1987 225 johnson sneezing at idle

ctrahan18

Cadet
Joined
Jul 5, 2010
Messages
9
i have a 1987 225 Johnson vro that sneezes at idle. i change the plugs i had the carbs cleaned and change the reeds.i drained all fuel and replace it with fresh fuel. it only sneezes at idle anything over 1000rpm's it doesn't sneeze. :confused:
 

Dhadley

Supreme Mariner
Joined
Feb 4, 2001
Messages
16,978
Re: 1987 225 johnson sneezing at idle

Why did you change the reeds? Did you replace them with factory reeds? Did you get the reed gaskets on correctly? Check the butterflies to make sure they're all seated at idle. A little tricky on those motos, especially the bottom ones on each side.
 

ctrahan18

Cadet
Joined
Jul 5, 2010
Messages
9
Re: 1987 225 johnson sneezing at idle

Why did you change the reeds? Did you replace them with factory reeds? Did you get the reed gaskets on correctly? Check the butterflies to make sure they're all seated at idle. A little tricky on those motos, especially the bottom ones on each side.
i change the reeds because it was sneezing. i did replace them with factory reeds and put a new gasket i make sure i put it one right and the butterflies are seated at idle. compression is at 95 on all cylinders. anything else i can try?
 

jonesg

Admiral
Joined
Feb 22, 2008
Messages
7,174
Re: 1987 225 johnson sneezing at idle

Are all the carbs sneezing?
Isolate it by putting 2 fingers in each carb throat by turns.
Look for leaks around carb.

If no external problems found...
I would rebuild that carb with a kit, pay attention to the idle jet and nozzles.
A small wire run through the jets will ensure they are clear.
 

backyard mechanic

Petty Officer 1st Class
Joined
Jan 6, 2009
Messages
203
Re: 1987 225 johnson sneezing at idle

If I understand your wording, "sneeze" is like a backfire through the carbs and understandably you'd want to check or install new reeds. My thinking was a sneeze is caused by an improper mix (adjust carbs to provide more fuel at idle) or a float level issue.

Going back to the basics it's worth while to reset your sync and link just to be double sure you are right on there. If the timing is a little slow, add a degree or so to the primary pickup. You should be able to tell fairly quickly if the sneezing stops with a little timing adjustment.

My Merc 115 sneezed at idle and the carbs were set up and linked up perfectly. I even went as far as to readjust the floats but that didn't do it either. Merc (on line) said to increase the primary timing a few degrees. I did and the sneeze stopped.

Hope that works for you...:)
 

d.boat

Chief Petty Officer
Joined
Sep 19, 2008
Messages
520
Re: 1987 225 johnson sneezing at idle

I'll give my standard reply anytime I see the words sneeze and idle.

Check, very carefully, the entire fuel and oil system for any air leaks. I had an 80s V6 that was running great except for an idle sneeze. We found that the oil inlet on the fuel pump (oil injection had been removed) had been plugged poorly and was leaking air into the fuel pump. We plugged it better and the sneeze went away like magic.
 

cougar1985

Lieutenant Junior Grade
Joined
Oct 7, 2005
Messages
1,023
Re: 1987 225 johnson sneezing at idle

one more post to tell my tale of woe!my motor was ill running for a little while ,stalling at trolling speeds ,sneezing upon start up and warm up.to make a long story short dont neglect your female gas connection to the motor ,they do wear over time and will, i say, will cause you all sorts of grief .you should hear a very definate click when you plug it in if not chuck it away and get another .all my issues are gone since i replaced mine ,just something to think about!sometimes the problem is so minor we overlook it for a bigger explaination ,i hope its the case for you.
 
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