Johnson GT200 rough idle and stalling

49golfr

Recruit
Joined
May 23, 2009
Messages
4
Had my 1994 Johnson gt200 rebuilt, cylinders bored, new pistons and rings, all carbs rebuilt, new water pump, etc. First time out started and ran good, good hole shot and top end. Followed break in procedures to a T. When I got back to harbor engine ran rough and stalled. Then hard to start. When started ran rough and quit, again hard to start. Tried to trailer boat about 20 times, each time when I applied throttle it quit. Had to winch it on trailer. Got home and flushed motor, started OK but still runing rough. I spent over $2800 on rebuild and am really upset. Any advice appreciated.
 

tx1961whaler

Vice Admiral
Joined
May 31, 2008
Messages
5,197
Re: Johnson GT200 rough idle and stalling

Yes, I'd be upset too. It needs to go back the person who rebuilt it to fix it, but I'd at least check the spark and compression before taking it in. If it's an ignition problem, you might have to pay for it, but anything else they should have to fix.
 

jtcarter

Petty Officer 1st Class
Joined
Apr 26, 2008
Messages
226
Re: Johnson GT200 rough idle and stalling

Your mechanic probably didn't take the time to sync your carbs very well. Seems like a reoccuring problem and one i'm sure the old wise men on this board are tired of answering. Its not a simple process however and takes some time to get right. I'm going to the lake in the morning to try and dial mine in, i know for a fact mine aren't adjusted right. Sounds like its loading up on mix and running rough. I'd take it back to your mechanic. This seems like a step a lot of people skip for whatever reason. I've even been told by a supposed OMC mechanic its damn near impossible without a syncronizing tool, like the ones some use on bike carbs. I'm going to give it my best shot without the sync tool in the morning, if not i'm going to borrow my mechanics and do it that way. I'm also starting to suspect i may have a exhaust leak getting under my cowl and choking mine out.
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: Johnson GT200 rough idle and stalling

Agree link n sinc, or trash got into the carbs, link n sinc is not that hard, it is just a step by step process, that has to be followed to the "T". i have never used a sync tool.
 
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