E-tec Spark Plugs

Chris Murray · 10 September 2006, 19:02

My E-tec 250 seemed a bit lumpy at under 2000 RPM yesterday, by the end of the day. It has now done approx 40 hours.

Is it time to change the plugs?

On my previous engine (5.7 litre V8 inboard) I would have said clean or change the plugs, but these seem to foul up at different stages, when it is considered (by Evinrude techies) to be normal.

I've not looked at them but it certainly "feels" like the plugs may need attention.

Any thoughts?

Thanks.

Chris.

P.S. We were fully airborne quite a lot - not sure if this is significant.

J S · 10 September 2006, 22:22

Hi Chris

I work on a humber 10m charter rib in the summer with 2 e-tec 250's on and we have found that bye the end of a 8hr day about 4hrs crusing at 25knts and the rest at slow speeds the engines start to shudder at low speeds we found the solution was to run at WOT or close to it for about 5 minutes at the end of the day to burn of the spark plugs. After a burn off the shuddering stops.

Hope this helps

James

BogMonster · 10 September 2006, 22:55

You get a similar thing to that pottering around with big petrol engines in cars. If I have just been running round town for a week or two in the Discovery without seeing many revs, if you give it a bootful of throttle to say 4000rpm in the first couple of gears, you get quite a noticeable amount of smoke as the crud burns off the plugs then it is fine after that. I think they call it an "Italian service"

My Johnson goes lumpy and coughs and farts and jumps around under about 2000rpm after a very short time idling, as soon as you open it up over about 2500rpm again it clears in a few seconds, so I put it down to gunge on the plugs. It just won't run smoothly at idle/low revs for any time at all. I just sort of assumed it was a "2 stroke thing"....?

jyasaki · 11 September 2006, 08:18

Hmmm. Maybe running something like Yamaha's Ring Free or an equivalent (of which there are many) to help minimize carbon build-up?

jky

PeterR · 11 September 2006, 10:09

Before adding anything i would check with evenrude so as not to invalidate any warenty.Rod Bowers at their head office would be the guy to ask.

Seaharrier · 11 September 2006, 11:02

Chris,

What oil are you using?

Lostboy · 11 September 2006, 11:50

It's interesting as my Rude (an older Ficht design) does exactly the same thing! It sounds a little rough at idle/low revs, almost like a mis-fire, if it's been run for extended periods but then immediately clears with a bit of throttle (not WOT but anything above 4k).

RIVA · 11 September 2006, 12:00

just so you are aware ? on the 250 etec if you do a lot of slow running there is a adaption takes muinites

you change the pins ask a dealer and they will know about it

j

MarkM · 11 September 2006, 19:41

When using a modern two stroke direct injection engine you should know the following.
After running at low revs for hours I rev my Evinrude 250 DI up, to clean the engine.
A few times a year I use a carbon guard in about 100 litres of fuel to clean up the inside of the enginge. You should see what comes out of the exhaust.

Chris Murray · 11 September 2006, 22:55

That's encouraging, so it might just be slow running then?

Actually, most of my running would have been higher than 4000 RPM, yet the unstable low speed behaviour was pretty well immediately afterwards.

I shall be out again for much of Wednesday, so I shall give it some "welly" then and see what difference it makes. Hopefully, this will resolve the problem.

I am using the XD 100 oil and I have had the modification done - at my insistance - by no less than Rod himself. It's nice to see someone doing a job with such attention to detail - he even counted the pins that had been removed, to make sure that numbers fitted equalled numbers removed!

Apart from this, and the occasional stall immediately after high speed running (which alsways restarts immediately) the engine is pretty impressive.

Thanks for your thoughts!

Regards,

Chris.

quinquarimarine · 11 September 2006, 23:02

We must have fitted and in many cases used dozens of the big ETECS by now so have a good handle on their ways.

Agreed, like any 2 stroke a good burn after a lot of tick over will help. A common problem can be the belief that putting a bigger engine on but only running it a mid revs will be better. Not always the case.

Carbon guard (sold by Evinrude) can be sprayed into the air manifold and if having done a lot of low rev work can make a huge difference. Cost retail about £7 a can.

As per other post a deflector pin on the injector can be fitted by an approved Evinrude dealer.

Lastly if changing your own plugs always re-gap before fitting (never assume they are correct). From memory 25tho on the Etec plugs. Most important though is that they must be alinged correctly with the injector.

Cheers

John
www.quinquari.co.uk

dctucker · 12 September 2006, 04:56

Quote:

Originally Posted by quinquarimarine

We must have fitted and in many cases used dozens of the big ETECS by now so have a good handle on their ways.

Agreed, like any 2 stroke a good burn after a lot of tick over will help. A common problem can be the belief that putting a bigger engine on but only running it a mid revs will be better. Not always the case.

Carbon guard (sold by Evinrude) can be sprayed into the air manifold and if having done a lot of low rev work can make a huge difference. Cost retail about £7 a can.

As per other post a deflector pin on the injector can be fitted by an approved Evinrude dealer.

Lastly if changing your own plugs always re-gap before fitting (never assume they are correct). From memory 25tho on the Etec plugs. Most important though is that they must be alinged correctly with the injector.

Cheers

John
www.quinquari.co.uk

Can you expand on what these injector pins are for, and what they do? Also, what do you mean by aligninging the plugs with the injectors?

I may be on the verge of ordering a 90 ETEC for my Searider, and I'd like to know what I'm getting into!

Thanks.

Seaharrier · 12 September 2006, 07:21

Apart from this, and the occasional stall immediately after high speed running ...

I used to have that problem. When entering the harbour at low speed the engine used to be running unstable at idle, and often stalled. Every time the engine did this, is was easy to restart it. This problem never happened when the engine was cold.

Paul

IBWET · 12 September 2006, 08:03

where are these pins in your engine and how do they change the running?

codprawn · 12 September 2006, 14:04

http://www.boatsetup.com/PlgIndex.pd...ark%20plugs%22

Explains it all - funnily enough we used to have to do the same trick on some of the 2 stroke model racing engines.