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cannot set timing

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Serj5150

New member
Hi everybody, just wanted to get you guy's ideas on what could be causing my problem. I have a 1989 johnson 140hp looper (J140TXCEB). i am trying to set the timing but the adjustment only moves it just a bit. I have checked the key and is not sheared. I have it at the shop and they are not sure why it is not letting them set the timing. Possible bad timer base maybe? Any help is greatly appreciated. Hopefully I can still go and get a nice trophy bluecat before the winter season is up.
 
Is your pointer set at true TDC? You need a piston stop tool to check/adjust ignition timing then you adjust throttle pickup to 3-5 degrees BTDC. To find true TDC turn the flywheel to 20 degrees BTDC and then install the piston stop tool into #1 plug hole and screw it in until it touches the piston make a mark on the flywheel and use any point to use as a reference. Turn the flywheel counterclock until it touches the piston again and make another mark on the flywheel using that reference point. Measure half the distance between the two marks and line the center mark to the reference. That is true TDC make sure the pointer is at TDC on the flywheel. If you use a piston stop tool be sure and disconnect the battery it will punch a hole in the piston if the starter enguages. All it takes is a little crease in the flywheel key to throw the timing way off if you have trouble finding true TDC install a new key and allways torque the flywheel down to spec before giving it fire.
 
That motor should have a 12amp system with cast in magnets so doubt its flywheel unless it had the 40 amp kit installed. Apparently it runs as your trying to set timing so are you trying to set idle or max timing???
 
Engine idle is controlled by ignition timing once you get the carbs dialed in adjust idle speed in forward gear in the water. It sounds to me like your engine sync is off. On the distributor is the throttle cam that opens up the carbs. On the water in forward gear shine the timing light at the marks on the flywheel and advance the timing to 3-5 degrees before top dead center. At that point the throttle cam should just be touching the throttle lever on the carbs and as you advance the timing the carbs should begin to open. If the carbs open too soon the engine will load up with fuel as it is not able to process the over rich mix in the cylinders. Did you check spark on all the plug wires with a open air spark gap tester? It must jump a gap of 3/8 inch on all the plug wires. Do a cylinder drop test while it is ideling, pull a plug wire and put it back on the engine should respond the same on all cylinders.
 
The real import part is checking your pointer is at true TDC it dont matter what flywheel you have sorry I got this mixed up with another engine I will check on the throttle cam for your engine.
 
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