Broke down... twice!

[Flex]

Merry Xmas all.

Bit of a novel here sorry.. but I had a terrible day on water today.

Headed offshore today and found one of my motors (twin f115's yamahas) would not go above 3000rpm. Suspected throttle issue.
Back to ramp/home. Stripped down air intake butterfly and found it was Jammed due to previous owner gunking lanolin grease all over motor. Cleaned it up and back to marina before lunch to try again.motor ran like a dream.. for 20km..

Got 20km out and stopped to chase school of tuna
Went to restart and horrid grinding noise on start up.
Pulled cowl and fly wheel had come off! With motor fault code 13 up on dash.
Bolted it back down, restarted motor ok with no fault code.
but now motor runs bit rough below 4000rpm with a slight 'miss'. Most noticable at around 2000rpm and only just noticeable at idle.

No noticeable loss of power but hard to tell with twins. Got home fine sitting on 4000rpm no worries.with no fault codes. But def not right.
At home, pulled flywheel and had also broken key. Bugger.
No damage to stator visible. Swapped stator and flywheel with other motor and no difference(stator works fine on other motor)

So unless it's an unrelated issue like bad injector/pump etc. which I'll start checking next few days.
I'm chasing bit if knowledge. Could I have partially blown up a coil pack but dropping flywheel from stator while running?

I'm worried the entire crank may have jammed for split second and I've got valve damage? I doubt this as timing belt is new and Undamaged. But never say never.

Also can a sticky air intake butterfly valve cause rough running?

Any ideas?
Cheers

[up the creek]

i got no mechanical wisdom to offer, but just want to say what a sh*t day. nothing worse then a motor break down let alone 2 or 3 things happening, hope you get it fixed soon and get back out there, have a good 1..

[scottar]

First thing I would do is verify the timing.

[FisHard]

First thing I would do is verify the timing.
i believe this all happened in one day.
;)

[PixieAU]

Boom-tish!

[Fed]

Did you put a new flywheel key in it and torque it down properly Flex?

[Flex]

Checked timing marks and they all line up perfectly. No damage to timing belt.
The timing is controlled electronically via ecu.
There are two drive shaft proxy sensors used for timing I believe. Possible the steel plate that runs past proxys has moved. How far out woukd it have to be to notice difference?

[Spaniard_King]

5 degrees you would see a difference. Had an engine recently where the cam timing was correct but the ignition timing was out causing the ecu to not control the idle air control valve properly.

so if the cam timing is correct, it would be worth checking the ignition timing, we found this to be very erratic.

handy to have that second engine for diagnostics

[Flex]

Did you put a new flywheel key in it and torque it down properly Flex?
Used the old key and torqued down.

Rookie mistake. I think I'll reseat it with valve paste and lock tight it this time.

[Fed]

While you have got it off check the magnets if it has them on the inner ring, needless to say I have no idea what's in there.

Very important though don't forget to torque the other motor's flywheel, the key is only for alignment, it's the taper that stops it spinning. I don't know the torque spec but a Merc 115 4 is 140 Ft/Lbs so it will be similar, you don't want to damage the crank.

Edit: Unless it's called for in the manual & I doubt it is then I wouldn't use any Loctite on the taper.
Normally clean & dry.
Unless someone here (HI Garry) actually knows this is not something you want to fool with.

[Flex]

5 degrees you would see a difference. Had an engine recently where the cam timing was correct but the ignition timing was out causing the ecu to not control the idle air control valve properly.

so if the cam timing is correct, it would be worth checking the ignition timing, we found this to be very erratic.

handy to have that second engine for diagnostics

Cheers for that,
I assume you'd need diag equipment to check that? Might need to take it in to dealer
I've since found out that after a code 13 fault restricts motor to fixed timing. Wondering if the fault needs clearing from ecu before returning to normal?

[Fed]

It looks like a value added extra...
http://www.thehulltruth.com/boating-forum/387520-twin-yam-f115-s-slight-bump-sandy-bottom-flywheels-loosen-up-later-offshore-2.html

[scottar]

i believe this all happened in one day.
;)

LOL. Time for two new engines.......

