1968 55hp - Idles Very Poorly - Engine Re-rebuilt!

[atengnr]

Ok, in an attempt to make this more readable; this engine has been rebuilt, has new powerpack, wire harness, dist cap/rotor, newer carbs w/rebuild kit.

I took it out and it starts good, runs well anything off idle, but when warm the engine does not idle well, and will stall after 10 secs at idle (idle speed is fine). It has a cyclic-like miss every few secs - gives it sort of a bucking. Adjusting the low needles has no effect.

Note that this issue has existed even before the rebuild and all the new parts....

Any ideas on what could be the issue??

Thanks alot.

 

[atengnr]

Re: 1968 55hp - Idles Very Poorly - Complex Issue?

Re: 1968 55hp - Idles Very Poorly - Complex Issue?

any ideas would be greatly appreciated.

 

[atengnr]

Re: 1968 55hp - Idles Very Poorly - Engine Re-rebuilt!

one more bump

 

[scanman]

Re: 1968 55hp - Idles Very Poorly - Engine Re-rebuilt!

I'm thinkin... gimme a sec.

 

[scanman]

Re: 1968 55hp - Idles Very Poorly - Engine Re-rebuilt!

Maybe double check the timing? If it's off enough, it'll die at low rpms. Sounds like everything's new, so I'm thinkin something isn't set right. Just a guess, bud.

 

[atengnr]

Re: 1968 55hp - Idles Very Poorly - Engine Re-rebuilt!

Maybe double check the timing? If it's off enough, it'll die at low rpms. Sounds like everything's new, so I'm thinkin something isn't set right. Just a guess, bud.

Can you provide a quick overview of checking timing on this motor?

 

[oxbeast1210]

Re: 1968 55hp - Idles Very Poorly - Engine Re-rebuilt!

Please post back if you figure it out im having the exact same issue on my 1989 evinrude 150 tracker .

at most it will idle about ten seconds and then just die but if i move the throttle forward withing those ten seconds its find i did notice at lower throttle it also bucks every couple seconds ( kinda gains then loses a little power is what it feels like) makes the boat jump a litttle anything above 1/4 throttle is perfect and smooth does not miss at all. I sent my mechanic a text and he said that it probably needs the idle screw turned up its part of the timing procedure he suspects that since he adjusted it out of the water that it needs to be set higher for when its under load.
anyway ill update you when i figure it out and please do the same for me
I also noticed that the motor almost acts like it is flooded and wont start when i try to start it unless i have the little warm up ever up

 

[atengnr]

Re: 1968 55hp - Idles Very Poorly - Engine Re-rebuilt!

Please post back if you figure it out im having the exact same issue on my 1989 evinrude 150 tracker .

at most it will idle about ten seconds and then just die but if i move the throttle forward withing those ten seconds its find i did notice at lower throttle it also bucks every couple seconds ( kinda gains then loses a little power is what it feels like) makes the boat jump a litttle anything above 1/4 throttle is perfect and smooth does not miss at all. I sent my mechanic a text and he said that it probably needs the idle screw turned up its part of the timing procedure he suspects that since he adjusted it out of the water that it needs to be set higher for when its under load.
anyway ill update you when i figure it out and please do the same for me
I also noticed that the motor almost acts like it is flooded and wont start when i try to start it unless i have the little warm up ever up

Indeed, sounds very similar. I will definitely let you know if I make some progress. say again what your mechanic suggested?? I am pretty sure that my issue is not idle speed or air/fuel b/c I have fooled with these needles SO many times and I never found a spot any better than the factory 5/8 turn position.

 

[scanman]

Re: 1968 55hp - Idles Very Poorly - Engine Re-rebuilt!

I really don't have much info on that motor, Just goin on basic machanical principals. Search these forums for "timing" or "link & sync". I do know that motor uses breaker point style ignition. If yall review what I just went through with my 9.9, You'll see a dramatic improvement in my motors performance. Scroll down on this page & pay particular attention to posts 216 & up. It made a world of difference for me, & mine was bucking at idle, just like yall describe. Again, just a guess. I hope it helps!

http://forums.iboats.com/showthread.php?t=441949&page=9

 

[oxbeast1210]

Re: 1968 55hp - Idles Very Poorly - Engine Re-rebuilt!

im not sure if your motor is set up the similar to mine but the lever that pushes or pulls the throttle cam has a screw that you can turn in or out,
clockwise will raise idle speed counterclockwise will reduce it . he said that it has to be done in the water to get it just right . Please do not make any other adjustments unless you know what they all do mine has about 5 adjustments in the area one is minimum spark advance,cam follower pick up timing,cam follower , idle speed , and wide open throttle stop you dont really want to mess with any of the timing unless you know how . the only he told me to mess with is the idle speed screw. I told him id see him tomorrow since i don't want to mess anything up lol im going to have him show me how to do it and hopefully it sloves my issue i just had the carbs rebuilt , fuel pump replaced, and spark and compression all checked so hes confident its just a simple adjustment .
ill keep you posted