Yamaha Tech Publications

[rowboater]

I have a Yamaha Clymers service manual but do not find it a lot of help.Was hoping to find a troubleshooting chart online or a suggestion where to by the factory maintenance maual for the best price.My motor is a 1997 Yamaha C115TRLV.Thanks for any help.

 

[NBE]

Re: Yamaha Tech Publications

Your local Yamaha dealer can get you one or you can try the Yamaha website as you can order from there too. Don't know if these are the best prices though. I got mine from the dealer for the same price as the website without the shipping costs.

 

[rodbolt]

Re: Yamaha Tech Publications

what are you attempting to troubleshoot?
the 04 and 05 marine tech guides have some wonderful engine condition worksheets that if ANYONE follows them will have found most any problem by the time the last question is answerted, however most techs enjoy floundering about.

 

[rowboater]

Re: Yamaha Tech Publications

what are you attempting to troubleshoot?
the 04 and 05 marine tech guides have some wonderful engine condition worksheets that if ANYONE follows them will have found most any problem by the time the last question is answerted, however most techs enjoy floundering about.

 

[rowboater]

Re: Yamaha Tech Publications

The syptoms are @ idle the engine RPM would fluctuate and the motor would "backfire/burp" thru the exhaust bad enough to stall the motor out.I changed the fuel filter (Yamaha) and swapped out plugs with no help.Took the boat for a test drive and it runs up @ higher RPM's without any loss of power,but still would stall out eventually @ idle.Thought the problem might be with the pilot screw adjustments.Clymers call for lightly seating pilot screw and then 3/8-7/8 turns out.Did notice when one of the pilot screws is almost completely seated the "burp/backfire" went away and the engine idled smoothly.Wondered how unusual for such a problem to just show up is and if almost seating the on adj screw is an indication of a bigger problem.

 

[rodbolt]

Re: Yamaha Tech Publications

yep
the pilot needles on those carbs DO NOT adjust the air to fuel ratio. that is controled by the pilot air jet and the idle fuel jet. all the needle does is control how much of the mix enters the intake tract.
that backfire is just that, however it cannot escape the reeds to come out of the carb so it tries to push the bottom of the piston in the wrong direction. an explosion is an explosion and the crank really does not care which side of the piston its on. most lily you have a clogged idle fuel jet,bad pump diaphram or bad fuel bowl gasket. time for some complete fuel system maint tactics.
what your describing is commonly known as a "lean" sneeze and can blow fuel pumps and cause bearing and piston failure if not corrected.

 

[rowboater]

Re: Yamaha Tech Publications

Rodbolt,
Thanks for the brief operating discription and the direction as to which way to go towards fixing the problem.One thing I run into using the Clymers manuals is their terminology.Their is no "idle fuel jet' in their exploded view of the carburetor but am I correct in assuming the "pilot jet" would be the same thing ? Also would the "fuel bowl gasket" be the the gasket on the "float chamber"? I have been reading up on fuel pumps and diaphram operation as these items are original parts and are suspect and am probably going to be purchasing a carb repair kit.Thanks for the term "lean sneeze" there are many references to such conditions as mine that came up in the search feature.

 

[rowboater]

Re: Yamaha Tech Publications

Rodbolt,
Checked the fuel pump today with a vacuum gauge and ended up finding a torn diaphram.Just wanted to say thanks again for the direction.It's great that your willing to take the time and share your knowledge with so many.I sorta believe in karma and gotta feel you have a lot of good that should come your way.

 

[rodbolt]

Re: Yamaha Tech Publications

no worries, hope ya learned a bit about your machine.
good luck.
yes pilot fuel jet and idle jet are the same, same as pilot air and idle air.
yes the terminology gets a bit squirrely whith jinglish, ya outta try it with volvo penta´s swinglish.