EC 300 smoking and bog down problems!!!
 

I have a 2017 ec 300 which has had several problems arise, all at once it appears. First coolant would periodically leak from the overflow, sometimes in excess, but the drip/pour would sometimes stop if the cap was removed and reapplied, so I ordered a new cap that had yet to arrive before I started billowing smoke one day. A service tech suggested malfunctioned cylinder head o rings, as in burning coolant, so I inspected the cylinder and piston, replaced all gaskets and o rings, and the problem still persists. The bike doesn?t fire immediately like it normally would, billows smoke, and is bogged badly/slow. The pipe also started splooging which has never happened at all on this bike. I?ve read about crank seals some, just don?t want to take anything else off and not have the precise answer and part. Before this happened bike ran practically flawlessly, no splooge, fouled plugs, excessive smoke, bog, nothing, ran like a champ!Any help would be appreciated! Gotta get this thing back ripping the woods up!

Any water in the spooge?

Is the spark hot and white/blue?

Maybe a little water just due to the consistency that it flowed out of the expansion chamber when cold. But the plug just looks normal, a little black, and smoke is thick and white, ran it after reassembly and it seemed to die down marginally at a higher rpm but power was still down, and immediately started smoking bad again after it revs down. Case oil is visibly low after that reassembly run, and still after engine cooled

Is the oil level lower than when you started? If so, it burns the gearbox oil due to a leak between the crancase and the gearbox, most likely due to a failed seal at the RH end of the crankshaft.

Black smoke normally indicates oil. White smoke normally indicates coolant.

It is possible you have a crack in the cylinder or a warped head. How did the cylinder base gasket look?

I think the case oil did lose some. And cylinder and head looked to be in good condition, base gasket was replaced. I guess I?ll drain the case and pull the right cover now. Any way the water pump could be causing anything related to this?

This is where I would be looking, as it appears your are pressurizing the coolant system and also burning coolant. I would be looking for a crack or a bad seal/gasket around the coolant passages.

Have you pulled the drain bolt at the bottom of the case for the crank just to see what's in there

Excellent Suggestion! I would do this first.