• If you log in, the ads disappear in the forum and gallery. If you need help logging in or getting registered, send request to: webmaster@southernairboat.com

383 Stoker W/ Gear Reduction

canthony9

Member
I am trying to find information on how to tell what gear ratio I am running and what type of gear oil I should be running. Also never had any problems out of motor until the other day when my rpms would not go pass 3400, I am usually cruising at these rpms. Could this be rev limit problem or pitch problem?
 
If it’s a stinger they recommend amsoil severe gear 75-140. But other brands are acceptable according to them also. As far as the 3400 rpm goes, process of elimination there. Gear ratio should be stamped to a plate on your box.
 
Antarctica is the only place on earth (afaik) where propeller pitch has been reported to have changed all by itself.
(Obviously this is an unconfirmable rumor since this and other related information has been Classified by the Powers That Be)
So. . . . unless your fuel cell is much larger than mine, chances are you haven't been that far south.
Consequently, the only reasonable conclusion to be drawn is that your issue is not with propeller pitch (unless you changed it, and left that part out).

In all fairness, you should be warned up front, that all the resident Psychics that were here, all left to start some silly Hot Line.
Consequently, without ANY information on which to base a questimate of your problem, we will need to play 20,000 questions. Doing this is a very time inefficient process and requires other people to play. Normally, I would not participate in such an endeavor, but am in kind of a weird mood, so I will go first.

Are you still pushing the gas pedal down the same distance, while you are achieving these lack luster results?
 
Dude,
Grow some skin and post some pictures to start with, everyone here will help you out. But you gotta give up some information first. So far we have a 383 stroker, a gear box and a max RPM of 3,400. Fill us in.
 
canthony9 said:
Thanks for the response, I will start eliminating some things to figure the problem out. Thanks again

A lot of things you can do that no one else can since it's your boat.

Blind questions is real redundant, but to answer one:

a 2.38 gear will move a prop 14.28 minutes per degree on your timing.
a 2.68 gear will move a prop 16.08 minutes per degree on your timing.

Roll your timing to zero on the crank and rotate prop as a clock from zero to 6 degree!

If your results falls short or exceeds the minute clock of prop blades, I'd say your either running a 2.09 or a 2.88.

Ironically none of this matters since your post is real vague, unless your one of the boats dragging poly screws at hot dog recently?
 
Prototype said:
canthony9 said:
Thanks for the response, I will start eliminating some things to figure the problem out. Thanks again

A lot of things you can do that no one else can since it's your boat.

Blind questions is real redundant, but to answer one:

a 2.38 gear will move a prop 14.28 minutes per degree on your timing.
a 2.68 gear will move a prop 16.08 minutes per degree on your timing.

Roll your timing to zero on the crank and rotate prop as a clock from zero to 1 degree!

If your results falls short or exceeds the minute clock of prop blades, I'd say your either running a 2.09 or a 2.88.

Ironically none of this matters since your post is real vague, unless your one of the boats dragging poly screws at hot dog recently?
sounds like you would need some precision measuring tools to do that demonstration. I would like to see that done :salute:
 
Given that this is a common question and justifiably deserves an easy as can be answer for newbies,
I made this crude graphic to simplify determining the gear ratio for those who don't yet know how.

Find-Reduction-Ratio-660x800.png


Quite obviously, Prototype's method is an infinitely more accurate method than this crude questimation. :salute:
 
oops,
missed a divider.

for those that just want to turn a prop a quarter turn or so, Nice graphic Deano
 
Back
Top