[Flex]

I was meaning to use lock tight on the threaded bolt on top only. Not the taper, cheers for the link you posted Fred. Seems Yamaha had a recall on flywheel nuts at some stage aswell. I'll see if I can find model details.
My motors are 2004 models. So with a little bit of rust on the flywheel collar id imagine id have to clean it up to have fresh steel on steel. No damage to magnet or stator as I swapped to other motor and ran fine.

Ive bought the diagnostic software. time to have some fun!
Cheers

[Noelm]

Most devices that fit on a taper require a clean dry surface, no grease, loctite or anything else, there was a recall at one time, but I can't remember why?

[Fed]

Guessing your motors are the same as the ones supplied to Mercury.

This is from the link above, aside from the loosen & re-torque procedure change I have highlighted the part that you need to think hard about.

This is an excerpt from the 2001 Merc S.B.....


Service Procedure Changed
The service procedure is changed when the flywheel is removed from the crankshaft. The
new procedure is to retorque the flywheel nut after running at idle for 10 minutes. This new
procedure is to be used on all 115 EFI four stroke models whenever the need to remove the
flywheel has occurred. The service manual will be changed at the next revision.
Procedure:
IMPORTANT: Clean flywheel/crankshaft taper with solvent and assemble dry.
1. Remove all lubricants from the crankshaft taper and flywheel taper with alcohol.
2. Place the flywheel key into the slot.
3. Install the flywheel.
IMPORTANT: Do not allow oil to contact the flywheel taper or the crankshaft taper.
4. Lube the top of the flywheel nut washer carefully and sparingly with four stroke outboard
oil.
5. Lube the flywheel nut threads carefully and sparingly with four stroke outboard oil.
6. Install the washer and nut.
7. Hold flywheel using flywheel holder (91-83163M) and tighten nut to the specified torque
with a torque wrench to 140 lb-ft.
8. Run the engine at idle for 10 minutes.
9. Loosen the flywheel nut. DO NOT remove the flywheel.
10. Retorque the flywheel nut to 140 lb-ft. with a torque wrench.






Failure to follow this procedure may result in a loose flywheel condition.

Passive aggressive manual writing engineers.
They tell you exactly what to do but don't tell you why or the consequences of doing it wrong.
You'd think they would say NOTE: Oiling the bottom of the washer or the crankshaft threads can lead to oil getting to the taper joint which can cause the taper to slip. Using no oil can give incorrect torque settings.

The subtle difference between oil on the nut threads & oil on the crankshaft threads.
Engineers, got to love 'em but having said that it's all there laid out for you.

[Noelm]

Lubricating a taper fit can cause various problems, one pretty major one is actually splitting the flywheel from the extreme force applied when the nut is tightened, next, the flywheel will not lock on the taper and become loose, remember the key is only there to facilitate correct alignment, it does not stop the flywheel from turning on the shaft, that's the tapers job, there is a couple of others too.

[Noelm]

I guess I should add, the same applies to the nut, if the manufacturer says it should be dry, then that's how it goes on, if they specify a bit of oil, do it, same goes for loctite, use what is specified, lots of nuts and bolts holding all sorts of "stuff" matter little how they are tightened, but things like flywheel, rod bolts, and stuff like that are critical.

[Flex]

Thanks heaps fred/noelm
That's a fairly detailed procedure.
After more reading I've learned there was a spate of loose flywheels during early release of merc/yammies for that model.
Still can't find recall details if at all applicable for my model though.

I was aware they key shouldn't be load driven and is only for location purposes. I didn't expect it to be such an issue that an exact procedure was needed. I cleaned drive shaft, wheel and used no lube at all on shaft.
Manual doesn't talk about lock tight on nut at all. But can't hurt to put a little on top surely?as long as it doesn't creep into gap I'd flywheel?

