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    1978 Johnson 140hp running rough. Need advice

    Definitely doing things on a bit of a budget. I can try and find another head, but it seems a bit hard to get a starboard head
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    1978 Johnson 140hp running rough. Need advice

    So no saving that head?
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    1978 Johnson 140hp running rough. Need advice

    Ive had people say you just beed to smooth out the high spots and run it? And they are abundant, but if i can reuse this set of heads id rather.
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    1978 Johnson 140hp running rough. Need advice

    Cleaned it
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    1978 Johnson 140hp running rough. Need advice

    Havent had much time to mess with it, but i should look back into the ignitiontiming. Been cold here. Did get the parts engine in the garage and pulled the head that included the bad piston. Is that head salvagable?
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    1978 Johnson 140hp running rough. Need advice

    So yeah I did set both blades fully closed at idle. And atleast watching them they do appear to be opening at the same time. As far as the timing side goes I'm not familiar enough with it to know where all that needs to be set. Im familiar with timing in the automotive sense. Small blocks...
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    1978 Johnson 140hp running rough. Need advice

    Ive been through them a few times haha, But yes I've been needing a reason to buy a Ultrasonic cleaner. Ive shot cleaner every direction possible and its all flowing. Surprisingly simple carbs really. No adjustments other than the throttle blades. Bass fishing i do alot of spot hopping. And...
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    1978 Johnson 140hp running rough. Need advice

    Its runs fine at WOT. It just struggles to go between idle and WOT. Say I'm sitting idling and want to go to part throttle for any reason. Or loading on the trailer. Or if I'm idling and go to blast off the motor just falls on its face and stalls. But if i hold the choke and let it load up...
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    1978 Johnson 140hp running rough. Need advice

    First time i used the kits the fella i got the boat from gave me. aftermarkets. I later used OEM kits and that helped alot. New welch plugs and alittle sealer. Currently It'll fire right up. Idles good. Now what happens MOST of the time now is the engine really struggles to transition idle and...
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    1978 Johnson 140hp running rough. Need advice

    You sir hit the nail on the heads. So after a couple trips it's done decent. Still has some issue just falling on its face when you punch it from idle. I decided to recheck compression with a new tester. Got right at 115 on each cylinder. Thought the slight increase was interesting but I...
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    1978 Johnson 140hp running rough. Need advice

    Little update. Had time this week to get the carbs back on. Fired it up on water horns and its back to idling good on all 4 again. Will take it to the lake this weekend to test in the water as again.
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    1978 Johnson 140hp running rough. Need advice

    Well I've found some OEM kits local. And yeah I can tell it's picky. For a moment yesterday it was just about right. The off idle was decent and the idle was steady. Maybe the plugs were crappy and undersized or maybe I'm just not knocking them in hard enough to expand them fully.
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    1978 Johnson 140hp running rough. Need advice

    On the topic of float height. I read the idea is just to get the end of the float opposite the needle just above level with the body of the carb correct? And what was the sealer recommended for the welch plugs? Recall reading about it but can't seem to find that post again
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    1978 Johnson 140hp running rough. Need advice

    Well I have noticed there throttle shafts do have some play. I'm gonna source some good rebuild kits. Get it all back together and then I heard someone say to try some axle grease around the shafts to help determine if they are causing an issue.
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    1978 Johnson 140hp running rough. Need advice

    I have no reason to pull the flywheel. Spark is strong and all indicators point towards a fuel issue. Like I say it was running pretty good. Id say the issue on the water was that Welch plug getting loose then coming un-seated again. I wouldn't think they were still making OEM kits for the...
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    1978 Johnson 140hp running rough. Need advice

    Well the problem was pretty simple. Welch plug didn't stay put. Was hanging out the hole. I used a kit supplied with the boat. Honestly didn't like it. What kits are everyone using? And could I fit this engine with another v4s carbs that are adjustable idle mixture?
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    1978 Johnson 140hp running rough. Need advice

    Kinda frustrating I know it's a fuel issue. the carbs are "clean". All circuits blow through fine with carb cleaner. On the lake when it was running on just the bottom two the choke for a second would cause the top two to pick up and when I got it home and ran it on the horns it did it again...
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    1978 Johnson 140hp running rough. Need advice

    Going to wait till it gets a little darker test spark gap. But it seems like it's isolated to the upper two cylinders Update. Spark on all 4 coils jumps 1/2" pretty easily.
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    1978 Johnson 140hp running rough. Need advice

    Well I took it to the lake and initially everything seemed pretty good. Idle was decent still hiccups a little till it was warm. Transition from idle to throttle just fine. Was pretty happy with it then it just did a complete 180. Didn't want to idle didn't want to go from idle to wide open...
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    1978 Johnson 140hp running rough. Need advice

    Oh i know. My Buddy went through 3 power heads before he found one decent one. I think i may already have it fixed however. And I THINK it was due to crappy carb bowl gaskets. I took it back apart (top carb). Popped those welch plugs out and those little holes for the idle circuit looked...
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