Topic: 1958 Johnson 5.5hp carb/starting problem *FIXED*

This topic has 26 replies, 10 voices, and was last updated 5 years, 6 months ago by retiredoz.

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September 30, 2018 at 3:07 am #11391
Eric McNett
Participant
Had a chance to put the carb kit in the 58 CD-15 today. Still over gassing and wont run, checked points and theyre good. Float is slightly above even compared to gasket surface when upside down, needle moves freely with float. Set bottom needle 3/4 turns out and top needle 1 1/4 turns out. Plugs arent fouled and are correct. Throttle cam and roller are synced. Im a bit lost as to what my problem is? Last owner replaced coils but dont know about points/condensers. Seems like it tries sometimes other times its like theres nothing trying to go boom in there?

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Eric McNett
Seattle AOMCI Member
September 30, 2018 at 3:22 am #83723
outbdnut2
Participant
US Member
Have you checked for spark? You said coils were replaced, so that’s OK. Condensors could be bad, but rare to have them both bad. Take out the spark plugs and put the wires back on them. Position the spark plugs so the metal base touches the engine block or head – don’t worry about paint, the voltage will jump through it. Pull the starter and look for spark in the sparkplug gaps. This test works 90% of the time for me, but spark may still be weak. To get a for sure test, you need to take an old spark plug and bend the gap out to about 1/4 inch and see if the spark jumps that. Under compression, a spark just jumping the .030 gap outside the cylinder may not be enough, When you rebuilt the carb, did you get the thick donut washer/gasket on the bottom of the jet that extends through the center of the float and mates with the bottom of the carb bowl? If you missed this (a common thing for people to do) it will flood, but it may start and idle, but will flood and kill as the throttle is advanced.
Dave
September 30, 2018 at 12:24 pm #83731
frankr
Participant
US Member
Did you ask about this carb somewhere before? Gas pouring out when you press the primer button? If you are that guy, it was suggested to check the bowl vent. Have you?

EDIT: That was "drifter". See his thread titled "frustrating morning"
September 30, 2018 at 5:10 pm #83753
Mumbles
Participant
The 3/4 setting on the high speed needle is a rough setting and just meant to get the motor started. Once it’s running, try speeding it up a bit and slowly turning the needle clockwise to lean it out. It should make a difference.
September 30, 2018 at 7:57 pm #83757
lloyd
Participant
US Member
Are you sure this motor has high enough compression to run at all?
October 1, 2018 at 2:19 am #83782
Eric McNett
Participant
the gauge i have is a shotty harbor freight one, the last two motors i have its read about 40 lbs on both motors, im going to try and source a good one to check this motor but pulling it over it feels strong. and it tries to run i just think that with the fuel pouring out its trying to run way to rich. I may pull the fly wheel and the armature plate to make sure all the connections are tight at the coils and the points clean.

Eric McNett
Seattle AOMCI Member
October 1, 2018 at 7:00 pm #83834
Eric McNett
Participant
ok, got out in the garage today and disassembled the carb. Checked the vent openings and appeared to be clear, started up the air compressor and let it build up then shot some air best i could through the vents, and got left over gas sprayed out of both holes and adjusted the float to be level with the carb body. Then pulled out the only spark tester i have a Thexton 404, screwed the needle out to 1/4" and checked both coils. For one pull on the upper plug i got a bright blue lightning bolt then nothing( consistent with it trying then sounding like nothing was happening) then tried the lower plug and got nothing at all out of that one pulled 5 times on each plug and only got the one strong bolt. Coils are new CDI units but unsure when exactly they were replaced, points are good and clean and adjusted to .020" unknown if they and the condensers were replaced along with the coils.

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Eric McNett
Seattle AOMCI Member
October 1, 2018 at 9:02 pm #83838
Eric McNett
Participant
so i revisited this just now, either im not getting a good ground or my spark tester doesnt work(doubtful). hooked the tester up again in multiple spots and no spark, but when i hook the leads up to the spark plugs it tries to fire. And with that gas still pours out of the carb and it looks like its coming from the main jet(pic attached). After a few pulls i let it sit and i took a video, it sounds like its sucking air, but i cant tell whether its the piston still trying to suck air or if its coming from the vents(and didnt think to stick my finger over either of them or both), will try and post that short video if i can. I will also try and post the video i took of a couple pulls to show what its doing.

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Eric McNett
Seattle AOMCI Member
October 1, 2018 at 11:30 pm #83844
fleetwin
Participant
US Member - 2 Years
OK, well I think you may have a few issues going on here….
I thought you cleaned that carb, looks pretty cruddy…
Admittedly I am getting confused also…
It was my understanding that you put on a different carb body on this engine and the flooding issue was resolved…
If not, is that an OMC/OEM carb kit? I’m just asking because that bowl gasket looks kind of mess up/distorted, perhaps it is hitting the float inside the bowl preventing it from seating the inlet needle properly…
Let’s get some accurate compression readings also…
I’m guessing the ignition system needs to be gone through thoroughly also, perhaps the wires should be replace as well…
But, before we get started on all this, have you drained/refilled the gearcase? Is the gear lube OK/no water? Have you replaced the water pump impeller? Forgive me in advance if you have addressed these issues in previous posts….
October 2, 2018 at 12:30 am #83848
Eric McNett
Participant
1. Carb kit installed, not from BRP but ive used this kit before without issue.
2. Carb was completely disassembled, blown out with compressed air along with the top plug removed and blown out. bowl and inside of carb were clean and free of debris when i got it but decided to put a kit in it since it was leaking and I suspected the float may be bad.
3.That was another poster with a similar issue.
4.I dont have compression readings as my POS gauge will give me the same 35-40PSI readings its given me on two other engines that run just fine, ill have to find another one. *****EDIT***** stuck the gauge i have on it (US GENERAL) and it shows me a little over 30psi, but im not trusting that at all.
5.I have not done anything to the gear case, oil or the waterpump as i wanted to make sure it ran before i went that deep into it.

Eric McNett
Seattle AOMCI Member
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