Re: Re Bored Evinrude 70, Carb Jet Change?
I believe I found the problem.<br />First of all, upon rebuild, found that the bottom carb was slightly gummed up. Gave 'em all a cleaning + kit and put them back on. Which actually leads me to my next question, I've found a number of posts on mixture. Now my manual states that there is no adjustments on my carbs, however there is, on the throttle linkage (starboard) side, just above and towards the stern of the engine there is an adjustable jet. Is it true that all should be seated in, then 1.5 turns out... 1/8 turns in till sputter then back out 1/4... etc... etc...???<br /><br />Secondly, upon performing link and sync, found that the bottom carb (trouble cylinder) linkage was loose... so while the top two carb throttle plates were opening, the bottom was still ever so slightly behind. This problem fixed. Curious if this would have contributed? VRO functions on crank pressure/vacum right? So if engine RPMS are up, but bottom carb throttle plate is slightly more closed that center and top?... hrmmm... guess not, if anything would run richer right?<br /><br />Thirdly, since this happened at WOT, the rebore fellas were quite adament about WOT timing!!! Saying it is absolutely imperative that this be set correctly. Of course I won't be able to do this until engine is nicely broken in and have verified (as you say voodoo) vro pump functionality. Until that time, will pre-mix 50:1 and mark oil tank as is suggested by so many.<br /><br />Last but not least, the manual suggests that for 1986 70HP's, if used at sustained high-speeds, different plugs should be used (assuming cooler plug).<br /><br />Thoughts? Comments? Suggestions?