F115 timing belt tension.

[poppywillow]

My local boat yard have just fitted a new f115 to a friends boat, They are saying the timing belt is very slack (they are not experienced outboard chaps).

What tension should be on the belt. As I say the engine is brand new, never been started, well by us anyway. So we dont know whether to call the engine suppliers to inspect the motor. Any info would be good.

Regards
Martin
England.

[BaileysBoat]

New as in brand new 0 hours? What year?

At any rate the F115 timing belt uses a self tensioning assembly same part number F75 to F115 1999 on up. Needs to be replaced every 1000 hours.

If you manualy rotate the engine the wrong way the tensioner will be defeated and the belt will seem loose.

[poppywillow]

Thank you for the reply, The engine is a 2010/2011 and has 0hrs I will pass the information on you supplied.

Any further ino will be most appreciated.

Martin

[rodbolt17]

actually, yours is NOT self adjusting.
its fixed with a spring.
to adjust it loosen the 14mm hex bolt,rotate the engine in its normal direction about 1/4 turn.
then tighten the adjuster lock bolt(14mm) and is good.
the F150 and up use automatic adjusters.

[BaileysBoat]

Thanks for checking up on me Rodbolt. I was looking at the parts list and trying to cross with my F150 manual. Good lesson for all: get a factory manual.

[poppywillow]

Hi thanks for the info. Does anyone have a PDF workshop manual for the F115, would be very useful.

Regards
martin.

[rodbolt17]

if you had to ask how to adjust belt tension on that engine it means you really dont know anything about it.
means the work shop manual wont help much as it doesnt really describe anything.
your F115 is a simple speed density EFI setup that runs in an open loop. no O2 sensor.
the manual is avalible from yamaha on PDF/DVD.
myself, I much prefer the paper copy. its easier to handle.
my suggestion would be to use google.
use key words like speed density EFI theory.
learn what each sensor in the system does,why its there and what happens if its not.
there really isnt much difference in the theoretical operation of any of the speed density open loop systems.

[melaatik]

I noticed that my F100 -06 is having slight vibration in the belt while the engine is running. The deflection of the belt is notable, something about 10-15mm when tested by hand while engine not running

Does the Rodbolts advise above regarding manual tensioning of the belt apply also to this Yam?