2017 Express 350 yamaha's

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zzzingpow

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Engines surveyed with decent compression, decarbonize by yamaha tech, compression went up good numbers....so, went out full fuel, water 2 persons. Boat was bow up, wouldn't plane. Upon return recalibrate trim tabs.
Tech finished new charts, AIS, etc...sea trial to calibrate auto pilot and the boat was at 5300rpm's, only 12 knots acheived....any ideas what's going on? Calm seas good weather...
 
zzzingpow said:
Engines surveyed with decent compression, decarbonize by yamaha tech, compression went up good numbers....so, went out full fuel, water 2 persons. Boat was bow up, wouldn't plane. Upon return recalibrate trim tabs.
Tech finished new charts, AIS, etc...sea trial to calibrate auto pilot and the boat was at 5300rpm's, only 12 knots acheived....any ideas what's going on? Calm seas good weather...
Click to expand...
Spun hubs on the props maybe? Something definitely ain’t right there. I have a 2018 with 300s in San Diego and I don’t use trim tabs at all to get on plane. Only use tabs if there’s a lot of weight on one side of the boat or running head into some crappy seas.
 
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A spun prop should be easy to check. Jam the throttle forward and if the revs immediately go high but the boat doesn't accelerate, the prop is spun. That said, I wouldn't expect both props to be spun at the same time. It is possible that the motors have very wrong size props.
As mentioned, how does the hull look?
Can you verify that the tabs can be fully retracted and if so, try your test again with no tabs and motors straight down.
Are the motors original to the boat?
 
who is calling the shots here? the boat ran bow up and they wanted to recalibrate the trim tabs? tabs can either do nothing or bring the bow down. what were the rpms on the first trial? was it acting like a dirty bottom or spun hubs then as well?

if the engines are spinning quick and you are getting no performance AND both engines are acting the same, i would guess a very dirty hull bottom (marine growth). if the engines are acting different, then a spun hub. it is possible, that both hubs are spun, but that would be an odd coincidence or show that one hub spun, was neglected, put additional strain on the other engine and hub, then that hub failed. either way, bottom condition and hubs are very easy to check and whoever is "managing" this sale should have already been able to figure this out before you as the potential buyer could go online and ask.

this is giving me the feeling of a poorly maintained boat and/or an owner that doesnt care about things being right.
 
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1. 330 or 370?
2. i cruised at 3800 to 4000 with my '09 330 with 350's. never a problem.

good luck, ron
 
Put engines in gear starboard rocks back n forth approx 1", port spins free.
THATS HOW TO CHECK.
Remove port prop and perform exact as aforementioned process.
Port shaft responds same as Starboard, Rick's back n forth approx 1"....spun hub it is....
 
Ekea said:
who is calling the shots here? the boat ran bow up and they wanted to recalibrate the trim tabs? tabs can either do nothing or bring the bow down. what were the rpms on the first trial? was it acting like a dirty bottom or spun hubs then as well?

if the engines are spinning quick and you are getting no performance AND both engines are acting the same, i would guess a very dirty hull bottom (marine growth). if the engines are acting different, then a spun hub. it is possible, that both hubs are spun, but that would be an odd coincidence or show that one hub spun, was neglected, put additional strain on the other engine and hub, then that hub failed. either way, bottom condition and hubs are very easy to check and whoever is "managing" this sale should have already been able to figure this out before you as the potential buyer could go online and ask.

this is giving me the feeling of a poorly maintained boat and/or an owner that doesnt care about things being right.
Click to expand...
Your feelings are semi incorrect, previous owner did neglect however I had vessel surveyed and mechanically surveyed by yam tech prior to delivery, appreciate the input.
Port prop hub spun starboard good to go
 
GET SOME said:
Spun hubs on the props maybe? Something definitely ain’t right there. I have a 2018 with 300s in San Diego and I don’t use trim tabs at all to get on plane. Only use tabs if there’s a lot of weight on one side of the boat or running head into some crappy seas.
Click to expand...
You sir are correct. Spun port hub. Thank you, I didn't think of that. You saved me some $$$$
 
Very nice...love the rod rack. Definitely next on the to do.....just ordered new hub (got 2 just in case) out of west coast marine san diego be here tomorrow am.
My rubber was chewed up innermost part. Thanks again for sharing the knowledge. See you on the water,
ALI'I KAIA HuntingtonBeach,
 
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zzzingpow said:
Very nice...love the rod rack. Definitely next on the to do.....just ordered new hub (got 2 just in case) out of west coast marine san diego be here tomorrow am.
My rubber was chewed up innermost part. Thanks again for sharing the knowledge. See you on the water,
ALI'I KAIA HuntingtonBeach,
Click to expand...
Any chance you've better pics of rod rack? How do you reach them?
Had a guy today measure for rack as yours in stainless however reaching rods is damn near impossible, lowering rack interfered with sunshade....I'm open for ideas
 
zzzingpow said:
Any chance you've better pics of rod rack? How do you reach them?
Had a guy today measure for rack as yours in stainless however reaching rods is damn near impossible, lowering rack interfered with sunshade....I'm open for ideas
Click to expand...
You aren’t wrong on the access issues. I’m 6’ 5” and have issues. We installed a 100 gallon bait tank so you can stand on that and access everything. I also had a custom tower fabricated so I can be there driving and spotting fish and handing rods down to guys.
 

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GET SOME said:
You aren’t wrong on the access issues. I’m 6’ 5” and have issues. We installed a 100 gallon bait tank so you can stand on that and access everything. I also had a custom tower fabricated so I can be there driving and spotting fish and handing rods down to guys.
Click to expand...
 

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