Timing on a M20F rajay

[Evan Amaya]

This is my first Mooney and it has been in the shop getting an intensive annual after prebuy.  It is a 1968 turbo normalized rajay.  My question is this.  Is the timing the same as a stock F?  The engine data plate has a 20 scratched over the 25 degrees.  The flywheel has two XX stamped over the 20 degree mark.

thanks.

[kpaul]

13 minutes ago, Evan Amaya said:

This is my first Mooney

I cant help you on your question, however welcome to the site and I really like the polished Mooney, looks great.

@M20Docis one of the best resources on the site when it come to most things maintenance related.

[Guest]

The STC documents for the turbo conversion should have some information on the correct magneto timing.  Failing that, there is a service instruction from Lycoming which details the change in timing from 25 to 20 degrees.  

Clarence

[FoxMike]

I am pretty sure the timing should be 20BTDC.  I owned a RayJay many years ago and I am sure I never changed the timing when I installed it.  Maybe something changed in the last decade or so but I doubt it.

[jetdriven]

If you didn’t change the timing when you installed the Rayjay then it should or can be set to 25 degrees.  The 20 degrees timing was optional. It’s useful if there is no other way to keep your CHTs in line but it costs you forever in speed and fuel. 

[Shadrach]

11 hours ago, FoxMike said:

I am pretty sure the timing should be 20BTDC.  I owned a RayJay many years ago and I am sure I never changed the timing when I installed it.  Maybe something changed in the last decade or so but I doubt it.

Someone must have changed it if you had an M20F.  I don;t think any of the A1A engines left the factory with 20° BTDC, timing.  If all RayJay TN'd Fs are timed to 20° BTDC, that explains a lot of the confusion I've had with regard to their performance.  

[Evan Amaya]

Thanks for the input.  My A&P read all the rajay manuals I have and the timing was not changed from factory setting for the stc.  He also told me that SI-1325a had been recended and the timing should be 25 btdc.  The F is going to the avionics shop for a month or so for all new fun stuff then I can fly.

[Shadrach]

2 hours ago, Evan Amaya said:

Thanks for the input.  My A&P read all the rajay manuals I have and the timing was not changed from factory setting for the stc.  He also told me that SI-1325a had been recended and the timing should be 25 btdc.  The F is going to the avionics shop for a month or so for all new fun stuff then I can fly.

You’re in for a treat provided you have no cooling issues. You’ll be amazed at the difference 5 degrees of advance makes in take off and climb.

[Brian Scranton]

My A1A Ray Jay is 25 degrees.