break thru. It was with my Merc 33 pitch props. It was in the 70s here today and I was carrying about 50 gallons on board so its not a totally unrealistic number. What you can't see in the vessel view is my port motor is somewhere around 7100rpm and my starboard is around 6800 rpm. The port doesn't have much more to give and the starboard is lagging behind once again by roughly 300rpms. As I said before the marina is gonna start to try and figure out why that is happening. If I gained that back I would think I would gain a couple mph for low maybe 3mph would be great. Wont know until if or when that happens. If I had two strong motors Id bet they both be running on the limiters at 117 or 118mph. Nice to dream about. Ha. My Dewalds get back to me the end of this week. Dave took a little bit off the Dia and cup which he had left a good amount in. Im sure they will have to go back to him at least once more before they are tweaked enough. He's thinking the speed will come with the rpm increase. Once again my Dewalds are 34 pitch 15.25 dia and 20 degree rake.

That's great Steve. Hope they find something. It will be interesting to see also if the dewalds are 300rpm down also. I had a set of props once that one of them were way out of whack once they put them on an anylizer and checked the pitch of every blade.
It is possible they could have changed when the blades are thin.

Hey Ron. Already ran the Dewalds once thats why theyre goin back to be trimmed a bit. Need more rpms. When i ran them they also showed a difference in rpms. Not as much cause i couldnt up to the high end range. They start to separate at 6000rpms and it gets worse the higher you go. My girlfriend videod the vesselview a little while ago and we stopped it at different speeds to see where its off. At the top one motor was at 7100 and other at 6800 roughly.

maybe he can shave down the weaker motor prop a bit to get it to come up 200 or 300 rpm vs the strong motor prop ?

[QUOTE=johnmiffco;4490459]Hey John Thanx for the info, It does make sense. I believe when Skater tested that last 318 the motors were turning very close to one another. Much closer than my 300rpm difference. At any rate Im gonna have it looked at because my mechanic said that 300rpms is a bit much to be off. He is a racer and throttles for one of the I/O Cat teams for years now. Thanx again, Steve.

no problem
there is very little rpm differences between the 2 gearcases,50-100 window winding up
when get to limiters usually same
mainly counter breaks down oil faster
the 300rpm is close to a pitch difference,,,,,
so yea change props and if same rpm variable and have em checked,,,,,,

ur boat is awesome,,,,and spending some time to figure it out is a + for every1
im redoing a 97 28 right now and putting the lil 2.5s on it off my 27 ex
so may have to put all 3 on to keep up with these new hulls with 400s,,,,,,,lol

Got my Dewalds back the other day. Weather is real nice here right now. Gonna get them on and give them a run next day or so. Ill post when I get some numbers on they're first tune in. Im sure they'll have to go back at least once more. Steve.

Still have not had the pleasure of seeing this boat in person... Keep us posted on how it runs with the new props.. good luck .

Whats does one of these 318's go for in price range?

IIRC 350k to 400k.

The grey and black 318 that ran 122mph cost over $400k with the TAOD paint job.

Man I almost feel guilty makes mine a bargain.

sold! :)

Hmm, maybe a gently used 368 better way to go

I was told the buyer of the $400k+ 318 replaced his 40 Skater and 32 Skater with that 318. I'm not much different - I sold my 28 Skater and am re-rigging my 30 w/ 400Rs (from Sterlings/ASDSs) to happily go back to just one 30' boat with outboards. Pete said most of the customers for these 318/400R boats are all coming from bigger inboard boats. And I always said the exact same thing you said, until you realize all the negatives that go along with that used, big-power 368 for the same price as a new, warrantied 318/400R.

Amen brother.
Deep pockets needed and full time mechanic. Otherwise OB only way to go.

I have his 3212. Glad he did the trade.

You were swamped today. We will be in Saturday. Need to talk full Fusion systems.

The 368 OB could be a real game changer.....especially if Mercury is coming out with 450/500/550 who knows down the road.

I don't think I will ever get rid of my 40 though.....just use it a lot less. Hammering in that boat is like nothing else I've ever done and it never gets old.

Just have one of the others in the booth grab me.
Thanks

Interesting, thanks for the info

Hey guys anybody reading this I actually started a new thread about the 318 and its continued dial in. There was a powerhead that was bad since day one and was replaced with a new one. Sorry I forgot about this post and maybe should have continued it here. You can find some results closer to my end pursuits there with new powerhead and different size props. Thanx Steve.