Just buy the inline filter at your local hobby store. While there buy some Tygon tubing and replace all of your fuel lines and if it was me I would also replace the fuel tank. When you go to re-install the carb just make sure the bolts/screws that hold it on are not overtorqued. If you use loctite use the blue loctite not the red. Put only 1 drop on the bolt AFTER you have ran it through the spacer block. DO not let loctite touch anything that is plastic.

1 drop is enough dont overdo, the more loctite you use the harder it is to remove the carb in the future. Snug the attachment screws up snug but dont overtorque. Wish I had a torque value for you ,but if you have turned wrenches you know what I mean. Just snug it and monitor it. The loctite will do it's job.

You did what I would have done as far as cleaning the screens. As long as the diaphragm is not ruptured / torn you should be ok.

I believe that your engine may be running incorrectly due to the RPM figures you quoted earlier. Do not be afraid to adjust the needles. You will hear many ways to do this but here is my way. It may not be the way everyone else does it, but it works and works well. As an example I am on another thread and I dont believe anyone is turning the RPM that I am. And I am still running on the rich side.

So all that said here is a good way to tune for best performance. If someone here knows a better way speak up.

Start the engine (I use a test stand) you can do this on the plane but more difficult to do. Let it warm up for a few minutes.

Go to full throttle and adjust the high end needle until you achieve max RPM with the prop you are gonna fly on. Then back off the top RPM about 100 to 150 RPM. (More on this later.)

Go to idle and adjust your low end needle as follows:

lean and watch the tach. You want to see the engine just start to drop in RPM when you are leaning. Now richen until you see it drop off on the rich side. The position of the screw in-between the rich and lean settings is your sweet spot.

When you are adjusting the needles only turn the needles about 1/16 at a time. Gas engines are very sensitive and dont need the 1/4 turns you might do on a nitro motor.

Now when you have the engine set as above When you put your cowl back on, the High end adjustment that you backed off 100 to 150 RPM you will get back, as when you fly, the air will pass over the velocity stack inside the cowl and give you back that RPM. With the cowl on, the engine tends to want to go to the Rich side.

Now all of this is a little overwhelming I know. Bear in mind that I am assuming that your engine is set up on timing correctly.

Man I hope you get it going again and find some more RPM in that great engine. The Evolution series is awesome. By the way a little off subject but I think Evolution has a copy cat. Can you say OS-gt55?

Good luck. Keep us informed.

Glenn