Still working on idle 454 Merc with video of tach

[anderso8623]

I got the motors running better. One seems near perfect the other is questionable. I have two videos, one is of the intermittent “jump” in rpm. It is barley noticeable and is on the starboard tach. The second is of the engines starting; the starboard engine is like a trampoline and the port goes straight to proper RPM.

My my question is two fold, is the intermittent jump a concern? And is the odd start a concern.

Semi unrelated, I have an old school synchro light on my dash. Through the viewfinder, it resembles an orange cone that is split in half. How do it use this instrument? It seems that at cruising speed, I can get the two halves to pulse it sync. At idle, I can’t even get close.

https://youtu.be/dZm803K2S8s


https://youtu.be/TpqVslVbBwo

 

[Bondo]

I got the motors running better.

Ayuh,..... Unfortunately, most of Us can't remember all of the details of everybody's motors,.....

So what are Yer's,..?? other than 454s which have been around for decades, in many different configurations,.......

 

[anderso8623]

Sorry, sometimes I just start typing as to not forget what I want to say and for get theses details!

They are 1979 inboard, direct drive, Merc 454. The have Rochester Quadrajets that have been rebuilt and I just tuned them. RPMs in the video should be accurate or close based on previous advice.