Yamaha F40 timing belt and mystery sound question

Tod Osier · #1 February 17th, 2005, 05:14 AM

I have a 2000 Yamaha F40 Manual trim and start and have a few questions that I havenÂ’t been able to get satisfactory answers from my dealer over the phone (but I havenÂ’t brought it in). The motor is still under warranty and has 180 hours on it. IÂ’ve read through the forum and searched the archives, and found a lot of good related info, but nothing specific to my questions.

Timing beltÂ… according to the owners and service manual my belt is loose. The service manual says that it should have 1 cm of play and it easily has 2-3 cm of play in the area where they say to test (the other side is much tighter). I talked to my dealer and they said that they have never changed a timing belt on a Yamaha F-anything. I find this hard to believe, given that I see on this forum that the recommended life is 1000 hours. I only have 180 hours on this motor, although it is several years old. The belt looks beautiful to me in terms of wear. Is this a problem? Would this repair be a warranty repair (I still have 4 months on the warranty)? If not, is it easy to do, and is there an aftermarket manual to get (since there is no way I would be able to do it based on the service manual I have)?

Second questionÂ… I have an intermittent noise that only occurs when the motor is warmed up, but does not always occur when the motor is warm and is noticeable at idle and mid throttle (I donÂ’t know if it goes away or is covered up by motor noise). It more commonly starts after the motor is restarted, rather then just while running, although it does just begin at times. The sound is Â“Swish, swish, swish,Â” not a squeal like a slipping belt, but it has a squeaking quality. It is obviously tied to the RPM of the motor and at idle is noticeably swish, swish, swish, but turns into more of a whine or squeaky sound at higher RPMs. IÂ’ve never been able to have it make the sound under conditions where I could really study where it is coming from, although in a day of fishing and shutting the motor off and on many times, and running at both WOT and idle it would likely appear once.

Thanks,

Tod

Triton II · #2 February 17th, 2005, 12:34 PM

G'day Tod, welcome to iboats. Resident outboard guru Rodbolt will no doubt jump to the rescue, but for my 0.02c worth, the belt can be tensioned by adjusting the idler pulley position (the manual tells you how to do this or get your dealer to do it) so it may be worth your while adjusting the pulley position to achieve the recommended 10mm of belt free play and see if the swishing and squeaking noises disappear. It's doubtful whether the adjustment (if you get the dealer to do it) would be under warranty as this is a routine maintenance item which is your responsibility.

If the noise remains after adjustment you've probably got a dirty bearing on either the idler pulley, the flywheel pulley or the cam pulley. Or it could be something else, but personally I'd start there. It'll be a job for a competent tech to fix, but Rodbolt will probably be able to help out here. Good luck.

rodbolt · #3 February 17th, 2005, 01:56 PM

thanks for the vote of confidence tritonII, wish I had as much.

Tod

have you been taking it in for regular service? the manual says 50hrsOR3 months,100hr OR 6 months,and 200 hours OR annually, thats once a year. timing belt inspection/replacement is every 200 hours OR once per year.same as the water pump,pressure valve,t=stat retorqueing the water covers. several others are covered as well.if you or your dealer is not carefully following the service guide quit wasting your money and run it till it quits. the timing belt is replaced at 1000 hours OR 5 years. WHICH EVER COMES FIRST. the internal anodes need to be inspected on the 100hr/6month schedule.

if you wish to maintain this motor follow the guide carefully

to adjust the timing belt tension you simply loosen the tensioner bolt and allow the spring to take upthe slack. torque the boilt back to 29 FT pounds. the torque is critical. the swish swish you hear is most likely the timing belt. its normal. but while you have the tensioner loose its easy to spin the idler and check for roughness or noise.

be aware most dealers gundeck the service. an easy way is to lightly paint the fastners that wil have to be checked with paint. then after the service see if the paint is marked

Tod Osier · #4 February 18th, 2005, 04:05 AM

First of all, thanks for the information.

On the tensioning of the belt, there is no idler or ability to tension the belt that I am able to see in the manual or on the engine (otherwise, I'd have done that myself). Maybe this is something very different than I am familiar with (like an invisible one?!?!), but all there is is a belt, a drive gear, and a driven gear. No tensioner or mention of one in the manual?

Thanks,

Tod

rodbolt · #5 February 18th, 2005, 04:35 AM

hello

my bad

.

I got your F40 confused with an F 80 that I am working on somehow. the F40 does not have a tensioner. if the belt deflection is out of spec its a replacement item. however the swishing sound I have heard before and its rather normal. starting with the B model they incorperate an auto decompersion device on the cam. but the rest of your service schedule should be followed. so far the F40 seems to be solid. even though I belive it uses the motorola ign and is built in conjunction with merc. if the belt is out of spec it may be a warrenty item. thats between you and your dealer. they may consider it a service item like a water pump.

Tod Osier · #6 February 18th, 2005, 04:41 AM

Thanks, for getting back to me. I'll talk to my dealer about replacement.

bigbrownbuku · #7 February 20th, 2005, 10:31 PM

yamaha belt test is push in only not side to side slop. all yamaha belts would be outta spec if this were true. so its 1cm at rest to push in firmly max distance. the noise you mention sounds like a dry driveshaft. lube on a fourstroke driveshaft isnt hanging around as long as 2strokes and will be a regular service item, especially in the area of the driveshaft support bushing.

Tod Osier · #8 February 22nd, 2005, 08:47 AM

BenC thanks. Belt will press in 2+ cm. Yes, as written, "play" is inappropriate (i.e., 2 cm of "play" would be in spec). I have not contacted my dealer re:warrenty coverage on belt.

Driveshaft would be lubricated via external grease fittings?

bigbrownbuku · #9 February 23rd, 2005, 09:59 PM

the driveshaft can only be lubed by removing the gearbox.

rodbolt · #10 February 24th, 2005, 03:37 AM

tod

if your F40 is an ML model (20") it has a bushing in the upper casing just above the water pump that willmake noise occasionally. the MS (15") does not have the bushing.thats is why we ask for model numbers.

but before ya get to worried disscuss the deflection with your dealer. I dont have my F40 manual in front of me now but your trying to measure the slack but dont push so hard you stretch it

.

Tod Osier · #11 February 24th, 2005, 04:44 AM

Sorry, it is an F40MSHY, so no bushing.

As far as the belt goesÂ… I'm sure it is out of spec, it is almost floppy and deflects out if spec with no force at all. I've talked to my dealer and they won't cover the belt replacement.

I am thinking of taking a bigger role in the routine maintenance and repairs of the motor and it looks like replacement of a timing belt shouldnÂ’t be too bad of a job. From the service manual it looks like it would entail removing the recoil starter, the flywheel magnet assembly and the stator, all of which look pretty straightforward and only require a couple specialized tools that I donÂ’tÂ’ have. Then again I could be wrong, any suggestions.

Are there any additional reference materials that would be useful for a non-factory-trained person that has the initiative to try and figure stuff out? Does a good aftermarket repair manual with more details exist?

I guess IÂ’ll need to find a source for Yamaha parts if I'm going to proceed? IÂ’ll read through the archives.