Just another overhaul thread

[Surcouf]

This is status of tuning situation... very rough

https://youtu.be/YibRPR9ARRg

[jcwright]

Hello Surcouf.

I recall 3 gauges in one of your earlier photos, but I don't think I saw a tachometer. Do you know what rpm you are idling at?

jack.

[Surcouf]

Hello Surcouf.

I recall 3 gauges in one of your earlier photos, but I don't think I saw a tachometer. Do you know what rpm you are idling at?

jack.

no I do not, the middle one (not connected in voltage). I would have used a gun from the office, but with Covid situation, I have not been able to get it. At this point, this engine is not even idling yet. I am "holding it" playing with choke and gas levers for now.

[jcwright]

It's hard for me to judge RPM from sound alone, but if I had to guess I would say your idle RPM are low. Below is a link to my A4 right after its rebuild. It was idling at about 750 according to my tach gun. MM's recommended idle is in the 600-1000 range.

https://www.youtube.com/watch?v=RKvHFCEKO-w

jack.

[Ando]

This is status of tuning situation... very rough

https://youtu.be/YibRPR9ARRg

That sound is music to my ears. Not too rough imo.

[edwardc]

I agree with the others. The idle RPMs sound too low. Try increasing the setting of the idle stop screw on the throttle lever.

Although others have reported idle as low as 600 RPM, mine sits at about 850-900.

If you check the carb, be absolute sure that all the idle passages are clear. Simply spraying carb cleaner through them won't cut it. You must physically "ream" each one with a small wire. The center wire from a bread tie is just the right size and stiffness for this job. In addition to the idle jet, there are three small openings in the throat that straddle the throttle plate when closed.

[thatch]

PCV?

One element that has a direct affect on the idle capabilities of an A4 is whether or not it has a PCV system. If a relatively healthy A4 has a clean carb and has been set to factory ignition specs, I have found that they will idle as low as 500 rpm's without stalling when going in and out of gear. A4s with PCV valves normally seem to want to idle in the 700 or higher range.
Tom

[Surcouf]

Tchatch, no PCV system here (just the usual bent plastic tube coming in front of the flame arrest or at the suction of the carburetor

One question for you guys: I found that at the bottom of my Moyer Marine parts box, and I am not sure if that comes from MM, or is just another lost item from my general mess.... any idea what this is??

[Surcouf]

- It: «*hey you*!!!*»
- me: «*who is talking?*»
- it*: «*it is me of course, Bomby your engine!!
- me: «*OK it is so late I am starting to hear voices...*»
- it: «*stop being stupid... what are you doing wrenching me at 1AM? «*
- me:*«*you not running well, not idling. So I am trying to troubleshoot and cure you*»
- it: «*and what have you done?*»
- me: «*compression, Check. Sparks, check; timing, check. Fuel, just overhauled the carburetor, check. Exhaust not clogged, check. Timing, check. What is left???*»
- it: «*I would like to sleep too, so the best is to help you... what is written on my side? «*
- me: «*?????*»
- it: «* what is written on my side? In the casting!!!*»
- me: «*your date of birth? We are both from the same year you know*»
-it:*«*no idiot, above that!!!*»
- me: «* firing order 1-2-****!!!!-4-3...***** ****!!! I can’t have done that mistake «*...
And yes ...
- it:*«*and suddenly he gets it... not the brightest bulb of the block this owner!!*»

And now it purrs like a kitten!!!

[thatch]

Firing order quiz

If you don't already know why the firing order is 1243, do a little research on the "flat crankshaft" and impress your friends on the dock. Almost everyone has made the firing order mistake at least once.
Tom

[Administrator]

To paraphrase a comment often used by my favorite "news aggregator," If you want to publish a comment from all the guys who have done that, you're gonna' need a bigger blog.

Bill

[ronstory]

... regardless how we got here, this is still a "WOO-HOO!" moment.

Congrats!! May Bomby purr for many years.

[Ando]

... regardless how we got here, this is still a "WOO-HOO!" moment.

Congrats!! May Bomby purr for many years.

+1 WOO-HOO!!!

[Surcouf]

Sorry I have to vent here... who is the absolutely stupid electrical engineer who designed the Catalina 27 electrical circuit and decided to implement a 12 feet harness with trailer-type plugs? What was the goal? Move the engine to the dock to test bench it???
2 broken pins on my harness clogged with corrosion... time to re-wire all that!!

3 of those 8 connectors were unused following decades of modifications.

The only positive aspect of that harness is that I do not need to buy any cable to re-wire properly all that!!!

[ndutton]

We have always - - admittedly incorrectly - - assigned the responsibility for those plugs to Catalina but the cold, hard fact is they are an original Universal/Westerbeke monstrosity. Here is a drawing from the Universal/Westerbeke Installation and Maintenance Manual, page 18, that clearly shows the 8 pin plugs at the engine and instrument panel with the extension harness connecting the two together.

The corrective action is to get rid of the plugs by either butt splicing the wires together, adding screw down terminal strips in place of the plugs or creating an entirely new harness of your own minimizing terminations. As for the latter, it's the most work but in my opinion produces the best result especially considering your engine wiring is at least 40 years old. Here is what can be achieved. Yes, that is the same engine in the same boat.