Hello Everyone,

Hope I can ask my question here;

I've had my Johnson 40 (MDL: BJ40TLENJ, S/N: G03108531) for just about a year now, and all the sudden (3 days ago) I was cruising along the river when, when I reduced speed from cruise to near-idle, it started smoking badly (something it hasn't done before); lots of white/lightblue-ish smoke coming out of the upper exhaust (is it called "idle exhaust"?) from the smell, it is definately smoke and not steam.

After playing around a bit, and scratching my head a lot, it appears that when I trimmed up with the prop just under water, after +/- 30 seconds 90% of the smoke is gone, but the moment I trim down, it's back again.

I am inclined to say that smoke-production reduces slightly at higher speeds, although I haven't been able to test at WOT due to speedrestrictions close to home.

I can't think of anything obvious; I have checked and cleaned the sparkplugs, which were not extremely polluted or anything, just "used" (QL78C, they're about 6 months old) and I cannot yet tell if she's using excessive amounts of oil as I have only run the engine for about 2-3 hours since this started. Oil used is XD30 which the dealer who serviced it last winter provided me with, it has been running on it for about 20 hours since service. With this service, a new fuelpump has been fitted as well.

Would any of you be able to give me any suggestions; things I would best check to try and trace back to the cause of this sudden change?

All advice would be much appreciated.

Thank you,

Ardjan Stam
Holland

[Edit] Sorry; I forgot to add, just reading through all these forums I realise I probably don't exactly "fit the crowd" equipmentwise, but from all the site's I've come across this one definately contains a lot of valuable information; I'm hoping someone could spare a minute for me..


Modified by Ardjan at 1:40 PM 7/20/2006