F250BTUR Bad Rattle

msdw375

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May 31, 2010
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I've got an 08 Yamaha F250BTUR with new digital controls. Engine purs perfectly in neutral. Right when I kick into forward or backwards only at very low RPM the noise in the video happens. Once I get up on plane It does not make the noise and operates normally. I have serviced the lower unit (oil, water pump). Nothing abnormal with the oil when LU was serviced. Prop is perfect and no issue with the hub. Lower unit shaft is normal. It sounds like something is slipping somewhere but only right when I come out of neutral....runs great otherwise...ideas?
 

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99yam40

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does not sound like lower unit problem to me,
it goes into gear just fine.
does it keep making that noise while idling along, or is it just some seconds after putting into gear ?
 

msdw375

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does not sound like lower unit problem to me,
it goes into gear just fine.
does it keep making that noise while idling along, or is it just some seconds after putting into gear ?
It sounds like gears slipping and trying to catch. It's seems as if I accelerate past the noise. When it makes the noise if I give it more throttle it goes away. It doesn't make the noise every time either.
 

msdw375

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Adjust the shift stoke as not going fully into gear...
This is a digital controlled motor and binnacle. Wouldn't that be more of a mechanical controls issue? what would you adjust? The linkage between the engine and lower unit?
 

racerone

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I have to agree that it is not shifting into gear properly !----How that is done and how it is adjusted is out of may pay scale.-----Hurry to a shop that can adjust this for you.---If you let this go it may cost BIG $$$ beer tokens to fix it later.----You have to hope that it can be adjusted.----Looks like a new --" shift actuator " --- is a mere $3000 or so.------A classic case of over engineering in my opinion.
 
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99yam40

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who hooked up the new digital controls?
did this motor have that type of controls before the new ones?

Looks like the video shows it goes into gear cleanly, and starts pushing the boat.
if the clutch dogs were not engaging properly they would not hold at higher RPM.
is it possible that the controls are trying to bounce in and out quickly?
 
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msdw375

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The engine was recently bought used. The motor has always had digital controls but I'm not certain what the last boat's controls were. I believe this is a different lower unit than was original to the engine and the seller just changed it out prior to selling to me. The seller was the mechanic who did the install on my boat. Are you saying that the clutch dog may be incorrect? The engine only makes this noise when it's between 700 and 1200 or so RPM...once I'm above that, the noise is gone and the engine runs perfectly. It does not necessarily make the noise every time I throttle up either. Sometimes does and sometimes doesn't. Are you saying there are adjustments that can be made to the digital controls?
 

99yam40

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I have never messed with digital controls, so you will need to find someone familiar with that set up as far adjustments.
I would talk with the mechanic that installed it, letting him see and hear what is happening

I have no idea how the shift happens and if a bad connection could cause something like this.
just throwing out some thoughts I had
 
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