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Johnson 70hp no full throttle

O

Odomrusty

New member
Good afternoon all, I have a 1979 Johnson 70EL79, when I try to go to full throttle I get 7mph. I can reach back and grab the choke throttle linkage and the engine will rev up and the boat planes out great. The carbs have been rebuilt, new coils, stator, fuel lines and fuel pump. I’m not sure why pulling the choke linkage makes it run better. Do I have a spring in the wrong place or is there another issuse?
 
Something in the carburetors was missed----Stop running the motor until you find the cause.-----A plugged / partially plugged carburetor means you might be starving a cylinder of oil too.----And post the actual compression values here.
 
You'll need to get carb kits to have all the parts you need. I've attached a blown up diagram of your carbs. You'll need to remove pulugs #4 and #5 and clean out the passage behind those plugs. The kit has the replacement plugs. Be sure to remove and thoroughly clean out the jets #27 and #35. Be sure to adjust the float levels to the recommended height. Soaking the carbs overnight in a gallon bucket of carb cleaner with a basket strainer in it that you can purchase at most automotive parts stores is a great start. Then using a compressor to force air through all passages includin the jets is a must. If you don't have access to an air compressor, spraying aerosol carb cleaner is the next best thing. Hold the jets up to a light and you should see a perfectly round hole. If not, you're not done cleaning it out. Mark the carbs when you take them off. They're all different.
 
Oldsaltydog said:
You'll need to get carb kits to have all the parts you need. I've attached a blown up diagram of your carbs. You'll need to remove pulugs #4 and #5 and clean out the passage behind those plugs. The kit has the replacement plugs. Be sure to remove and thoroughly clean out the jets #27 and #35. Be sure to adjust the float levels to the recommended height. Soaking the carbs overnight in a gallon bucket of carb cleaner with a basket strainer in it that you can purchase at most automotive parts stores is a great start. Then using a compressor to force air through all passages includin the jets is a must. If you don't have access to an air compressor, spraying aerosol carb cleaner is the next best thing. Hold the jets up to a light and you should see a perfectly round hole. If not, you're not done cleaning it out. Mark the carbs when you take them off. They're all different.
Click to expand...
Thank you so much for your time and knowledge.
 
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