Outboard Coughs to a stop

[Hightower]

Evinrude DI 150 (FICHT)

Yesterday whilst out with Whisper fishing I had a couple of anomalies happen which I can't explain.

We started out from Portsmouth and gave the engine a good run looking for mackerel. We then tried some drift fishing though Langston fairway which is a 6 knot speed limit, after the second drift we were cruising back up the channel and the engine got lumpy and gradually dies on us (kind of like fuel starvation). A prime of the fuel bulb which felt like it had a little bit of air in and was definitely soft and after pushing the ignition key for chock off we went again. This happened again later on too. Same circumstances as before, all at low speed, low RPM's. No hint of trouble at WOT or higher speeds.

When we recovered we noticed a smell of petrol coming from under the cowling. I've had a check this morning and there is a little bit of fuel at the bottom of the airbox, it's like it's dribbled out of the Port side lower air intake. This has never append before, although it is common to get a little two stroke oil out of the lower starboard air intake.

I ran the outboard this morning on the flush muffs and it ran faultlessly without any sign of a fuel leak.

I'm not convinced it's an engine fault and after squeezing the primer bulb for 5 mins there appears to be no leakage after the bulb which is placed after the water separator filter.

I'm a bit confused as I thought that fuel starvation problems would appear worse at higher RPM not at 1500 RPM. Any suggestions?

[whisper]

I really don't know too much about outboards but a complete guess would be unburnt fuel in one cylinder due to no or erratic ignition in that cylinder at low rpm?

I would check the plug to see what colour it is?

[Pikey Dave]

Could be a few things. Dodgy ignition (coil) as suggested by whisper, could be the low pressure fuel pump, this runs on pressure pulses from the crankcase. If the hose is restricted there might not be enough "oomph" to pump the fuel at low RPM. If the diaphragm is holed in the pump, it'll allow fuel into the crankcase. I'd pull the plugs out for starters & see wot u got.

[Peter_C]

Originally Posted by Hightower

When we recovered we noticed a smell of petrol coming from under the cowling. I've had a check this morning and there is a little bit of fuel at the bottom of the airbox, it's like it's dribbled out of the Port side lower air intake.

Fuel leak = BAD! Fix the major issue and you might fix your running problem too. Might want to keep your fire extinguisher handy too

[Hightower]

I've had her running a good bit yesterday and there's no sign of a fuel leak anywhere. Not even out the bottom air inlet even after tilting up. So the petrol bit might be a seperate issue. I did find some air in the top of the Delphi water separator filter which could only have been introduced up stream of the filter, so something to look at next weekend. I didn't get a chance to pull plugs so will ha e a look later this week.

[9D280]

I guess if it's a FICT DI is that acronym what I think it is - Direct Injection? I didn't think the FICTs were quite that high tech, but open to conrrection.

If it is Direct into he Cyl, how is the fuel getting into the inlet chamber in the first place?

Assuming a more "conventional" fuel injection, does it have a pressure regulator? (keeps the fuel system pressure at a constant delta across the tiny orifice at the business end of the injector)

If it's fuel injected into the inlet manifold / inlet port, that pressure will drop at low speed (closed throttle = more of a vacuum on the engine side of the throttle) and if there is a leak in the vac hose, the pressure relief valve won't open so readily, as it will see something more akin to "ambient pressure", so resulting in a higher fuel pressure therefore excess fuel being squirted in. (engine management assumes a constant pressure difference, so opens the injector for a specified time based o nthe delta-P it has been programmed for). Would explain both a too rich mix (if that's what you find) and excess fuel........

[GordyP]

Used to have a couple of Fichts, sure I remember ther being a small amount of 2 stroke oil that would leak out the air box when the engines were lifted up, it was just a couple of drops.

[Chris]

When my plugs got passed the 120 hour mark on my E-tec it started to run roughly at low RPM's and would not idle for long.

Plugs are critical on DI engines and they dont last so i would change 'em regardless.

