Yamaha 2001 F115 four stroke won't idle - help!

[ronreece]

I have a 2001 F115 Yamaha four stroke with 850 hours on it that was idling rough.



Figured it was time for a little overdue maintenance.



I've done most of the work in the past on all my motors with very few issues.



Decided to change:



The timing belt and tensioner. Everything came off and went back in without a hitch. Located TDC on flywheel and lined up the arrows on the cam gears. Replaced belt. Adjusted tensioner. Smooth as butter.



Replaced old thermostat with a shiny new one. Smooth as butter.



Replaced the four fuel injectors. Everything came out easy-peasy and went back together again (checked the pressure in the fuel rail and had a bit over 40 psi - right in spec). Smooth as butter.



Removed the idle control valve and soaked it for two days (completely submerged) in Marvel Mystery Oil (after reading here that this method has worked for other guys). Replaced the old O ring and reinstalled the valve. Seemed smooth as butter.



Took the boat down to the water and initially it fired right up, but then it died out within moments. I was able to put the shifter in neutral and with about half throttle, was able to get the engine started, and and it ran smooth at 2000 rpm. However, every time I dropped it back down into idle/neutral, the engine would die out. Also wasn't able to get it started again in neutral.



WTF???



Could it be that soaking the idle control valve in the Marvel Mystery Oil screwed it up? I'm scratching my head thinking that - simply because it won't idle. BTW, I tried disconnecting the ICV while I had it running at high idle, but didn't notice a change - or when it was reconnected - just died out again.



Help!

[ronreece]

Hummm,

I used a universal pulley holder with two pins that went down through the flywheel holes (to help hold the flywheel-and was a major pain in ass, when trying to pop the flywheel off the shaft with the flywheel puller).

After a long battle, the flywheel popped off, and underneath, I discovered that I had damaged one of the copper wires on the stator with the flywheel holder (must have went in too far).

Now I'm wondering if that may be the reason the engine won't idle?

Any feedback on that thought?

[ronreece]

Here's a pic of the broken wire

[greasyshaft]

It's the lighting coil. it's ****ed

[ronreece]

What's the "lighting coil"? If the wire's broken will it make the engine not idle and hard to start (it seems to run fine in neutral at 1500+ rpm).

[greasyshaft]

charges the battery. I should just call it a stator.
The ignition system on your outboard(TCI) requires battery power unlike typical CDI systems.
Have you noticed any change in battery voltage on your gauges?
I don't know if a damaged lighting coil can cause stalling but the system will eventually run out of charge. either way the lighting coil will need replacing.
Can you here the ISC valve reset when you shut the engine off.?

[sailorboy]

just replaced 2 stators on F225a's very pricey part.was even back ordered for a while.
i order to hold the fly wheel still found a scrap of 3/16 aluminum and a drill... works great

[ronreece]

just replaced 2 stators on F225a's very pricey part.was even back ordered for a while.
i order to hold the fly wheel still found a scrap of 3/16 aluminum and a drill... works great

That's a great idea. The f'ing flywheel was literally welded (rusted) to the crankshaft. It took forever to get it separated!

[jamesgibbs1983@gmail.com]

I have a similar issue, 02 f115 won’t idle it chugs and dies. If I turn up idle screw to around 1100 it will run but will still miss. Had injectors sent out for a rebuild. New plugs new filters vst was changed last summer. It runs fine at higher rpm and has plenty of power just won’t idle. Please help don’t wanna put it in the shop they are all weeks out.

[Keithbaja]

You can't rebuild injectors,, only recondition. Replace seals and filter and end cap (guard) Ck spray pattern. Ck for leaks. Ck flow rate..Sale.... The pintle and seat can not be reworked. Also windings. I've seen many fresh "recondition injectors" fail miserable after a short time of restall. But, then again. I have experienced them lasting a long time. Its "rough" to pony up for new injectors. Anyone here know about FICHT injectors. OMG !!

[Keithbaja]

BTW ck for vacuum leaks at lumby idle is a gold standard

[rodker11]

hes my 2 cents
i brought a f115 with 750hrs
i had two problems
first the motor would stall and not have a dependable idle i replaced iac valve and problem was fixed for about 10hrs
then the motor would fast idle at 1500rpm at intermitant times,i checked the tps voltage at idle which was reading high.
as no one in my vacinity had a new tps i pulled mine off and undid the factory seal with a soldering iron and opened it up
the tps had a globual of water in it upsetting the resestence given,i dryed it out and refitted,all problems solved
i have since fitted a new tps
in my opinion
if i have a simalar problem in the future i will replace iac and tps as a unit
PS the tps is not a sealed unit and is vented to the manifold,if not used often any moisture in the manifold ends up in the tps