115 johnson v4... problems

[dungY]

i'm having some problems on my johnsons v4
it's a 1980
i mix my gas 100:1
at inital startup it sneezes and sometimes dies out because of that, but when it warms up it seems to run fine.
When on water it takes a while to plane
and the fastest i can get it to go is 27-30 mph is this avg speed for a 115 v4 outboard on a 17 ft fiberglass bass boat?
when i stop to fish i noticed ?gas/oil? on the water in the back by the exhaust
is this unburned fuel? or is that normal on an older motor
It makes me think for some reason that i am only running on 3 cylinders.....
how should i attack this...
I do need to decarb and spark plugs were new when i began to restore the motor

any help would be appreciated

sorry for the long post, i am trying to provide as much information as i can as far as symptoms and what i have done to it. I am new to boating and do all the work myself because im a student and don't have a big budget

thanks in advance

 

[Cricket Too]

Re: 115 johnson v4... problems

Well right off the bat, you need to STOP running at 100:1, especially if you just rebuilt this thing. If it's a new rebuild run it at 25:1, that's double the oil, 100:1 is half the oil it should have.

Because of that, I'd say you need to check your compression first and see if any damage has been done.

Your sneezing problem at idle indicates a lean fuel/air mixture, which could have also caused some damage at higher RPM. The lean issue, could also be why it takes a while to plane. That engine should be planing out a 17ft boat in no time, if it's set up properly.

Compression test is needed...first thing.

 

[dungY]

Re: 115 johnson v4... problems

i'm sorry i mix my gas at 50:1 not 100:1, but anyhow i should still bump it up to 25:1?

 

[Cricket Too]

Re: 115 johnson v4... problems

OK, well that's one scary problem down.

When you say "re-store", do you mean you just re-built this engine or you are just getting it back going after it's been sitting a while?

Either way, have you rebuilt the carbs?

 

[tashasdaddy]

Re: 115 johnson v4... problems

if it's a new rebuild yes, for atleast several tanks. the oil slick is some what normal. suggest a compression check, post results. check spark with a $10 spark tester at the auto parts store. whats you wide open throttle rpms. if you don't have a tach, you can use a induction timing light with the tach function. you can also use the timing light to make sure you are firing on all cylinders at speed. my moving the pick up from spark plug wire to the other. as far as 27 to 30 mph, it's slow unless the motor is not performing, or the boat is vert heavy or water logged. i expect 38 to 45mph.

 

[dungY]

Re: 115 johnson v4... problems

i do not have a tach or a compression tester, i will be purchasing that tonight when i get off work

The boat sat for approx. 3-4 yrs before i touched it,
I didn't do a rebuild on the motor, i basically wanted to make sure the motor ran before i put much money into the boat
The first thing i did as far as restoring was
-empty the gas tank, cleaned it and put new fuel in with 50:1 mix
-check fuel lines and replaced "primer/choke cap?" with a new one which had a built in schrader valve
-bought new plugs and replaced old ones
-cleaned carb with carb cleaner..... i may need to go back and do a better job at cleaning the carb

I have yet to run seafoam which many have suggested

 

[reeldutch]

Re: 115 johnson v4... problems

before you do anything and sinking more money in it do as cricket suggested and check the compression.
if thats even within 15% of each other go ahead and rebuild the carbs.
clean all the jets and orifices, im shure it will need it done.
than check out the fuel system for old hard hoses, dirty filters, dirty tank etc etc.
fuel restriction will lead to lean sneezes.

check the lu for milky oil and metal shavings.
drop it and install new waterpump and tstats.
buy a timing light set tdc pointer and set the timing.
do a sync and link and probbebly your problems should have been eliminated or corrected.

if it still sneezes after this tune up, you might have a leak somewhere.

good luck

 

[Chinewalker]

Re: 115 johnson v4... problems

FYI - the only way you can properly clean a carb requires a complete disassembly. Simply spraying carb cleaner on and around it does nothing. It's gotta come apart, and seeing as how the boat has sat for several years, it's more than likely you have gummed up carbs...
- Scott

 

[chazamerica58]

Re: 115 johnson v4... problems

wouldn't hurt to put a new water pump in. i just bought a brand new one on ebay complete water pump unit w/ housing for $9.00. easy to replace!!!!

