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1992 40 hp won't idle or top end.

wfw2bar

New member
1992 40 HP johnson will not idle or reach top speed in gear. I winterized the engine last winter, fogged and stabil. Started it up w/o a problem but will not stay running when I drop the throttle down. I was able to get in gear but the engine will only go half speed, 13' whaler not even planing.

To start the engine I have to give it about half throttle and choke the engine. I bring the throttle down to about a third and the engine will shut off if I press in the key choke the engine will stay on but it begins to race.

Replaced inline fuel filter
Put OMC tuner thru engine left if over night and ran the engine
sprayed carbs with carb cleaner.

Any quick fix? Is it the carbs or something else. Do I pull the carbs and have them rebuilt.

Thanks
Walt
 
Re: 40 hp won't idle or top end.

take the carb off and clean the high speed jet and the idle jet. also make sure that when youpull the choke all the waythat the butterfly is exactly level. any restriction can cause these problems. also check your plugs to see if they need to be cleaned or replaced. you can also check your spark as you check your plugs but it really sounds like your carb needs to be cleaned. i just went throught the same thing and found expert advise on this forum
 
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Re: 40 hp won't idle or top end.

Already installed new plugs no change. I never worked on carbs before. Pulled them off my 200 and had them serviced. Do I just breakdown and clean or buy a kit. I have the manual how difficult is it.
 
Re: 40 hp won't idle or top end.

it shouldnt really be that difficult really as i am still learning myself..........you can do either or ....or you can do both. i have always had good luck with just taking them apart and let them soak in gunk carb cleaner and soak.....the one with the tray that you can set them in....i would always let them soak for about a day or two. but make sure that you dont put the gaskets or any little rubber o-rings in there as it will cause them to deteriate and fall appart not allowing you to "re-use" them. after it had soaked i would take a torch tip cleaner and make sure the jets are not clogged. making sure to get the high speed jet in the bowl. you might have to get creative and grind down a flat head screwdriver to fit inside the "bowl hole" to be able to get to the jet. be careful not to mess up the threads in the bowl trying to get the jet out. also be careful not to try to oversize the hole with the tip cleaner ...you might cause a bur in the brass jet and then youwould have to buy a new jet.once you breakdown everything and clean it really good, blow it out with compressed air. install carb and check for operation. if that doesnt work do it all over again but rebuild carb. installing new needle valve, float pin, idle jet and even high speed jet if you buy the good carb kit. you can but a good carb kit off this site. i hope it works out bossman. just remember to put all your little parts in a seperate plastic bag while the carb is soaking so it doesnt get lost or kocked over or eaten buy a little child. some parts are very hard to find and expensive to replace. good luck.
 
Re: 40 hp won't idle or top end.

well just finished cleaning carbs. Some minor gunk but not to bad. Any how no luck still having the same problems. I will check spark next. would running on one cylinder cause these symptoms. Any sugestions.
 
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