[Dhf]

Confession.... I've been having the same problem same engine, when in speed restricted erea's, although not completly stall on the go, It's more a case of not wanting to restart after a few miles at tickover, that is untill I engage nute and give it a quick blast upon starting, then it runs smooth, I've been told by an Evinrude mech they just don't like low rpm's and will have a splutter now an then, but they'll happily run high rpm's all day, I also have a small amount of oil/fuel that collects inside casing, but can't find where from exactly. I reckon these engines are more suited for racing, which of cause we don't want on a fishing trip, but on the other hand after a day not catching much, it don't half put a smile on ur face when blasting WOT! and exceleration is sumut else. so i'm happy with mine for now.

[Hightower]

Originally Posted by Chris

When my plugs got passed the 120 hour mark on my E-tec it started to run roughly at low RPM's and would not idle for long.

Plugs are critical on DI engines and they dont last so i would change 'em regardless.

Plugs were new in June so not that many hours. I change them at 80hrs regardless.

[Hightower]

I'd like to see a drawing for this outboard mapping out how the induction and exhaust is constructed. Perhaps a visit to the BRP website later this evening.

[Hightower]

Originally Posted by Dragonhawk ficht

Confession.... I've been having the same problem same engine, when in speed restricted erea's, although not completly stall on the go, It's more a case of not wanting to restart after a few miles at tickover, that is untill I engage nute and give it a quick blast upon starting, then it runs smooth, I've been told by an Evinrude mech they just don't like low rpm's and will have a splutter now an then, but they'll happily run high rpm's all day, I also have a small amount of oil/fuel that collects inside casing, but can't find where from exactly. I reckon these engines are more suited for racing, which of cause we don't want on a fishing trip, but on the other hand after a day not catching much, it don't half put a smile on ur face when blasting WOT! and exceleration is sumut else. so i'm happy with mine for now.

I've always had some sort of rough running at lower speed after prolonged use. Never bothered me to be honest. However it has never died on me before. I'm going to bypass the RACOR filter in the short term and see if I can get rid of the air, that'll eliminate one potential problem.

with the petrol in the airbox, I'm not going to panic as it was only a little bit, but would like a better understanding how these 2 stroke DI engines work so i can determine where it's coming from.

[mister p]

I'd suggest swapping coils first and then check pump diaphragms. I hope it's as simple as this.
The pic is an evening return from the IoW into Southampton.
Nought to do with thread I know, but pleasant I hope.

[Pikey Dave]

Have you got the diagnostic software & cable?

[Hightower]

Originally Posted by Pikey Dave

Have you got the diagnostic software & cable?

Yes I have, just haven't had a chance to use it yet. There were no audible alarms on board when it happened.

[Pikey Dave]

Originally Posted by Hightower

Yes I have, just haven't had a chance to use it yet. There were no audible alarms on board when it happened.

The software should allow you to shut down individual ignition coils & injectors, it will help narrow down the problem. I'm not sure what the functionality is with the FICHT engines though.

[Hightower]

I'm not sure I've quite got to the stage of having to go in to the software and shut stuff down yet but will bear it in mind for the future. I'll simplify the fuel system to reduce the risk of air entering for the time being and see if I get a repeat of Saturday's problems.

As for the fuel in the airbox. This has never happened before to my knowledge, so could it be that the injector squirted a measure of fuel in to the cylinder nanoseconds before I switched off the ignition, so remained unburnt and dribbled out the throttle when the outboard was tilted up?

[Chris]

All you need is one plug to be a bit dodgy and it will lower the RPM enough for a stall. I would just try a new set of plugs to be sure. You can always put the old ones back and save the new set for the next service.

Did you index the plugs when you last changed them?

Chris

[9D280]

Originally Posted by Dragonhawk ficht

I've been told by an Evinrude mech they just don't like low rpm's and will have a splutter now an then, but they'll happily run high rpm's all day,

Ahhhhh so it's like a high tech version of a premix engine then?

[Hightower]

Originally Posted by Chris

All you need is one plug to be a bit dodgy and it will lower the RPM enough for a stall. I would just try a new set of plugs to be sure. You can always put the old ones back and save the new set for the next service.

Did you index the plugs when you last changed them?

Chris

They were indexed, I had to buy another 7 plugs to get two to fit properly.

I'm already familiar with what the engine runs like one plug down, when I had it serviced in 2009 the technician forgot to fully push one of the HT leads fully home . It didn't stall at tick over, in fact you'd never have known it was running on 5. Stick it in gear and you knew something wasn't right. So I'm pretty sure that isn't the case this time around.