As to fault code 13. I believe the motor returns to fixed timing after fault and can cause rough running. Does this code stay in the ecu until cleared? It's no longer flashing on display but maybe it needs an aknowledgement to reset.
Be a few weeks before I coukd get diagnostics on it.
I might just swap ecu with other motor

[lembo]

Hi guys,i own half the boat with flex and have been working on motor today, still not fixed but going through the process of elimination.
so the flywheel popped off breaking the woodruff key. I think it may have broke when we went to start , the starter lifting the flywheel and spinning it causing movement and the broken key. that's the easy fix.
The hard bit is ever since it has been running like crap it sounds like its missing on acceleration. it idles ok (not perfect but ok) but when I accelerate it misses and jumps around a bit.
Because were running twins I have swapped lots of parts and still haven't found a fix.
I have changed stator and flywheel thinking it got damaged and wasn't enducing much voltage to give a good spark
changed both coils and all spark plugs
swapped ecu's thinking the error code (code 13) was playing up the timing ( code apperared when fault first happened but has since cleared it was a pulser coil error)

Anyone recommend where I can be looking at next ? and know how a flywheel coming loose can cause coughing and spluttering on acceleration ? And also does the timing of the motor change with load/acceleration ?
bloody thing is doing my head in, il be heading out soon to swap rectifiers, maybe its just coincidence that this error is happening after the flywheel fault.

[Noelm]

The timing changes, but is controlled by the ECU, however, it must have a "base" setting of some sort, also the crank position sensor might have been moved or something like that, interfering with injector firing, even some wiring might have got damaged maybe? Mind you, it could be simply a second fault that happened at the wrong time!

[lembo]

yeah I was thinking the crank position sensor may have moved causing timing to be out but ive had a look and it all seems to be lined up, and the only movement was between the bit that got caught (flywheel) and crank shaft which is what broke the woodruff key.i cant see a way that the timing could of slipped and gone out. so now tomorrow I will be pulling fuel injectors out and giving them a clean. I also read that these f115s can "make oil" and when the oil is too high is can foam up and foul the bottom injector up a bit. oil is right at top of dipstick so i will drop a bit of oil to middle of dipstick and try clean everything. plus il test my fuel rail pressure.
Any recommendations no matter how stupid I'm willing to try.
il keep at it tomorrow and I should get it going just in time for this wind to blowup !!

[Spaniard_King]

compare the ignition timing on both engine by using a timing light?

[Fed]

The silence is deafening.
Anyway, https://www.scribd.com/doc/46608601/Yamaha-Outboard-F115-Service-Repair-Manual
Check 5-11 and 5-12 for alignment marks (Part #16)
Did you swap pulsers?
Good luck with your project.

[Flex]

Thanks heaps for the info.
We are still working on the issue.
My brother has been battling away at it in between rain clouds.
Swapped pulsar coil aswell as fly wheel. Tested coil with multi meter and all ok. Pretty much swapped every electrical component to do with ignition.

Aside testing ignition timing with a light. I think electrical has been eliminated now.
I'm thinking it's a unrelated coincidental fault. Onto fuel system checks/clean.
Then onto throttle body adjustments if needed.

Could just take it in to a dealer. But that's no fun is it!

[scottar]

Could just take it in to a dealer. But that's no fun is it!

LOL. Been there done that, only to find out I cost myself a shitload by messing with shit I thought I knew something about - but really didn't so it turned out. That said, I still have a go - I just make sure I know a bit about whatever I am messing with - easier these days with the intermanet.

[Fed]

Check the compression before you spend too much time on it.

[Flex]

Thanks everyone for your input.

An update for anyone who may be interested. Motor is now fixed!!

Got software off ebay for $60. this is so handy to have! everyone should have the software for their motor IMO. No fault codes showing though when we plugged it in.
While waiting for software to arrive , Pulled all injectors and flushed/back flushed, pulled VST tank off and cleaned it out. Pulled low pressure pump and checked for leaks. Checked Throttle sensor, Cleaned IAC, checked spark. compression tested motors all good.

Put injectors back in and the motor ran great above 1000RPM. still a bit rough at idle though.

Software has the ability to function test the IAC(idle control valve) both statically and dynamically. Turns out the IAC wasn't operating correctly and the throttle position sensor was out of adjustment slightly. ECU sends signal to IAC to open to a certain % but has no feedback to say its actually open/closed.