 

[dungY]

Re: 115 johnson v4... problems

I checked the compression this morning,
It read +/- a 1 or 2 from reading error
facing forward from the rear

112 107 <---- i noticed this plug was a tad cleaner
than the other three but still oily
112 110

-As far as the lower unit goes, i drained the old oil and put fresh oil in

 

[Walker]

Re: 115 johnson v4... problems

Do the carbs. See Chinewalker's post

 

[dungY]

Re: 115 johnson v4... problems

will do, i'll be working on the carbs sometime tonight.

I was looking at my plugs and was wondering why just that 1 plug was considerably cleaner than the others....

and on a side note
what should the gap be on the plugs?
i did not gap my plugs when i first bought them

 

[reeldutch]

Re: 115 johnson v4... problems

if its concidderably cleaner it could be water intrusion leaking headgasket.
but 107 psi is still not bad.

keep a eye on that cylinder.
put a dirty plug in and see how it comes.

yes go take the carbs off and clean them out spik and span.


good luck

 

[Walker]

Re: 115 johnson v4... problems

The plugs you need are Champion QL77JC4 and gapped .032-.040, but gap them all the same. I feel the V4 Crossflows run better with .032 gap. A lot of other people like to run them at .040 gap.
I think if you get the carbs cleaned real good that considerably cleaner plug will start looking like the rest of them.

 

[dungY]

Re: 115 johnson v4... problems

I just dissassembled the carbs and got them all cleaned up and reinstalledi have yet to start the motor and rediagnose. I will post my findings when i do


There is a spring with a hook on the end that pulls the throttle forward when you accelerate
Can anyone give me the name of that part?
i noticed that when i put the selector in full throttle the spring no longer applies enough force to pull the throttle(on the motor) all the way forward.... I was gonna call a boat shop for the part but i don't think
"i need a spring with a hook on the end" is sufficient
= )

thanks

 

[dungY]

Re: 115 johnson v4... problems

I think i found the problem and to better explain what i am facing i attached a photo.
I checked my spark plugs and am not receiving spark to one of my plugs. The plug itself is brand new Now i am not receiving spark to the pack at the top.
but i am to the bottom. i did this by pulling the plug and putting a testlight to it.
now the problem i face is tracing that wire backwards to the source, ...... easier said than done...
Now this is where i am lost

i am not sure what the "red circle" wires and the "green circle wires" are, I am not able to trace it to the "blue circle wire" because it goes into the blue box marked A and that does not come apart....

I don't if i helped or made it more confusing.....
PLEASE HELP!!! d

 

[Walker]

Re: 115 johnson v4... problems

You need a manual for proper testing procedures of the ignition components.

 

[ccnstlr]

Re: 115 johnson v4... problems

The red circle is the leads from the charge coil from the stator. The green circle is the leads from the timer base. The blue box is the power pack (Capacitor Discharge Unit).

The capacitor in the 'pack' is charged by the charge coil. Then the timer base sensor coils send a trigger to the pack causing it to discharge itself through the orange wire 'little blue circle' to the ignition coil which fires the plug.

So any one of these could be causing you a problem. Also check the ground connection at the coil. And check for connector deterioration at all of the harness connections as corrosion seems to find its way there.

As Walker says, you need a manual to perform all the tests to determine where your problem lies.

 

[ccnstlr]

Re: 115 johnson v4... problems

I'm no experienced boat mechanic, but I'm thinking that if you say the lower coil on this bank is receiving power that the charge coil is in fact charging the pack. That leaves the power pack, sensor coil(timer base), ignition coil, or wiring/connector issues.

 

[OBJ]

Re: 115 johnson v4... problems

From what I can see in the pics, just may very well be the ignition coil. They look very old. Do any of the coils have cracks in them?

You can swap the leads from the coils to the power pack and see if the problem changes to the other hole. If it does, then you will know the coil is bad.