Anyone own a Johnson "venom" 200hp ?

Status
Not open for further replies.
Joined
Jun 18, 2007
Messages
1,754
Location
north carolina
we have a Javelin bass boat. i think its a 1997 model. anyway it has a johnson venom 200hp on the rear and it smokes like a chimney.. i cant get to much info on it. i have read that they smoke like that and that its part of the beast but really i dont know.. any ideas? she runs pretty good and will fly if wings were attached. every now and then you get a little skipping when cruising between 30-40 mph it will radomly feel like the motor is skipping. we replaced plugs, fuel filter and is serviced every year or every other year.

could the skipping be the lower end? maybe its not leveled right at the speed its going?

also the smoke, what can be done? the (due to lack of terms) oil and fuel mix part was replaced 2 years ago. but it still smokes like crazy. any idea?
 
Sounds like it's over oiling.
Not sure it's adjustable. Even with generic 2 cycle injector oil, smoke should be minimal.
Check with a different mechanic.
 
The oiling system on that vintage were problematic. I saw many fried powerheads with those while in the industry. At the time boat dealers recommended disconnecting it and running a 50 to 1 oil mix in the fuel tank. At least your's is over oiling as opposed to not oiling at all.
 
yeah i cannot adjust the oil to gas bc its "auto" (cant remember the name of the part that mixes)

he uses supertech and or johnson oil to mix

yes she smokes like a chimney
 
The carburated (sp???)(those that do not have fuel injectors) Johnson/Evinrude's use a combination fuel and oil pump assembly. One side of the assembly delivers the fuel and the other side delivers the oil. When the pump develops an air leak (usually the seals around the plunger or the pump diaphragm on the fuel side) the result is over-oiling. If the oil side diaphragm leaks, the result is under-oiling.

You have some options: (they all involve removing the assembly from the engine)

1. buy a rebuild kit and rebuild your current pump assembly
2. buy a new or factory rebuilt pump and install it
3. buy a new or rebuilt 'fuel only' pump and pre-mix to 50:1 manually in the fuel tank
4. disconnect the oil pump side of your current assembly and pre-mix (note that this will not repair any existing leaks in the current pump

Good luck!
 
Originally Posted By: mikeg5
we have a Javelin bass boat. i think its a 1997 model. anyway it has a johnson venom 200hp on the rear and it smokes like a chimney.. i cant get to much info on it. i have read that they smoke like that and that its part of the beast but really i dont know.. any ideas? she runs pretty good and will fly if wings were attached. every now and then you get a little skipping when cruising between 30-40 mph it will radomly feel like the motor is skipping. we replaced plugs, fuel filter and is serviced every year or every other year. I had a 2000 Johnson 150 hp Ocean Pro. The carb mixture screws were fine pitch allowing one to really fine tune the idle mixture. Tuning six cylinders takes some practice. It you're not comfortable with this, don't touch it. People have cooked powerheads by shutting off idle circuits. Turn the mixture screw in slowly allowing the the change in mixture to travel to the cylinder. Stop when it starts to drop or skip. At that point back the screw out 1/4 turn. and go on to the next cylinder. If you can start the outboard when it's cool and don't need to hit the choke, you're likely too rich, and are wasting fuel. When leaned porperly, throttle response can be brutal. Find ONE oil and stick with it as changing oil can upset the calibration. Trust me! Now for the smoker! I have seen 150 hp, and smoke like crazy (OMC's) after they were run, shut down, and then re-started again. A knowledgable marine mechanic told me he thought it had to do with how the crank was oiled. Perhaps the crankcase is puddled with oil at shutdown. Skipping could be an overly rich cylinder (idle circuit)starting to fire as the carb throat starts to open, or a carb out of sync. The carbs on my 150 were two triple throats. It helped with the sync problem. Sorry about the mess. I didn't want to re-write after I found that I interrupted the script. Sooooooooooooo sorry. hope this helps.

could the skipping be the lower end? maybe its not leveled right at the speed its going?

also the smoke, what can be done? the (due to lack of terms) oil and fuel mix part was replaced 2 years ago. but it still smokes like crazy. any idea?
 
i talked with a knowledable guy about cylinder #2, the smoking issue, and the "skippping".. let me know what you guys think..this is his reply

Hey Mike,
The reason to increase the size of the #2 jet is to help cool #2 cylinder. By going up 2 sizes the small increase in fuel flow will actually lower the temperature of that cylinder. As far as the smoking goes I would have a look at the recirc valves they scavenge excess oil/fuel and return them to the crankcase. If you look at your motor you will notice 3 small hoses from each cylinder leading to the front half of the motor (intake manifold) you can remove these and let them soak in a wash of isoprophyl alcohol for a few minutes and use an old tooth brush to clean the screens. They are one way valves and can be tested for proper operation by using a syringe ( I use a turkey seasoning injector) and a small diameter hose placed on the nipple. You should be able to draw some of the alcohol through the screen side but not be able to push any back through. If you can you need to replace that valve. They are about $12.00 each.

That sounds more like a surging issue, while you are testing the recircs, inspect the throttle body linkage and look at the very top right hand side where the linkage meets the timing arm. there should be a clear plastic roller covering the solid black roller. More than likely it is gone. You will need to replace that too.
At today's prices 89 is fine, but adding some seafoam sure wouldn't hurt getting the insides cleaned up too.

Good luck,

Fred
 
Status
Not open for further replies.
Back
Top