New 40 Hp Yamaha

[Cantona]

Hi Guys,

Late last year i bought a new boat and ive been really enjoying getting back into fishing (Pittwater mostly).

Im having problems with the new yamaha 40HP. When trolling at low speeds for extended periods (1-2hrs) the engine will cut out. When i check the plugs they're covered in Oil, i clean them up and it runs great again.

Ive just had the motor serviced for the first time and the dealer said its quite common for the Yamaha to do this when new and it should settle down after a while. The motors done between 15-20 hrs. Initially when running the motor in i was using the suggested 50:1 oil mix and after that ive been using 100:1. Im using Yamalube Oil.

Im just wondering if anyones had this problem before? Is there anything i can do to stop the plugs from fouling? How long till the motor is run in? Its frustrating as cant troll as much as i want to.

cheers

Cantona

[dunc333]

dictch the 2 stroke and find a 4 stroke if you luv trawling,

[BFB]

I would not think that a new motor should be having this problem.

But the only true way to stop the plugs from fouling with a 2 stroke is every so often give the motor a good blast of revs whilst out trawling. This should help with it oiling up as it should clear any oil.

I used to have to do this with an old 2 stroke I had when I was using it for water skiing and whilst waiting for the skiiers to be ready it would oil up the plugs but that was 20 years ago.

[Geoff]

Im just wondering if anyones had this problem before? Is there anything i can do to stop the plugs from fouling? How long till the motor is run in? Its frustrating as cant troll as much as i want to.

cheers

Cantona

It can be a problem if trolling for this period of time with a 2s. The easiest fix , when on the water , is every half hour or so take it out of gear & give the throttle a few decent rev's to clear out ant unburnt oil from the cylinders / plugs then back into gear & continue on

It may be worth a call to Craig at Huett marine. XD50 or XD100 oil may be better suited to this type of situation

Geoff

[a boat]

Hi, any old tech engine like yours is not the best option for extended trolling unlike modern clean engines. That said a properly set-up carby 2-Stroke with good oil will be fine. My guess is your engine is not reaching correct low speed temp and therefore running cold and any technology outboard running cold at idle do not like it. Also as mentioned there are better oils for this sort of thing.

Cheers,

Huey.

[olitay]

trade it in mate and get a yammy 4 stroke... If its trolling that you do... your best getting a nice 4 stroke.

[Cantona]

All good feedback guys thanks!

I'll give these suggestions a go and hopefully see some improvement.

Cheers

[Gribble]

Are you running platinum plugs? My old 2 stroke motorbike would go four times as long without a plug change with the platinum plug than it did with conventional plugs, even on the bust-the-wallet-expensive motul and motorex 2 stroke oils.

Of course, consult the dealer first before changing anything as it could mess up your warranty or any work guarantees you have with them, and you dont want that with a nice, new motor.

PS, If anyone suggests to you to change the heat rating of the plug to something a bit warmer, dont do it. It can lead to hole-in-piston syndrome.