Pulled all flex conduit/lecky tape off the cables going to the IAC/TPS and found 2 cables slightly rubbed through which I would assume touch on occasion. Fixed these up and all back together.

Did a throttle body sync and Throttle sensor set and motor runs like a dream now!.

Will still pull off injectors to get them flow matched though just to be sure.

As often when you have multiple faults at the same time that are unrelated, it makes it very interesting fault finding.

So issue was blocked injector and electrical at the same time!

See you on the water!

[Noelm]

Jesus, my crystal ball was on track...see post 21.

[Flex]

Yeah Noel need to hire your crystal ball out:)
On the positive side I'm now a f115 yamaha pro mechanic!..lol


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[feral cat]

Just reading this now, i have the merc 115's with f115 powerheads on them. The software program is good and being able sync both motors to idle/run the same is even better. Something to watch is the butterfly screws that sync the 2 pairs of butterfly"s vibrating loose and giving them a rough idle. Allso make sure you have the plastic covers all over the harness, Had an a problem just recently a 4.5v sensor wire coming out of ECU rubbing on block causing engine to cut out. In the manual it sais to clean injectors every 100hrs. Mine need it by then as well. Allso i have developed a problem with vapour entering the intake after a hard run sometimes, and only sometimes..... If you encounter this put to full throttle which cuts out injectors and ECU goes into flood start mode, few cranks and it fires up. (Only happens when running 5500rpm for over 2hrs straight and i cut engine before cooling further down, fuel boils in the VST and vapours go into intake causing it flood on start up.) Something to be wary of with these motors. Making oil is commonly from a stuck open thermastat, Check every 100hrs as well. There good motors mate.

[Flex]

Thanks for the info feral. I didn't know about the vapour issue. The position of the VST is a bit of pain being buried between block and in take aswell.
Be putting spiral wrap on the cable looms I think.
I'm aware of the making oil issue. But any idea of how much oil and what time frame this can happen?



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[Noelm]

Making oil is common in lots of brands and models, it's simply caused by running too cold (thermostats) or prolonged low speed with no higher speeds, or in rare cases, a sticking injector, the oil just gets diluted with fuel, and has a very distinctive petrol smell when the dipstick is removed.

[docaster]

Hi Flex, if you don't mind me asking where did you get the diagnostic cable and software from? From the US?
Thanks
John

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[Flex]

Got it off ebay. Mine came from Lithuania of all places. Was delivered inside 7 days too. Works a treat.

[feral cat]

Another thing flex to check when hooked up to your laptop is where the IAC valve is positioned when warmed up and idleing. The ECU toggles the ground wire to make little adjustments and if its not happy the ECU will keep toggling thinking it needs to make more adjustments and effectively eventually smoke your ECU. Typically the ECU calls for about 47 to 68% open at warmed up idle, Any less and you have excess air entering the intake. TPS sensor must be reading .700 volts with both butterfly screws undone.
Just something to think about mate because i learnt the hard way.lol
Happy boating.

[Flex]

Thanks Feral,

I was reading about this issue on the hull thruth forums. Do you know if it cooks the whole ECU or just the internal contact to the IAC? The IAC closes at full throttle?
I tested mine with the software and it seems to work fine. I'm yet to do a TPS sensor adjustment/throttle sync. In process of making a harness for testing.

[feral cat]

The bloke at the time i gave a look at said it was the TPS out of adjustment which eventually burnt out ECU. (Was like it when i bought these motors) so god knows how long it had been out of adjustment. But i don't know for sure.....I got the shits with him and took back my motors..... Also the ECU had another issue which the high pressure fuel pump would stop once warmed up, Turned out to be the Ecu as well.
No need to make a harness, Your program will tell you TPS settings. Just make sure the TPS is reading .7 with both screws undone and go from there. Mine run at idle reading .728 to .730 with the IAC valve open 50 to 55%. From there the ECU will toggle the ground wire to make minor adjustments to achieve an idle speed of 750rpm. Plus or minus. Once you do it once you should'nt have to touch them again, mine had been fiddled with prior to me buying them so i had to learn.lol