E-tec Spark Plugs

[Chris Murray]

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]

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]

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]

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]

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]

Chris,

What oil are you using?

[Lostboy]

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]

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]

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]

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.