EC300 suddenly low on power but then returns back to normal
 

Hi,

I have a EC300 2008. With some strange enginge behavior. A couple of times i have experience suddenly power loss and a change in engine sound. First I thought i lost the silencer or the exhaus gasket. But they semes to be fine.

Then i notice that it can go back to normal if I do a couple of more runs. You can listen to the sound i the clips on you tube.

The first is very loud with bad power output. https://youtu.be/82lFPtz-hPY

The other is normal power. https://youtu.be/NRMCXnJ5rKQ

Between these clips i only did a 100m run.

What do you think can cause this?

Regards Mika

Check the power valve. It's sticking.

Ok, thank you!

When it is sticking can it easy be lubricated from the small hatch to get it to work or do you think the entire power valve need to be removed and greased or changed?

Regards Mika

It likely needs to be removed and have all the carbon buildup removed form it. The part of the cylinder that houses it is also likely to be fouled with build up as well. htis would be a logical point to do a top end, clean the power valve and such and start fresh.