30 hp missing and sneezing

netting one

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Mar 23, 2010
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Dont really know the year but its a 30 md#j30rlenr ser#g03018367 my brother bought a boat with it on and its never been right. compression is 100 and 105 carb rebuilt,new fuel lines,new plugs. It doesnt do bad on the lake but coming to a idle it stalls. I ran it in the yard and its missing,shutting off and sneezing bad? Any idea of year or problems would help. thanks
 

ondarvr

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Apr 6, 2005
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Re: 30 hp missing and sneezing

Sneezing at an idle means it's running lean, possibly a plugged or restricted low speed jet.
 

ondarvr

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Apr 6, 2005
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11,527
Re: 30 hp missing and sneezing

Coils don't make it sneeze and they typically fail as the RPMs climb, if they work at all it's more likely they will at an idle, this doesn't mean they aren't bad though. You can check them, but checking doesn't mean they will test bad even if they are, look for cracks, or run it at night and look for arcing from the coil to the block. You can also use a spark tester, it should jump 7/16 or more with a bright blue spark, or use a test light and see if it fires each time it should.
 

steelespike

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Apr 26, 2002
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Re: 30 hp missing and sneezing

I have to second it is very likely a lean condition.Go through the carb again with careful check of all passages and jets.
 

netting one

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Mar 23, 2010
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Re: 30 hp missing and sneezing

I have to second it is very likely a lean condition.Go through the carb again with careful check of all passages and jets.

thanks again guys checked it last night and doesnt seem to be arching or spark jumping. Would the carb seem to put a miss in the motor? It really seems to be missing now and then?
 

jasper60103

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netting one

Petty Officer 2nd Class
Joined
Mar 23, 2010
Messages
112
Re: 30 hp missing and sneezing

If its sneezing in a barrel/muffs, it could be as simple as an adjustment. After carb rebuild did you adjust the slow speed needle?...
http://forums.iboats.com/engine-fre...sorted-carb-variations-joe-reeves-167352.html

I have tried to move the adj screw. I ran it in to it bottomed out and around 1 1/4 seemed to run ok there. It seems like it still has a miss so what i did is took of the plug wires slowly and on killed the motor right now and the other did run but not as good as with the wire back on.
 

jasper60103

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Sep 18, 2008
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Re: 30 hp missing and sneezing

I have tried to move the adj screw. I ran it in to it bottomed out and around 1 1/4 seemed to run ok there. It seems like it still has a miss so what i did is took of the plug wires slowly and on killed the motor right now and the other did run but not as good as with the wire back on.

Sounds like a coil is failing (i.e. the one that won't keep the motor running).

I would do a proper spark test. Then swap coils and see if the problem follows.
Warning. The spark plug wire that is not being tested should be grounded, else
you could damage the coil or powerpack $$.

Here's the parts diagram for reference...
Johnson Ignition Parts for 1992 30hp J30RLENR Outboard Motor
 
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