Johnson 33

Hello everyone... I am new to this site and I have a Jon Boat.
the boat has a johnson 33 motor short shaft...
I am curious to know more about this motor...
I do not have any issues.. with it running....
GREAT idle... GREAT throttle response.
It just doesnt seem to get the boat moving...
I would like to start off with an example... if someone knows..
what speed should a 16 ft Jon Boat have with a 33 johnson?

What speed is it currently running? Checked it with a GPS yet?
Your engine is a good one, sharing many parts with engines ranging from 25 through 40hp in both the Evinrude and Johnson family.
There were several propellers available for this engine and I would think that you could use around 14" of pitch or possibly more on that boat to gain top end. See if you can get numbers off of the propeller and get a dealer to look up the pitch on it. I am currently running a vintage 35hp (1957) on a V bottom aluminum and see around 31mph with it just for reference. Am running a 13" pitch common aluminum 3-blade prop and am looking for a 14" - 15" pitch to see if there is improvement. Note to others reading this: - These engines are the old style with non through-hub propellers and performance will not be the same as your later models having the through hub gearcase and prop set-up.

I have been wanting to see what the speed is.. I have not yet..
Honestly I have just last night read about people using their
GPS to see there speed.
well I have a GARMIN NUVI
used for my truck ..... I am going to see if I can get it to work
on the boat....
here is what I have been thinking about
I want to go back to the lake. ( maybe today )
I want to get a TACH for the boat and wire it up....
I would like to see what the RPM is as well as SPEED.
I know several things...
first the underside of the boat is rough.. meaning ( BARNICALS are growing on the bottom )
LOL I know that will slow me down.. and I think the motor is adjusted wrong.....
MEANING.. there are 4 holes adjuster to move the motor ( closer to the transom or
further out of the transom )
WELL I know that mine is adjusted all the way out... what that means? I am not sure
but I will work that in to the test runs I will be performing.
any other thoughts as to what I could test or do while I am out on the lake?
( BESIDES FISHING ) lol....

Barnacles and green slime are worth up to several miles per hour of speed and will cost you in fuel as well.
Use your trim setting to your best advantage speed wise and seat of pants ability to plane the boat. In farther will plane easier and out farther will produce better speed numbers until you go too far. Your Nuvi will tell you that. A "Tiny Tach" is inexpensive and will work for your needs. That engine is still rated around 4500rpm at WOT if my memory is correct. Although that engine may live with a fuel oil ratio of 50:1 I would run a little more oil in it, your piston skirts will thank you for it! Properly tuned, you will very little smoke.

THANKS PAPPY
I am going to go tomorrow to the lake and test her out
I am curious.. to know. maybe you know maybe someone
else...
can I hook up an Automotive Tach?
or does it have to be a 2 cyl tach?

THANKS for the tip I was wondering.... what the WOT was..
I couldnt find it any were...
you stated 4500...
I dont even know what prop is on it.. I am guessing STOCK..
but that remains to be seen.. lol

You can hook up a simple timing light if you want, as long as it has a tach capability. No, chances are you cannot hook up an automotive tach unless it has provision for a secondary (plug wire) pick-up. There is nothing in the wiring harness to tap into to trigger it. Here is a link to a tachometer for you. You may find them on Ebay, who knows.......you can do your own searching. https://www.tinytach.com/tinytach/gasoline.php

You can also use a small engine tach, You can find them at most saw shops for under 40 bucks. Tiny Tachs are awesome and worth every penny, You can use it on just about everything. Most have hour meters built in. Plus you can use your tach to tune a old weed wacker after you remove the caps from the carb, Ain't nothing like trimming with a 2 stroke spinning at 16,000 rpms. :LOL2:

Thanks guys for the replies
I went to the lake yesterday..
had a GREAT time see pic ( LOL )
I did some testing as well....
I took the GPS and it worked out GREAT....I will now always have
that thing with me... were I put in at there are alot of stickups...and well
now comming back to the ramp at night will be easier than EVER...
just follow the blue line.... AWSOME. gotta love technology... lol
so so the boat does 16mph... ( NO GOOD AT ALL )
so I let the motor back down closer to the transom.. and then tested again..
no different in speed but I do like the motor kicked back up.. it rides much better.
learned at least that...
while at WOT I sprayed some Carb cleaner in the general direction of the carb
and the motor BOGGED instantly.. so the motor is getting the fuel supply it needs.
I also forced the linkage to its max to achieve max power.. NO CHANGE...so my
linkage adjustments are all good....
I did change the plugs... while out on the lake...gapped at .030 the new plugs
proved to be better... I now get a STEADY 17mph... so I noticed an improvment..
but I dont know the RPM yet.. and that bothers me...
I am a definate kinda guy.. I want to know these things.. so I am thinking about buying this product....

https://cgi.ebay.com/ebaymotors/Small-Engine-Tachometer-Tach-and-Hour-Meter-Hourmeter-_W0QQcmdZViewItemQQitemZ160468062746QQptZGoQ5fKarts

and I will see what the RPM's are... that will help me determine my NEXT STEP...
A NEW PROP... I am thinking thats what I need.. I NEW PROP with a different PITCH maybe..
I will read up and try to learn what size and pitch all mean and can do for me.
anyone wana chime in here it would be most welcome.
but I am thinking I need a NEW and ONE with something different.
well check out my catch .... I had the guys back at the boat ramp very envious
it was alot a fun.

