Power Pack and/or Carbs

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takirb

Petty Officer 3rd Class
Joined
Apr 26, 2009
Messages
82
I have a 94 Johnson 48SP that wouldn't idle longer than 5 secs or so last year without me having to pull the lever up to keep the engine revved. On several occasions, it also wouldn't shut off by turning the key or pulling the safety cord. I'd often have to toss the throttle back and forth to get the idle to come back down and then let it stall out (slammed into a dock 1st time this happened). Also, for no reason, the tilt/trim would just start working outta the blue, even when sitting in the driveway, but i'd have to play around with the switch on the throttle and motor sometimes to get it to work before launching (IF it'd even work then).

So this year, i took it to the shop specifically asking for the carbs to be rebuilt. Instead, they said I had a bad power pack and one of the cylinders wasn't firing, stating this was the cause for the bad idle, tilt/trim issues, and not shutting off. Would a bad power pack really cause all these symptoms? I had a friend adjust the carbs for me last year and said he was unable to get it to idle at all using the low jets.
 
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jonesg

Admiral
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Feb 22, 2008
Messages
7,174
Re: Power Pack and/or Carbs

Ok so they swapped out the powerpack, now what?
What is it doing now?
 
T

takirb

Petty Officer 3rd Class
Joined
Apr 26, 2009
Messages
82
Re: Power Pack and/or Carbs

I can't get it on the water yet. Planned to this weekend but it's supposed to storm here in SC. I fear that i'll get halfway up the lake and run into problems again when under load for a bit. I don't have a choice but to put it out there, so i'll post results afterwards either way. Just curious if "all" my issues could be caused by a bad powerpack or should i spend an hour turning circles near the ramp just in case.
 
J

jonesg

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Re: Power Pack and/or Carbs

takirb said:
I have a 94 Johnson 48SP that wouldn't idle longer than 5 secs or so last year without me having to pull the lever up to keep the engine revved. On several occasions, it also wouldn't shut off by turning the key or pulling the safety cord. I'd often have to toss the throttle back and forth to get the idle to come back down and then let it stall out (slammed into a dock 1st time this happened). Also, for no reason, the tilt/trim would just start working outta the blue, even when sitting in the driveway, but i'd have to play around with the switch on the throttle and motor sometimes to get it to work before launching (IF it'd even work then).

So this year, i took it to the shop specifically asking for the carbs to be rebuilt. Instead, they said I had a bad power pack and one of the cylinders wasn't firing, stating this was the cause for the bad idle, tilt/trim issues, and not shutting off. Would a bad power pack really cause all these symptoms? I had a friend adjust the carbs for me last year and said he was unable to get it to idle at all using the low jets.
Click to expand...


I don't see any connection between the PP and the T/Trim and considering you have a problem with the throttle controller the T/Trim problem might be there too.

The PP will affect the running of the engine, misfire or complete loss of spark.
When mine went bad one side of the engine ( 3 cylinders) wouldn't spark.

So the throttle problem and T/T are a second issue.
You might want to pop the hood , remove air box and watch the throttle , make sure the throttle plates in the carb close down completely when throttle is closed, when WOT make sure they are all open horizontal in unison.

Best is to take a shakeout cruise, not too far away and see how it does, rough idle can be adjusted. Take some troubleshootin tools such as timing light to see if it loses spark if it dies.
 
T

takirb

Petty Officer 3rd Class
Joined
Apr 26, 2009
Messages
82
Re: Power Pack and/or Carbs

Sounds good, thanks for the advice! I never even thought about checking the throttle plates, i can do that from the driveway. Diagnosing electrical issues is where i get lost.
 
J

jonesg

Admiral
Joined
Feb 22, 2008
Messages
7,174
Re: Power Pack and/or Carbs

If the tilt starts running on its own, disconnect the main harness plug, if the tilt stops the problem is in the controller.
The little tilt switch has been described as "feeble",
hopefully I'll never find out .
You could try CRC aerosol elec cleaner from NAPA , or ratshack switch cleaner.
 
T

takirb

Petty Officer 3rd Class
Joined
Apr 26, 2009
Messages
82
Re: Power Pack and/or Carbs

Well, i took it out sunday and it still wouldn't idle correctly. It did however run 10 times better than it ever has, so new plugs and PP definitely didn't hurt! It will idle for about 15-20 secs before it finally dies, and i can set the fast idle lever in 1 position and it'll idle fine vs having to constantly fluctuate the lever like before. Next trip out i'll see if i can adjust the idle screw just a tad. Nonetheless, i was very pleased with it's performance so i'm a happy camper.

Tilt/trim gave me no problems, though it was intermittent before and i'm still in the habit of disconnecting the battery when back on the trailer. Also, it turned off right away each time I turned the key which was also a plus.
 
tashasdaddy

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: Power Pack and/or Carbs

suggest the OEM Johnson service manual, all you are doing is tinkering, with out proper direction.

your trim problem sounds like corroded dirty connections.
you also could have a bad ignition switch.
 
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