Yamaha Knocking Question

97century

Recruit
Joined
Sep 5, 2010
Messages
2
I just purchased a 1997 19 century center console, Has 97 Yamaha 130 Saltwater series. I have a knock under 1300 rpm, Sounds like to me it is a rod knock yet coming from under flywheel or so it sounds. I also have a overheat alarm above 3/4 throttle. Now I just pulled lower unit off to check impeller, Looks ok ( I will order and replace anyway as it is a year old and is time) T-stats also look like they have been replaced due to new t-stat covers. The cooling part I understand and will fix that issue, Weather i got to pull heads and clean passages. but the knocking worry's me, I pulled the lower off and started motor for 10 sec found I can not hear the noise at all, of course motor is a little louder without lower. So sounds like its a lower unit problem? P.S. Compression check is great.
 

Captn Dave

Petty Officer 2nd Class
Joined
Dec 5, 2001
Messages
176
Re: Yamaha Knocking Question

Did you replace the wave/spring type of washers on top of the water pump? Their purpose is to seat the drive shaft pinnion gear. If the drive shaft rides up it can produce the knocking sound.

Do a search for Rodbolts water pump repair procedure.
 

OdessaTim

Cadet
Joined
Mar 19, 2010
Messages
11
Re: Yamaha Knocking Question

I had a 97 225 Yamaha Saltwater Series that developed what I thought was a knock. Thought I was in for major repairs but a reliable and trusted mechanic found the problem to be the O2 sensor gasket blown out. Hope you find a similar "small dollar" issue.
 

97century

Recruit
Joined
Sep 5, 2010
Messages
2
Re: Yamaha Knocking Question

I did not mess with it yet although i took it out this weekend and i noticed it only makes the noise when it warms up like 3 min after running that worries me too, i need to warm it up then pull lower unit off and see if i hear it. thanks for your advice.... also still overheating over 1/2 throttle. I will order water pump and replace hopefully thats all thats wrong with the cooling part.
 

Captn Dave

Petty Officer 2nd Class
Joined
Dec 5, 2001
Messages
176
Re: Yamaha Knocking Question

mvitiello,

Not sure. That's a 4 stroke right? Might have completely different issues.

All I know is that after I replaced the water pumps on my engines, 1997 SWS II 200 HP, I had a momentary knock on in upon first starting up in the water. It went away after about a minute. I assumed it was the drive shaft riding up and hitting the bottom of the crank case. I had did a search and Rodbolt described the problem on another thread.

97 century,

Do a search for Rodbolt's water pump replacement procedure. It's very helpful. He tells you to replace those washers and I recommend it. Also the procedure for removing the shaft key which is a lot more difficult than it would seem.
 
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