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johnson 48

C

catdog

New member
I have a 1990 Johnson 48 spl, model J48ESLESA that I am having ignition problems with. This model has a UFI ignition system. Can someone answer the following questions.
Does this model have SLOW mode?
Is the charging coil under the flywheel seperate from the ignition system? As long as the battery is charged, will this have any effect on the igntion system operation?
I replaced the ignition coil under the flywheel and the two wires coming out of it are solid brown and solid brown with a yellow stripe. I also replaced the power pack and the two wires that the ignition coil plugs into are solid brown with yellow stripes. Does it matter which wires you plug into? You would think that they would plug into like colors.
 
One thing for sure is ------------The ignition system works from the magneto.-------------If the battery is completly dead , you can start this motor with a rope on the flywheel.
 
The problem that I am experienceing is the engine starts and idles good. When you go to open up the throttle the engine revs right up like it should and then it starts bucking immediatly. It makes no differnec if the engine is cold or hot.Acts like a rev limiter is kicking in. The compression is 135 on both cylinders, new crankshaft seals on both ends, both Carbs cleaned and kits put in and yes the high speed jets and circuits are very clean. I ran a small wire threw and fluid and compressed air. I have installed a new power pack and it would not spark at either plug. Have another one coming. I put a new ignition coil under the flywheel because one of the wires was almost cut off from vibration. I pulled the brown wire off the overheat sensor and it made no difference in the way it ran. When it is acting up, you can pull off the lower plug wire and the engine will stop, but when you pull the top plug wire, you notice little difference and the engine will not stop running. The spark on that plug fires some but not all the time. I swaped the plug wires between them and the problem did not follow. I then reversed the coils and still the same issue. I sprayed mixed fuel into the top carb and it did not run any better. This engine is kicking my butt and it should not. Anyone have any other ideas to try. What am I missing? I don't understand what funtions the UFI ignition system controls.
 
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