johnson venom 200

[snookhansel]

Hi i am new to the forum and new to boating also so be patient with my dumb questions. I recently became the owner of a 20' bass boat it has a 200hp venom. I was told by my local marine not to trust the ioling system so i premixed my fuel. I started the engine in my driveway using the water hose clamp on thing, see told you i was new to boating. The motor idled and ran fine. when i took it out i got it to rev up and run down the water twice. both times once the rpm's were up it ran fine. After 5 hours on the water i gave up. The motor would idle then act like it would run out of gas. At times i could get it to idle, but when i put it in gear it would flutter and die. When i brought it home i checked it in the driveway and it ran fine again. I dont know why it will not run when i put it in the water. If anyone can help i can give more information to the things i tried. It almost seemed like after the exhaust was lowered under the water the thing just didnt want to run.

 

[snookhansel]

Re: johnson venom 200

After reading more on problems similar to mine i am wondering if it is my vro pump. i did leave the vro pump hooked up and run premix but i am not getting massive amounts of smoke like i would expect. could i be sucking air through the oil line from the oil tank? i unplugged the primer solinoid it seemed to idle logner but this could have been my imagination. Still dont understand why it runs in my driveway and not in the water. This was my uncles boat and he said this problem started when he was running the boat ona regular basis, so it being a problem from long term storage just dosnt make sense.

 

[jonesg]

Re: johnson venom 200

On the hose there is no load, in the water the load requires more fuel,
the problem is very likely clogged carb jets, the fix is to order carb rebuild kits. Get a factory service manual, its quite simple to do yourself.

www.outboardbooks.com

 

[snookhansel]

Re: johnson venom 200

thanks for the reply

 

[daselbee]

Re: johnson venom 200

I hope you can get it running with help here.
Like jonesg said, there is "load" or exhaust backpressure created when the engine foot is submerged in water, and it changes the running characteristics of an outboard. For instance, an engine idling on muffs in the driveway will idle at about 1100 rpms, but in the water in gear it should be around 700.
So. I suggest some massive reading of the posts here, and get an original OMC service manual, not a Clymer or Seloc.
Now, for some suggestions...you need to eliminate some of the subsystems as being the problem.
Do a spark test as outlined MANY MANY times on this forum. That will help eliminate the ignition system.
Check your compression as outlined MANY MANY times on this forum. That will help eliminate mechanical cylinder damage.
Then, you need to be absolutely sure your fuel delivery system is right. A very likely culprit is dirty, clogged carbs. Bad gas, air leaking into the fuel delivery system, mis-adjusted idle screws, link and sync out of adjustment, all this could be part of the problem. We will have to step thru these things until the solution is found.

It will help if you can get a tank, barrel, or something to run this engine in instead of muffs.

Also, it sounds as if you have NOT disabled the VRO system properly, because you are worried about pulling air in from the oil line. The oil line should have been disconnected at the pump, and plugged securely as part of the VRO disabling procedure.

The answer to your problem is surely covered in other posts on this forum. Happy reading!!!

 

[coolguy147]

Re: johnson venom 200

oh a impeller change would be peace of mind if u dont know when it was changed last

 

[snookhansel]

Re: johnson venom 200

Thanks for the response to my post. I did a compression test, and all the cylinders read from 103 to 98. I went to buy a service book and they didnt have one in stock so i have one on order. I did buy this johnson system cleaner and run the engine as i pumped it in through the primer soleniod. let it set for three hours and restarted. This stuff did make difference because the motor started up after setting better then it ever has before. what is the best method for plugging the oil feed to the pump? I was thinking of getting some kind of rubber sleeve and a clamp, or cutting the hose and clamping a bolt with a shoulder in the tubing. i live 2 miles from a boat ramp so i can take the boat down and drop the lower unit in the water for a real world test. iwill keep you guys posted on my progress, again thank you for the help.

 

[snookhansel]

Re: johnson venom 200

i took the boat out and it did fine. It did die on me a couple of time when i put it in gear. I would restart it and put it back in gear and hammer on the gas and it would take right off. then i could slow down and let it chug away. These were minor problems to me i think i can live with an occasional hiccup.