johnson venom problems ugghh!

jmcoop

Recruit
Joined
Jul 24, 2005
Messages
5
-j200stledm '96<br />-new lower unit (out of the box)<br />-fuel lines all just replaced including from tree to carbs<br />-new fuel ball<br />-no antisiphon in tank (on board)<br />-new fuel filter as per omc manual<br />-removed h2o seperator<br />-compression; 105,104,109,103,102,100<br />-new plugs <br />-advancement adjusted 1 week ago by mech<br />-idle adjusted 1 week ago by mech (700rpm)<br />-checked at 1/2 mark a.o.k.<br />-new vro at end of '03, disconnected oil injection and running 50:1 premix as per mech of previous owner<br />-power head rebuilt in '01 due to disconnected oil line when transum refinished hense why above done<br /><br />problem;<br />starts well. sputters a little in idle and dies. leave dock and put motor into gear and it dies sometimes, not usually after it is warmed up at almost wot. tried to pull a skier yesterday and put into gear and then hit the throtte and it died 4 times. had to gradual throttle up and then hit it. what to do??
 

Dhadley

Supreme Mariner
Joined
Feb 4, 2001
Messages
16,978
Re: johnson venom problems ugghh!

Welcome!!<br /><br />Has it been sitting? Sounds like a good carb bath may be called for.
 

jmcoop

Recruit
Joined
Jul 24, 2005
Messages
5
Re: johnson venom problems ugghh!

nope it has not been sitting. it came out of storage in may and we have had this type of problem since last year. i took carbs apart and checked the floats and the seats but unfortunately this was not the issue.
 

Solittle

Fleet Admiral
Joined
Apr 28, 2002
Messages
7,518
Re: johnson venom problems ugghh!

Checking the floats and seats is not a thorough cleaning & rebuild - My bet goes to crud in the carbs.
 

jmcoop

Recruit
Joined
Jul 24, 2005
Messages
5
Re: johnson venom problems ugghh!

no problem<br />i will clean them thoroughly. <br />what would you use to clean them?
 

jmcoop

Recruit
Joined
Jul 24, 2005
Messages
5
Re: johnson venom problems ugghh!

no problem<br />i will clean them thoroughly. <br />what would you use to clean them?
 

jmcoop

Recruit
Joined
Jul 24, 2005
Messages
5
Re: johnson venom problems ugghh!

no problem<br />i will clean them thoroughly. <br />what would you use to clean them?
 

MarkHPCA

Petty Officer 2nd Class
Joined
Jun 2, 2004
Messages
145
Re: johnson venom problems ugghh!

Any auto carb cleaner. Take everything apart and soak well (I don't know about yours but my 120 has plastic bowls and the don't recommend soaking these) Blow out ALL the various passages preferably with compressed air and re-assemble with new gasket kits. <br /><br />While you'r at it check the fuel lines to the carbs , mine were getting hard so I replaced them too. Also you may want to clean out the recirculation valves while everything is apart and easier to reach. Carefull not to break any of the plastic hose fittings.
 

diggs

Seaman Apprentice
Joined
May 8, 2005
Messages
37
Re: johnson venom problems ugghh!

Hey jm coop did the carb rebuild/cleaning do the job. Have the same problem with mine.
 

seahorse5

Rear Admiral
Joined
Jan 24, 2002
Messages
4,698
Re: johnson venom problems ugghh!

For a quick check, open up the idle adjustment mixture screws one additional turn. They should be 5 to 6 turns open for most motors.<br /><br />Make sure each thermostat is warming up each cylinderhead to around 140 degrees at idle.<br /><br />The prop should allow the motor to turn up to 6000 rpm with an average load of fuel and folks.<br /><br />The next time it starts to die on acceleration, hit the keyswitch in to "choke" it. If the motor picks up, then you definitely have carb problems.
 
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