Yahama F50 TLRD Is a DOG

[150aintenuff]

just ran a F50 EFI yahama on a little catermaran and boy was it a dog... is that because it was new and still in breakin or what??? on a "1100 lb fully loaded hull" (manufactures claim of total load) it would only turn a 12 P prop and prop calculators say should run a 16-17 what gives... was it weak or are the new midrange motorsnot quite the power on the cowl???? the 2 stroke on the same hull turns the same RPM with a 17 and 1.83 gears ( merc) so why not this 4 stroke... just wondering if anyone knows why the yammy wasnt up to par with the merc of same HP on the same hull (weight theoretical identical)...

[Capt.Insane-o]

welcome to 4 strokeville. How many hours are on it now?

[150aintenuff]

maybe 2 hrs.. not my boat i just finished the rigging and setup...

[Capt.Insane-o]

I'm not sure if there is a break in mode on those now, call kenesaw and ask.......but they have to be propped to run right at the limiter with a light load. I rigged a carb 50 on a flatbottom john at was not overly impressed with the performance.

[150aintenuff]

there didnt appear to be... i ran it the 2 hours and was not at all impressed.. i first propped it with a 16 that was equal pitch of the merc 50 hp that was the main test boat (44mph@6100) and could only turn 5400 light and so i used the shipped out 12P and bangged the limmiter light @ 6350 so I left it as it was my only other option.... (new dealership... not a lot of parts supply yet) with 3 adults it was at 5700-5900 at neutral trim... but as it was a demo i didnt really run it hard out to see if I could get more... I reccommended a 13 P stainless as the new owners will be using it as a jet ski chaser and will mostly be 1 person in the boat.... but I was unimpressed...

I was fully expecting the ECM to limmit my set up time but it didnt so i dont think there is a breakin like the merc V6 has where you only get a few short WOT runs to get it right...

[Gordie Miller]

I don't think it matters that it's a 4 stroke, if it's THAT bad you got other issues.

[150aintenuff]

exactlly my thoughts... but I wasnt allowed to tweek the setup... I dosted another thread over in the setup section that discusses the boats setup.. but so far no responces yet.... the new one that came in today is going to have the same problems... the factory pre rigged it and used the wrong lower holes so motor height is fixed in a position about 1.5" lower than the merc powered hull and without sending the boat back there is nothiong I can do about it.... unless I get a glass guy to fix the other lower holes...

[Gordie Miller]

to fill the incorrect holes. Put the motor at the correct height to start with. I put a 60 Merc 4 stroke on a 15' Whaler and that bad boy ran 45+ MPH all day long, just as a reference

[JW]

I'd never try to turn a new motor to the rev limiter

[150aintenuff]

I was proping it.. only reason to run to limmiter was to ensure full RPM range and prop was right.... after initial proping i went through the "propper breakin" with the owner... I am the rigger who finished the boat. just to clarify IT IS NOT MY BOAT...

gordie.. we just took delivery of a red boat Identical of the other one in this thread.. sent it back to factory with my demands to repair and send engine back off of the boat because not only was it 1.5" low it was off center by 1/2 " and canted to the right 1/2" as well... totally crooked mounted... so rather than try to fix their mistake we sent it back and I am going to fully rig the next one MYSELF and then maybe with a 16P stainless it will run like they should.. hopping to see 45+ as well not 32...

I will try to get some pics this week end so you all can see what i am talking about.