Carb sync issue

How old is the engine and have the carbs ever been overhauled? I use gauges because you can diagnose with them and see other issues that a Carb Mate can't. 

Its 10 years, 730 hours. Cant find any papers describing overhaul or something like it.

we bought it last autumn.

Could an old diaphragm cause this?

sometimes I see green light all the way up, but it Splits on the way down.

yeah, I will look for a double manifold gauge in our hangar. CarbMate can only do so much

Hi Tage,

If I purchased a Rotax powered aircraft with a inadequate maintenance record - 

As a minimum,  I would do the full  5 year "rubber" replacement (including carburettor rubbers) along with a 200 hr  standard service, propeller pitch & balance check.😈

Offcourse Sean you Are completely right. Actually we have done a complete 600hrs on the aircraft, changing all bolts in Wings and landing gears, new Control cables, tires and brakes. The engine has completed a 200hrs inspection, compression check, new sparkplugs etc. We Are awaiting the original wooden propeller back from painting, and we will do a dynamic balancing procedure.

I am previously a lycoming/continental guy, A&P here in Norway, but I must admit the Carburetors caught me offguard. I checked the rubber mounts visually- they look not that old, and somehow the diapgraghms was forgotten. All hoses Are already new ones.

I will order two diapraghms, but it the meantime its good to have these discussions about what the problem Could be.

thanks again 👍🏻✈️

If the carbs are ten years old I'd just get them overhauled and remove any interior and functional issues with them. At ten years old the "O" rings will be dried and cracked and the needle valve tip my be hardened too. The idle jet is probably clogged too. I'd replace those rubber carb sockets as well.