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1992 Johnson 150 wont start

K

kegger

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Motor cranks but will not start and idle. Will sometimes start at 1/2 throttle but runs rough and fuel dumping from prop exhaust . Flames .noticed a slight drop in compression on 2cylinders (2 or 3points)90-102 worst to best . Water got into fuel tank. Still won't run on aux tank replaced needle valves and seats.floats All set good. Running out of ideas, please help! Mikep
 
I think the stator maybe ok output peak out of speck (not much) also vacume switch on front fuel plate suspected cause?
 
ur carbie isn't tuned properly. too much fuel and maybe without looking at motor u got ur spark leads hooked up wrong. check ur spark plug gap or even are they the right plugs. to me I reckon ur idle mixture screw is all wrong hence fuel out the exhaust and flames equals running too rich too much fuel not enough air. for best combustion u need a air to fuel ratio of 14 parts air to 1 part fuel.
 
is the primer lever turned the correct way or has correct operation been checked? Check the spark plug wires make sure they are on the correct cylinders. What is your model #? Has anyone ever taken the flywheel off of your motor. IF that is a Looper motor i believe the flywheel is bolted on no key way on it.
 
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flyingscott said:
is the primer lever turned the correct way or has correct operation been checked? Check the spark plug wires make sure they are on the correct cylinders. What is your model #? Has anyone ever taken the flywheel off of your motor. IF that is a Looper motor i believe the flywheel is bolted on no key way on it.
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Thanks so much for the replies guys. I appreciate the help. I will check fuel primer operation first. red lever is down. model J150ELANC wires good on plugs
QL77JC4 .030 gap. I never had the flywheel off in the last 11 years I have owned this, nor messed with fuel mixture screws but have rebuilt carbs 3 times the last time a few weeks back. floats set right in 6 carbs and top fuel reservoir. all needle valves and seats replaced. no leaks after assembly. primer bulb hard. reeds appeared ok as much as I saw of them. this is a looper. was thinking fuel not being burned or vaccume switch problem or optical sensor
 
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The red lever should be " inline " with the primer valve body.---Tested the stator ohm values ?----Tested battery and starter motor ?------Looked for issues with crankcase compression ?------Post the actual cylinder compression numbers.
 
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racerone said:
The red lever should be " inline " with the primer valve body.---Tested the stator ohm values ?----Tested battery and starter motor ?------Looked for issues with crankcase compression ?------Post the actual cylinder compression numbers.
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compression:

P S
recent 90 103
90 100
88 98

2009 97 105
93 102
90 98


motor ran 5400 RPM@full throttle, june 2017 5100RPM full throttle. motor is old.
red primer lever down,inline and disconnected last time tried to start
reluctant to spend money on old technology. checked stator voltage outputs with
ES DVA adapter and found output at 1/2 values to ignition components at cranking
with a full battery. probably needs rebuild.
 
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Kegger's Son said:
We have tried the open all spark tester all 6 @ 7/16th gap. No spark whatsoever. Turn the tester to 4/16ths and we have sporadic spark on all cylinders.
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With regards to the starter output. Let me give a clearer picture. We are using DVOM and purchased a DVA adapter for it to check the outputs of the electrical system for this powerhead. The DVA adapter we are using may or may not be with the particular DVOM that we are using to test with. That being said.

We know that to test the stator you should test at the harness plugged into the powepack that has 6 wires. 2 orange - QUICKSTART and 4 Browns - STATOR outputs too the powerpack. Can anyone on this thread give insight into what brown wires should be tested with each other, and what should those voltages be while cranking?

Just to add...we have swapped the powerpack with a known good one already so that has no relevance in this issue.
 
racerone said:
The vacuum switch sounds the alarm if there is a restriction between the fuel pump and the tank pick-up screen.
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Racerone, thank you. Thats what i suspected.

However i have additional questions. If that vacumm switch is faulfy, could it cause excess fuel to flow through the carbs?

Additionally, that switch actually has fuel flowing through it ti measure the fuel pressure? Or just vacumm?

Thanks in advance!
 
Fuel does NOT flow through that switch !-----That switch can NOT cause excess fuel flow to the carburetors either !!-------That switch triggers the ALARM when there is a flow restriction to the motor !
 
racerone said:
Fuel does NOT flow through that switch !-----That switch can NOT cause excess fuel flow to the carburetors either !!-------That switch triggers the ALARM when there is a flow restriction to the motor !
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@ racerone, thank.you for your quick reaponse and knowlege. I have fuel shooting out of that switch while cranking and running at the preaent moment. Sounds lime i have a routing issue with tubing in regards to that switch.

That being said, if i eliminate that switch completly could i in theory still start and run the motor correcty. Or would i have to short the wires of that switch?

To add more too that we had a different switch on this motor before this all started. We got another one from a local dealer that gave this bad one to us for free. Now we know why its free. However, is the tub coming off the outside of that switch supposed to go to the primer fuel pump?
Thanks much!!
 
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You are confusing me now.----Are you talking about the electric primer valve here, or the vacuum / restriction switch ??----Post pictures of these items so we can compare oranges to oranges here.----Do you have a manual of any kind or just guessing here ?
 
racerone said:
You are confusing me now.----Are you talking about the electric primer valve here, or the vacuum / restriction switch ??----Post pictures of these items so we can compare oranges to oranges here.----Do you have a manual of any kind or just guessing here ?
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Racerone - no pictures necessary. Sorry for the confusion. We are talking about the vacuum switch. We do have a manual but juat crappy Chilton. Usually it does the job. So since i know its just for all vacumm and cannot cause excess fuel flow that is great!! I may ja e the fubber hose attached improperly. I have it running too the top of the VRO. Where that small square secondary fuel pump is. It has two barbs. Maybe i have them crossed or not positioned correctlh at all. Does that has go to the crankcase/block directly?
 
Vacuum switch leaking = Plug that small fuel line leading to the vacuum switch temporarily. This makes it impossible to obtain a horn warning if a fuel restriction occurs... the only warning might be a collapsing Fuel Primer Bulb.

Fuel Primer Solenoid = Your explanation sounds proper... Red Lever turned to stop, over top of solenoid, pointed at other end of solenoid,

Poor Spark = Engine must crank over at least 300 rpm for stator to supply proper AC voltage to power-pack. As such, "All" spark plugs "Must" be removed to obtain the highest rpm available. A slow cranking engine results in weak, erratic, or no ignition/spark.
 
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