2.0 CU engine underpowered

[paologray]

Hello all

Ive got a T25 with the CU 2.0 Aircooled motor. She is REALLY underpowered.

Things Ive done

Ive timed her up to within an inch of her life with a strobe light.
Ive stripped the carbs and put them back together.
Ive by-passed that idle control box and it doesnt make any difference.
All the air hoses for the vacuum advance are good, present and correct.
Ive noticed a small amount of black smoke under hard throttle.
If I leave her in gear going down a hill, blue smoke puffs out the exhaust after about 15 seconds and then under throttle for a few more seconds.
Throttle does open chokes fully.

Things I havent done

I have not adjusted the valves
I have not checked the plugs
Nor the compression

Ive bought a compression tester so will be able to do that next week.

Basically, my question is what do you guys think it could be, and have I missed anything important?

Thanks

Paul

[jason k]

valves (tappets)are hydraulic so unless they have benn played with you shouldnt need to alter anything.

yup first thing is to do the compression test, the fact that you have oil smoke suggests a worn ring

also how much power are you expecting from the thing??

they never were flying machines in stock guise......

[paologray]

No I know, but Ive also got a devon 2.0 CU engine and she flies in comparisson.

This one will get to 50 if Im lucky, maybe 60, going down hill, with the wind.

I can feel surges of power/lack of power all over the rev range also.

Where can I get spares IF the rings have gone?

[holy-mojo]

Can't assist you with any diagnosis I'm afraid, but I had the same opinion with my old 2.0 Aircooled - now have a 2.5L Forester XT Turbo engine installed approaching final stages of completion

[paologray]

Sounds like a nice box of frogs!