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1984 Johnson bogging when given throttle

tinbender71

New member
Ok. I have a 1984 Johnson 70 hp J70TLCRD swinging a 3 blade 19 inch aluminum prop. The boat is a 15 Cajun bass boat, guessing about 1000lbs. I have searched and researched on this forum and others to figure out my problem. Starts fine, idles great. If I ease into the throttle, it will bog. If I quickly open throttle it bogs a little then takes off and runs great. WOT is @5100 rpm. When I back off the throttle, it still runs fine. If it was a four stoke v-8 I would think the advance is a bit lazy, but im not too keen on what a 2-stroke likes.

Here is what Ive done so far:
Check compression 123, 121, 128
Check spark jumps the 7/16
Rebuilt carbs, soaked each one over night with plugs removed.
Rebuilt fuel pump
New water pump and thermostat
All new fuel lines from tank to carbs, including primer and connector.
Decarbonized with sea foam
new plugs QL77JC4 Champion

I have seen many posts about this problem, but have not sound a solution. Any ideas?
 
Well I did borrow both a 15 and 17 inch prop. Turns out though that was not my problem. i ordered a Seloc book and did a link and sync, turns out my WOT advance was about 10 degrees shy of the 19 it is supposed to be. So it is set properly now and runs great.
 
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