70ESL-74M 70hp Johnson no power

[jts76240_2005]

OK its me again..<br /><br />Here goes, I have this motor and have had an issue with a lack in power. It will run up to about 25% power and wont go any more. I have changed the plugs, power pack, checked the coils, cleaned the carbs, installed a new tank and fuel lines. Also have a rectifier on order cause batery stopped charging to. I am now at a total loss?<br /><br />When I first started this venture the motor had no spark on #3. After replacing the power pack it came back and ran great for a couple of hours. Now all of a sudden I have the power problem again but at idle I still have spark on all three. When I take the boat out it will idle fine with no miss. As I move into the throttle is starts to rev up. When i get a 1/4 throttle into it thats all it has. If I leave the throttle at full it will pulse like it wants to rev up but falls right back off. Is there something I have missed. I am ready to accidently loose this thing in the lake.

 

[Goodoleboy]

Re: 70ESL-74M 70hp Johnson no power

I would check to see if fuel pump is working right.<br /><br /> Make sure you have no air leaks, any place in your lines.<br /><br />You can also have a problem still in your ign. system. I would almost bet thats where your problem lies.<br /><br />Link and sync. is extremely important also.<br /><br />Good luck!

 

[jim_in_day]

Re: 70ESL-74M 70hp Johnson no power

Hi, link and sync is most likely the problem, i had the same problem with my 70hp 76 johnson, went thru power pack, trigger, coils, fuel pump and rebuilt the carbs 4 times, at about 1/2 throttle it would die. Finally did a link and sync and found that the ignition timing was 4 degrees off. needless to say, if the carbs are starting to pickup with the timing that far out, it won't run right if at all. Set your initial timing to 0 degrees as the carb just starts to pick up, and make sure your wot timing is at 17 degrees