Hello everyone,
I'm having problems with my new air filter. I bought a TwinShock foam air filter and coated it with oil as described in the manual. That was probably a bit much, after a test ride the oil dripped out of the air filter box. In addition, the engine speed did not rise above 4000 rpm and I had no power.
I rinsed out the air filter with plenty of brake cleaner, but the result did not change.
Without the air filter I have good power.

Before I adjust the carburetor, I would like to rule out the possibility that it is the air filter. So i ordered a new filter and will check again.
Do the new air filters no longer need to be oiled? I saw on the forum that a TwinShock air filter oil is recommended, but without oil you should have the best pull, or am I wrong? I won't be driving on dusty roads for the time being.

It ran fine with the old air filter, but it also had a 2 cm/ ~1 inch hole...
 

I guess it does point to the filter being too restrictive if itwas ok before. Not sure about washing it out in brake cleaner though.
Rightly or wrongly i just wash them in petrol & let them dry out before oiling.
I squeeze them until prettywell can't squeeze anymore oil up in the squeeze & try to leave it evenly destributed.
Mind you i just use 20/50 oil mostly or something cheap. But proper filter fluid should stay suspended when the inflamable thinning stuff evaporates.
I shouldn't even mention the exhaust but if its restricted & 'only just reving out clean before', then any increased restriction of the new filter could make a more noticable difference than normal.
Inlets to the airbox clear & not obstructed by something under the seat etc.

I bought a new filter from Yamaha for my RT3 and used Bel Ray foam filter oil and it runs fine. Worked it in thoroughly and squeezed the excess out. Runs fine. If yours runs good without a filter, maybe jetting issue?

"I bought a new filter from Yamaha for my RT3 and used Bel Ray foam filter oil and it runs fine. Worked it in thoroughly and squeezed the excess out. Runs fine. If yours runs good without a filter, maybe jetting issue?"

Just a FYI on this particular filter, and that is that it now comes pre-oiled from Yamaha.

I noticed this when buying one for my RT2 in about 2018 (dry), and buying the same part for my DT3 in 2023 (oiled). Change of part number suffix from -00 to -01 reflects this.

You've got a lot of potential issues here. 

1. If you meant "Twin Air" and not "TwinShock" filter oil, you need to follow the directions for the oil.  It's a very thin liquid you apply to the foam and then squeeze out the excess.  Finally, you let it dry overnight.  It's a very "dry" oil and will not run off or drip. 

2.  If you used another oil, you don't know how to oil a filter and squeeze (not wring) out the excess.  It's easy to over oil and it sounds like you did that badly. 

3.  Using "brake clean", you've almost certainly PERMANENTLY DESTROYED the air filter element.

Yesterday I washed out the filter with ethanol. Unfortunately i had no gas here and want to give it a try. But I have already ordered a new filter and will also buy the TwinAIR oil to avoid mistakes.

Next time I'll use gasoline to wash it out.

Now that the filter is clear, the bike is revving properly and runs as I think it should.
A jetting problem can't be ruled out, but now that it's running I'll keep an eye on the spark plug pattern and see.

So thank you for your help and new tipps!

Just double check that the new filter doesn't come pre-oiled.