Hi Guys
I have been having an ongoing problem with rich mixture in my Lycoming O290d2, after trying various fixes my engineer has discovered that an MA4SPA has been fitted instead of of an MA3SPA, my question is can my existing carb be re-jetted to produce less fuel or is it a case of replacement?
Thanks in advance
T18

Well yes but it’s Saturday and a they are closed, I’m looking for a heads up from someone like Cockney Steve.

T18

Your problem as I see it is it does not comply with the current type data certificate, which the engine is approved under, see link, I would try phoning the likes of Nicolson McLaren and have a chat, they may be able to do an exchange etc, incidentally they also tend to fit a different manufacturers carb these days that gets rid of several inspections like the float bowl coming loose etc. Have you contacted whoever overhauled it as I am assuming they were responsible for the mix up.

http://rgl.faa.gov/Regulatory_and_Gu...FILE/E-229.pdf

https://msacarbs.com/technical-data/engine-eligibility/

Hi Nutloose

It’s an LAA type and certainly the wrong carb fitted, Nicholson McLaren overhauled the carb around 50 hours ago, the engine has recently had a top end overhaul and the rich mix has become more pronounced.
I’m surprised that it hasn’t been spotted before.
The a/c was built in 1970 as the demonstrator for the parts manufacturer “Thorp”
Thank you for the advice I will call N/M tomorrow, I note that Airpart may be an option although I won’t be exchanging like for like. The MA4 is for an O320 so may be more desirable.
Regards
T18

Thanks Nae
It’s not possible to reject, replacement on order.
T18

That should have been re-jet....
would it be possible to replace the cylinders with O320 ones?
I’m in conversation with Nicholson McLaren at the moment, it’s certainly more involved-complicated than I f

Hi Nae

Thanks again for the heads-up, that was very useful, it seems I may be able to have the original studs removed and new ones fitted so all I need now is a carb.

T18