Atomic 4 strange behaviour

[fred1diver]

Hello everyone
I already asked this on the Moyer forum, but no answer, so here goes

I just got my timing and RPM’s adjusted on my old atomic 4, it used to run way too fast, and minimum speed was around 5 knots in gear.
Now, I am happy to say I can coast at just a bit over 3 knots, much easier to dock

before the adjustments, whenever I took it out of gear, the boat slowed down really fast, now she take a lot longer to slow down, I like it, but I simply don’t understand the reasoning behind this new behaviour, could it have affected the transmission? We did not touch it at all.
I will try to look at the transmission when I have time to go back to the boat, but I would like to know what to make of it and where to look beforehand.

thank you all so much

 

[kappykaplan]

Did the bottom and prop get cleaned while y'all were working on the engine?

 

[fred1diver]

Did it in the water, so no, nothing except the tuning of the engine has changed

 

[Project_Mayhem]

Maybe it's not shifting into neutral? Perhaps something got bumped when you tuned the engine?

 

[kloudie1]

Off the wall observation :
Might be a perception thing? Previously, with too much idle RPM, you went to neutral and then reverse to stop .. now you let it coastmore in neutral..?? I dunno.. NO, I am not in the rum yet today.
Floding or feathering prop now going to low drag at lower RPM?

 

[fred1diver]

Before I was coasting at around 5 knots, when I put her in neutral, I did not even do 50 feet before doing around 2 knots, now let’s say I am doing 4 knots, then shift in neutral I do over 200 ft before I start to really slow down . I usuall Had to put back in forward to be able to dock, now I don’t loose enough momentum to stop before the dock, I actually have to put her in reverse.

again, I am really confused about this

 

[Don S/V ILLusion]

Unless the universe has altered hydrodynamic friction, it sounds like an impossibility bur my suggestion is to patent whatever you did and license it to the beer can race crowd.

 

[fred1diver]

I wish I could begin to understand it before put a patent on it

I am just wondering if the lower idle speed could affect the way the reversing gear works
I know the at before when putting in forward, it sometimes slipped and not engage, so maybe that has to do with it???

 

[Don S/V ILLusion]

I wish I could begin to understand it before put a patent on it

I am just wondering if the lower idle speed could affect the way the reversing gear works
I know the at before when putting in forward, it sometimes slipped and not engage, so maybe that has to do with it???

Eureka!
what slips when engaged also slips when disengaged

 

[fred1diver]

It doesn’t slip anymore, so I am not sure how to figure this one out?
It engages more easily now, and I do feel it go to neutral, could it be that before it partially engaged reverse and that was what was slowing me down?

I am still waiting on ans

 

[jssailem]

Ron’s adjusted on my old atomic 4

What are your “RON”S”

 

[jssailem]

could it be that before it partially engaged reverse and that was what was slowing me down?

That was my first thought.

 

[fred1diver]

What are your “RON”S”

didn’t see that, you have to love autocorrect.
It was supposed to be RPM’s

 

[jssailem]

It deserves a few more open water tests before you get too excited. On a calm day take it out and run at various speeds, maybe 4 different RPM’s.
Idle
1/4 throttle
1/2 throttle
3/4 throttle.
With a fixed mark (buoy or float with an anchor) quickly reduce power to idle and take it out of gear. This should give you a better understanding of you coast (drift). From 1000RPM’s I found my boat can coast at least 40-50 yards, with steerage.
I use that knowledge to get into my slip without incident.

 

[Ralph Johnstone]

I just got my timing and RPM’s adjusted on my old atomic 4,

Can you elaborate on what you mean by adjusting the timing ?
Did you have problems with the timing and what is it set to now ?