Last night i put in to do some night fishing .. running up river i noticed the motor sounded different.. turned around and stopped motor.. it was getting dark..had a slight knocking..eased back towards ramp had to run the motor was easy on it but i was still 6 miles or so out.. it got louder...trolled the last 2 miles or so.. no power loss or anything.. motor ran great last 3 times it was out.. 1 pulling tube and 2 fishing trips during the past 2 week..
I did some reading on past article and came across one where someone had a knock and rodbolt had explained to put pistons at TDC and move 30 degrees and listen and feel for movent when pushing on piston .. noticed #3 had some movement...
I've got to get a manual and compression gauge..to recheck compression
it was 120# across the board when i had carbs redone 1 month ago..
what can i expect when i start to tear down ?.. i'm pretty mechanically inclined on car engines and so just never had to work on an outboard.
is it possible to just replace that particular bearing and check the crank for any kind of damage? i'd like to get out as cheap as possible..but still have it be dependable.. kind of a cliche
__________________
fishings' not life or death.... its more important...
I've got a couple questions more..
what could have caused this to happen so as i dont fix it and not fix the cause and just have it happen again maybe worse? could pulling a tube with it? Its got a 19 pitch prop on it..always no trouble out of the whole but could we be putting to much stress on the motor and need to go down in pitch.. i'd be more than happy to trade off some top end when i fish if i know that its not going to kill the motor when we do watersports
__________________
fishings' not life or death.... its more important...
You might want to look at the oil in the lower unit, a bad lower unit can really fool you with some knocking noises, check to see if there is metal particles or a burnt smell before you tear the engine apart!
Just remember the engine is 20 years old and even a Yamaha can have wear after that long a time.Rodbolt's test is very accurate. Rebuild it right and it may go another 20. Obviously all of the pistons ,rings and pins as well as pin bearings have an equal amount of wear or very close to it.
Get a factory service manual and many people are capable of rebuilding.
One of these days justintime will get out of mechanic school and go to work servicing these units and dealing with customers. He will only try his supposed solution once.
Just remember the engine is 20 years old and even a Yamaha can have wear after that long a time.Rodbolt's test is very accurate. Rebuild it right and it may go another 20. Obviously all of the pistons ,rings and pins as well as pin bearings have an equal amount of wear or very close to it.
Get a factory service manual and many people are capable of rebuilding.
One of these days justintime will get out of mechanic school and go to work servicing these units and dealing with customers. He will only try his supposed solution once.
ray
i have been working since may
i just give little tid bits of info on here
if i see the motor, that is a whole nother story
87 yamaha 115 knocking
HUMAN BUILT = HUMAN FIXED
CERTIFIED MARINE TECH
Re: 87 yamaha 115 knocking
Linear Mode