i bet dinner was delicious

YOU SAID IT... lol
already filled the fish.. and soaking in
lemon juice and salt water....
thats my tip for you all that like to fry your
fish...
I soak them like that for one day....
then rinse.... then freeze......
when I go to fry I soak in Butter milk.
put batter in a plastic bag coat then fry...
MMMM MMMMM MMMM GOOD.... lol
Edit/Delete Message

Back to your performance issue. Love fried cats by the way..............Your speed of 16mph on a flat bottomed Jon boat is way below the capability of the engine/boat. Start by cleaning the crud off the bottom and post what improvement came from that before we start doing any checks elsewhere. You can use the barnacles for chum!

PAPPY
You hit the nail on the head.....
I have plans to go fishing SATURDAY...
so in the mean time OUR local State Fair.....
Kentucky State Fair starts tomorrow....
I bought tickets to take the Wife to see
SUGAR LAND... ( should be fun )
FRIDAY... is the day I plan on raising the boat and
cleaning...
I have a CHALLENGER AUTO LIFT... and thats how
I plan on taking the boat off the trailer...
SHOULD BE interesting...
I will post pics of the process... and I will share with
everyone....
CANT WAIT.....

Teammuir1, does your motor run pretty good at idle and good up until about half throttle? I have the exact same motor(1969 33hp) on my 16 foor jon and i think that my high speed adjustments might be out because mine is doing very similiar to yours. Have you tried to flip the door down and choke the motor a little to get some more fuel into it ? I believe these motors are supposed to be 25:1 but i run 4 ounces to the gallon which puts it at 37.5:1 and i haven't had any issues. I am also located in Ky.

I have done alot of motor testing..
I now believe that my motor is not the problem..
she is running GREAT.... I think my problem lies with the boat
in its self... ( what you ask ) lol
well the boat is HEAVY I THINK... the boat was built by my grandfather
back in 1981 now since then the boat has been garage kept...
all the time ....
when I got it I have a cover made for it and it say out side for about 4 mths.
since then its been inside... what I have discovered since I have been
using the boat here more that it has gotton slower...
I am now thinking that the boat is water logged.. the materials are just
old and rotton with age and being out on the lake water logged.
I weighed the boat the other day ..... how you ask.. well
I worked on the underside of the boat ( I painted the entire bottom of the boat )
took the trailer to a local Truck stop.. used their scales....
then after I was done the next day.. I took the boat and trailer to the same scales
and now I know what everything weighs....
I am sure my motor is fine.
I tested the motor same way you stated using my hand as a choke.. I blocked the carb
inlet.. and the motor wanted to die... I aslo further tested with carburator cleaner..
while spraying the same direction as the carb....the motor wanted to die immediately
so its not starving for fuel....
Were in Ky are ya...?????

So I have cleaned the crud... from the bottom of the boat...
here are some pics for the update....
but not yet tested on the water...
I would love to be out there right now ( hint hint )
but I have a B-day party to go to .. family comes first.....
so I might be able to test Monday or Tuesday.

Here is a picture of the amount of crud that was on the bottom to give you
all an idea as to what I was dealing with.

Just so you know i took my decked 1648 out tonight with my identical motor and it went 22 mph but i think that i still have more. Possibly another 5 mph i believe with some tuning.

GREAT info
thanks for that I am curious to know what you boat looks like
can you post some pics?

When I am going 17mph down the lake thats with my wife with me
as well..... and fishing gear.
1.) 2 marine batteries
2.) minkota trolling motor
3.) anchor
4.) 1 tank of fuel 5 gallons metal tank
5.) 1 big cooler full of 22 pds of ICE
6.) Lighted Jugs ( 12 of them )
7.) organizer tub ( all dry items )
8.) 4 fishing rods
9.) 1 small cooler of drinks only
10.) Riding Lawn Mower battery ( spot light )

I dont think I can think of anything else we have on the boat......
now mind you all this stuff... is added to the weight that the boat
already weighs in at.....
so she Is a floating TANK lol
11.) small cooler for all the BAIT ( strawberry chicken, strawberry shrimp, Nightcrawlers )

If your boat is indeed that heavy then you should start thinking about finding a prop with less pitch to keep the engine up in the RPM band for longevity. Looks like you took an amazing amount of "bait" off the bottom of the boat so you should see a difference.

This morning was the first time I was able to take the boat
out since I cleaned and painted the hull and sides....
well I was not expecting this ...
I was able to do 20mph steady.... that is a 3 mph increase
Not bad for just some maintenance..... lol

So we went fishing again..
and caught 2 ,,,, 9pd r's ..... Very nice

so I am working on a deal for a bigger motor.....
I am real egar to get started on my full interior gut. and remodel.

there was a guy out fishing in the area we were in so I trolled over
and we started talking... well after observing his boat I realized that
he has those floatation boxes on the transom of the boat...
He stated he really liked them and that they really helped
keeping the boat up while he has a 150 Merc on the tail.
I really liked the looks of his....they were stair stepped...so
you could actually use them to get in the boat from being in the
water.... dual function.... that will be a MUST for me....
any one else have these on their boat?