1973 85hp evenrude . no spark #4 cylinder

[powerprochris]

Hi everyone . I have a 1973 evenrude 85hp with absalutly no spark to #4 not today while messing i did get spark briefly out of it but just as fast it vannished . all other cylinders have strong strong spark and when 4 did spark today it was as strong . but now nothing . i have switched coils around and same thing #4 no go . but coil works fine elswhere . has anyone had this problem before ? any help apr

 

[OBJ]

Re: 1973 85hp evenrude . no spark #4 cylinder

Welcome powerprochris!<br /><br />Look on the power pack and and find the lead from the timer base that says #4 Sensor. Swap this lead with another lead marked sensor and see if the problem follows. DO NOT TRY AND START THE ENGINE WITH THE LEADS SWAPPED...just test for spark. If you get the same thing, likely the power pack is bad. If the problem follows the #4 Sensor lead, problem is with the timer base.

 

[papasage]

Re: 1973 85hp evenrude . no spark #4 cylinder

could be a coil on that cylinder week

 

[powerprochris]

Re: 1973 85hp evenrude . no spark #4 cylinder

Ok gents thank you for your help . I have traced the problem to the powere pack . I have swaped #4 sensor wire with #1,2,3, and it gives each of them spark #4 on the powerpack doesnt give any coil spark . but i found if i tap the #4 spot on powerepack with handel on screwdriver it will give spark to #4 coil so i took the powere pack apart and cut the gelly around the #4 spot and wow i found a diode that is yellow has broken off on 1 side . so i soldered back and now i have spark in all cylinders . runns great . Thanks again for help guys . I'm going to buy a new powere pack and keep this one for a spare . Chris G.