66' johnson more problems

[Gonefishin95]

this is gonna be my last post for awhile, im sick of 2 strokes and ill stick to stroking 4.0's

first off a little history as to what ive done on the johnson seahorse, 1966 20 horse.
~new coils
~points
~condensers
~rebuilt the carb (i guess you can say ive done this about 4 different times if you include the amount if taken it apart and cleaned it)
~new water pump, complete unit not just impeller
~new plugs
~compression checks out to be almost exact for each cylinder.. (119/117)
~new 50:1 fuel

no matter what i do it always seems to run like garbage, ive tried it in a bucket and out on the water. WHEN i can get it to actually idle for an extended period of time (over a minute) i need to constantly adjust the Low speed needle, but it still spits and what not and tries quitting. I also almost always need to use starter fluid to get it going.

two issues i know might be a problem...first, the top plug when taken it after the running is wicked charred, which is odd because its new, the bottom one is normal. the second issue is where you hook up the fuel line to the motor. the plug leaks?

sorry for the long post, any help advice would be great
thanks
steve

 

[Gonefishin95]

Re: 66' johnson more problems

nothing???

 

[Blade_Link]

Re: 66' johnson more problems

check your fuel mix that what was giving me so many probs with my '52 seahorse, i had to ajsut it untill it ran great at idle then put it in gear and thottle it up and ajust your highspeed needle

 

[F_R]

Re: 66' johnson more problems

Well #1, you need to fix that fuel connector leak. It can't suck gas from the tank if it is sucking air from the leak.

But that probably isn't the problem.

You have to rule out a spark problem. The plugs indicate that possibility. Does it jump a 1/4" spark gap?

I don't remember which cylinder the fuel pump is mounted on in the 1966 ones. Remove it and squeeze the primer bulb. If gas squirts out the backside, the pump is bad and flooding it's respective cylinder.

Two-strokes have compression just like 4-strokes. But they also have compression / suction in the crankcase. If the above all check out, a major crankcase leak is my suspicion.

 

[crxess]

Re: 66' johnson more problems

2 Stroke or 4, if the problem is not identified and corrected it isn't going to perform.

I didn't see anything about you testing the fuel pump and you need to fix the leak.

Stop using starter fluid. it will cause the engine bearings to dry and seize. Use a spray bottle with fuel/oil mix.

Have you tried squeezing the primer bulb when it starts to stall instead of adjusting the mix? if it is loosing pressure it will change idle and eventually stall.

Many years ago a friend told me - {Replacing the blown fuse didn't fix the problem. Something caused it to blow}

Same thing applies here. You have worked well on the effected areas. Now you just need to find the culprit causing the problem.

Good luck!

 

[Gonefishin95]

Re: 66' johnson more problems

Well #1, you need to fix that fuel connector leak. It can't suck gas from the tank if it is sucking air from the leak.

But that probably isn't the problem.

You have to rule out a spark problem. The plugs indicate that possibility. Does it jump a 1/4" spark gap?

I don't remember which cylinder the fuel pump is mounted on in the 1966 ones. Remove it and squeeze the primer bulb. If gas squirts out the backside, the pump is bad and flooding it's respective cylinder.

Two-strokes have compression just like 4-strokes. But they also have compression / suction in the crankcase. If the above all check out, a major crankcase leak is my suspicion.

alright so i took off the fuel pump, which is mounted on the bottom cylinder. it appears to be in good shape. but i squeezed the bulb twice, heard gas going to carb, and on the 3rd time fuel came frm the hole that goes into the bottom cyl? is this the problem you were talking about.

o yea plugs jump a 1/4 inch gap and they are new

 

[crxess]

Re: 66' johnson more problems

Are you saying Fuel came out of the hole in the engine block or the fuel pump?

If engine - Float valve is not seating under pressure or float is out of adjustment(To low when viewed upside down) and not closing valve.
If hole in pump - Diaphram has a hole in it.

When rebuilding Carb - did you remove soft plug and use a wire to clean out the tiny holes to the carb throat?

 

[Gonefishin95]

Re: 66' johnson more problems

it came from the pump. Is there any way to temporarily fix the diaphram just to see if that is the stink? dont really wanna spend money at this point

 

[crxess]

Re: 66' johnson more problems

No real way to patch it, but you can carefully take it apart and have a look at everything. use caution not to get anything flipped or turned or it will not work on re-assembly.

Even a week pump will have the same problem as it cannot keep up with fuel burn. the carb eventually runs dry and it stalls.

While running, when the symptoms show, pumping the bulb will normally clear it up for a few minutes. That it a fast simple test to confirm pump condition.

 

[Gonefishin95]

Re: 66' johnson more problems

i took it apart, and there was no hole in diaphram, i re-assembled it and it seems to be working, i dont beleive the gas was ever comming from the hole in the back, but a loose screw...

here are some unexplained issues:
~it seems to flood itself, and there is always lots of gas in the bottom of the carb.
~the top spark plug is new, but is always wicked charred even after short run times (charred as in carbon buildup)
~the engine will run if 50:1 is sprayed into the intake, but its very hard to get going just by cranking.

 

[Gonefishin95]

Re: 66' johnson more problems

it turns over everytime now ( i forgot about this process called chking/ unchoking) , and im not saying the fuel pump is good, but i think its still my low speed needle. i know how to tune the needle, but my question is what do i do with the nut/screw the needle goes into? do i seat it in, do i tighten it? does that brass piece need to be tuned?

 

[Daviet]

Re: 66' johnson more problems

The nut around the low speed needle is a friction adjustment, tighten it down to hold jet in place. Not so tight that you cannot adjust jet.

 

[crxess]

Re: 66' johnson more problems

Ok, when you re-worked the carb, did you remove the soft plug and clear the tiny holes going to the carb throat? These are actually behind the low speed jet area and feed the carb at idle.

The low speed adjuster needs to be clean snug and sealed. Did you install new packing seals? Is the seal gasket in place in the carb bowl below the main jet?