Help!'93 9.9 Johnson won't start when warmed up

Honkin

Recruit
Joined
Jan 23, 2011
Messages
1
I have a '93 9.9 Johnson, and am the only owner. The motor will start cold and run well, but if I turn it off it won't start unless I let the motor cool down, which takes a couple of hours. Can anyone tell me where to start?
 

raczekp1

Lieutenant
Joined
Mar 30, 2010
Messages
1,327
Re: Help!'93 9.9 Johnson won't start when warmed up

Hi.
i would do in this way:
1. warm up the motor up to when its dificult to restart.
2.check the compresion imidietly
3.if compresion is good and even then check spark with spark tester.
if spark is bad, change spark plugs,spark plugs cables(2 cables and caps ofcourse)
after change check spark by spark tester.
if it not help powerpack or coils might be bad
sometimes its good to use transparent fuel hose leadind from fuel pump to carb, to see how fuel pump works and how much fuel pump during work.

i think this can happen if engin loose compresion becouse bad head gasket or powerpack/coil is working bad after warm up
 

levi_tsk

Ensign
Joined
Dec 26, 2010
Messages
907
Re: Help!'93 9.9 Johnson won't start when warmed up

yep what he said and id bet on a power pack they do that when they warm up -ALOT
 

raczekp1

Lieutenant
Joined
Mar 30, 2010
Messages
1,327
Re: Help!'93 9.9 Johnson won't start when warmed up

the best way to check powerpack is to swap powerpack from similiar motor(2 cylinder type,will fit powepacks from 4hp to 40hp) and take a run
 

kbait

Commander
Joined
Nov 13, 2007
Messages
2,446
Re: Help!'93 9.9 Johnson won't start when warmed up

I'm with the cd box failing, but there's also a trigger and a charge coil under the flywheel. I've heard they could also fail under higher temps. If you search this forum, you'll likely find a way to check them with a multimeter (after confirming no spark condition..) Good luck!
 
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