Yamaha EF2000IS smoking after storage

I'm having smoke issues with a 2nd hand EF2000 generator that's rarely used and would appreciate any pointers.

It was bought 2nd hand in 2012 and I think 2010 model. I rarely use it, maybe once or twice a year. I think last time fired up was Jan 2015 and it was fine then and each time before.

Fastforward to this week, I've gone to check it over. It fired up first pull, then started smoking, gradually at first then smoking like a mofo. Then it surged, esp worse on eco mode. Smoke was white, pretty thick, and smelt like burnt oil.

I shut it down, and figured oil may have absorbed some moisture and overfilled. Upon opening the oil drain a whole lot of thin oil poured out, smelt like petrol was in there. Ok, that might explain it. So I refilled with 5100 to the indicated level. Restarted it.

Both symptoms of smoking and surging were same as before. I pulled it apart and pulled the carb to bits and found the pilot jet was blocked, cleaned it and checked the float height. Also checked the vent over the valve cover was clear and put back together.

No surging! But still smoking like a mofo. And it only smokes after 5-10s but just gets worse and worse.

Checked the plug - not wet, but dark choc brown. Gap was spot on.

Any ideas why this is still smoking? And why after a period of doing nothing? Thanks heaps,

 

carb leaked fuel into the oil thinning it out. possibly some of that is still in the engine seeping into the cylinder, like on the valves etc
id say let it run and see what happens after an extended period of time not that the carb clean and the oil is good.

 

Sounds like a stuck piston ring not sealing well.

 

Probably did some engine damage with the fuel soaked oil.

 

Thanks guys. I couldn't see anything apart from top of piston looking down spark plug hole, but it had an oily appearance.

I'll check oil again, run for another 10mins then go to plan B, hopefully nothing too serious.

 

check compression, if its a stuck ring,(it happens, should roll stuff over couple times a month) drain oil, pull plug , drown it in diesel. keep doing that until the diesel does not easily run past piston and out the drain.

 

Nice one, I'll check on the weekend. Thanks for the tip.

 

If compression checks out fine, the float needle in the carb may be damaged enough to allow fuel to fill the crankcase again. Cleaning doesn't always cure all the issues.