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1975 Johnson pops or backfire thru exhaust while idling

S

slimdaddy

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I have a 75 johnson 115 hp it doesnt want to idle unless I speed it up some then it pops or a backfire on the muffs but when I have it the water it will run great at wot Ive cleaned the carbs on it didnt help so it must be electrical so what could it be powerpack or coils can some body help me out where to start I have another complete powerhead thats 85 hp for parts
 
79 evinrude 175 hp. same problem. plus backfiring, shears woodruff key on flywheel. have rebuilt carbs, new coil, new power pack. no help. finnialy figured out the problem MAY be flooding. the gas pours out of the middle carb. The rebuilt kits were omc brand think the needle valves were defective. Just ordered new needle valves. will let you know if this works.
 
virgffisch said:
79 evinrude 175 hp. same problem. plus backfiring, shears woodruff key on flywheel. have rebuilt carbs, new coil, new power pack. no help. finnialy figured out the problem MAY be flooding. the gas pours out of the middle carb. The rebuilt kits were omc brand think the needle valves were defective. Just ordered new needle valves. will let you know if this works.
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Thank you mine doesnt seem to flooding no gas coming out anywhere but let me know how it works out for ya
 
Sounds like you have a carburetor running lean. If so................

Remove the craburetor face plate. With the engine idling and the problem present, stick two fingers into the carburetor throats, one at a time of course. When the engine smooths out, you've found the offending carburetor which will require a different size idle jet to enriched the fuel flow.
 
1975 115hp Johnson... you changed needle valves? What needle valves?

Did you try the two fingers in the carb throat test? If so, what were the results?
 
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