1985 Johnson 150 - VRO or Carb Problem?

[lowbud]

Recently, when I try to run above 3000 rpm, the engine bogs and slow down. Like it is not getting enough fuel.<br /><br />I replaced the fuel filter and inspected the in-line filter on the outboard and it still does this. I have tried pumping the oil bulb when running and this makes it worse. But if we pump the fuel bulb, the outboard runs great. I can run full out. No bogging.<br /><br />Would this be a VRO problem? The outboard has run great for years. The carbs were rebuilt a few years back.<br /><br />Thanks for the help.

 

[DJ]

Re: 1985 Johnson 150 - VRO or Carb Problem?

But if we pump the fuel bulb, the outboard runs great.

That tells you it is starving for fuel.<br /><br />I would first try running it off of a known good six gallon tank and hose.

 

[cvx35]

Re: 1985 Johnson 150 - VRO or Carb Problem?

DJ's right about that. You should have 3/8s id fuel line and connectors. Also, check the pickup tube in your fuel tank. Might not be big enough. Walmart is known to sell tanks meant for smaller engines.

 

[angus63]

Re: 1985 Johnson 150 - VRO or Carb Problem?

Clogged or closed vent? bad antisiphon valve? bad check valves in fuel bulb? and the ever present air leak btween the tank and the VRO can all cause the starvation. Also, a restriction anywhere between the tank and fuel bulb can also cause this. Before you start dumpin bucks on replacing the fuel system, try another tank and hose to verify like DJ proposed.

 

[lowbud]

Re: 1985 Johnson 150 - VRO or Carb Problem?

Thanks for the tips.<br /><br />We tried running the outboard with the gas fill cap off and still the same problem. Next step is to look for some air leaks and/or change my bulb.

 

[lowbud]

Re: 1985 Johnson 150 - VRO or Carb Problem?

Well summers over and I am still no further in solving my problem. I do have a few questions. I did try the portable fuel tank with the same symptoms - bogging at high rpms.<br /><br />Would a 1985 Johnson 150 have a SLOW mode? I do not believe it does but want to confirm.<br /><br />When checking out the outboard on muffs the engine is not running right. It kind of picks up speed and then drops, over and over. What would this be an indication of?<br /><br />When I pull off the spark plug wires off the lowest cylinder (each side) I see the biggest change in rpm. Is this typical or an indication of my problem?<br /><br />Again to pumping the bulb. At idle when running rough, if I pump the bulb the engine picks up speed and runs fine. What is this telling me?<br /><br />What would be a good next step? Answers to the above questions would be appreciated. Thanks.

 

[Melvin Hatcher]

Re: 1985 Johnson 150 - VRO or Carb Problem?

Originally posted by lowbud:<br /> Well summers over and I am still no further in solving my problem. I do have a few questions. I did try the portable fuel tank with the same symptoms - bogging at high Roms.<br /><br />Would a 1985 Johnson 150 have a SLOW mode? I do not believe it does but want to confirm.<br /><br />When checking out the outboard on muffs the engine is not running right. It kind of picks up speed and then drops, over and over. What would this be an indication of?<br /><br />When I pull off the spark plug wires off the lowest cylinder (each side) I see the biggest change in rpm. Is this typical or an indication of my problem?<br /><br />Again to pumping the bulb. At idle when running rough, if I pump the bulb the engine picks up speed and runs fine. What is this telling me?<br /><br />What would be a good next step? Answers to the above questions would be appreciated. Thanks.

There is not a slow mode on your engine.<br />Check for air leak in fuel line and maybe replace the bulb with a OMC fuel bulb, no aftermarket stuff. OBTW, does the bulb go soft or flatten out when it stats to bog? I went through some of the same things with my 1985 XP 150.

 

[lowbud]

Re: 1985 Johnson 150 - VRO or Carb Problem?

Thanks for the come back. When I tried the portable tank I used new hose and a new OMC bulb. Still the same problem. When it bogs it does get a little soft but does not flatten out. From what I understand that is acceptable. <br /><br />I have inspected the fuel hoses and have not been able to identify any possible sources of leaks.

 

[Dhadley]

Re: 1985 Johnson 150 - VRO or Carb Problem?

If the engine looses power and when you squeeze the bulb it runs OK then you need to look at the fuel pump system. By squeezing the bulb you become the fuel pump. <br /><br />Thank goodness youre using the oil injection. Otherwise you may have stuck a piston already.

 

[lowbud]

Re: 1985 Johnson 150 - VRO or Carb Problem?

Can a 1985 VRO be rebuilt? It is the type without any wires on it. <br /><br />My service manual has nothing about rebuilding a VRO. Can I follow a more recent years instructions?

 

[Dhadley]

Re: 1985 Johnson 150 - VRO or Carb Problem?

Youll want to change it the new style pump. That will upgrade you to the OMS pump with all the warnings.<br /><br />Youll need;<br />5004559 pump<br />174710 harness<br />331122 bracket<br /><br />If you dont have the self-test horn, now would be a good time to get that too.

 

[lowbud]

Re: 1985 Johnson 150 - VRO or Carb Problem?

One step forward, maybe two back?<br /><br />I purchased a slightly used VRO pump and installed it. I also changed all the hoses. While I was not entirely convinced it was a VRO problem, the hoses were a concern. A 1985 outboard. The motor ran great on muffs in the driveway. <br /><br />Went down to the dock and pumped the primer bulb. I kept on pumping it as it was not getting entirely firm. Took off the outboard cover and could hear gas skirting and then dripping. Look over all the new hoses installed and could see no leaks. I then noticed gas coming out the bottom of the air intake manifold.<br /><br />What's going on? A stuck float? What do I need to do?<br /><br />In the numerous attempts at trouble shooting the outboard, I never noticed gas coming out the manifold. The bulb always got hard. Could I have done something when installing the VRO and new hoses?<br /><br />Could it be the electric primer?<br /><br />My other question is, the VRO pump has a four wire connection. Where or how would I determine were these get connected? My 1985 service manual had none of these wires.<br /><br />Thanks again.

 

[Dhadley]

Re: 1985 Johnson 150 - VRO or Carb Problem?

First get a manual that matches the year of whatever pump you bought. If it has the 4 wire connector youll most likely need the harness listed above.<br /><br />If your now dripping gas and you werent before (or was it and you didnt notice?) youll have to make sure of a few things.<br /><br />1- Are the hoses connected correctly in order?<br />2- Is the primer in the manual "On" position?<br />3- If needed you may have to pull the airbox cover off and see where the fuel is coming from. If its coming out of a carb throat it may well be a stuck needle.<br />4- Be very cautious of a "used" oil pump. You do realize the motor lives on the lube it supplies, right?<br /><br />Cleaning the carbs anyway is not a bad idea. That includes new kits.

 

[lowbud]

Re: 1985 Johnson 150 - VRO or Carb Problem?

I will get the manual for that VRO/electrical.<br /><br />1 - Hoses replaced one at a time. Pretty straight forward job if you take your time.<br />2 - Yes, primer in RUN position. (pointing towards its base) <br />3 - Yes, will need to take cover off. Ran out of daylight.<br />4 - I premixed oil with the gas as a precaution. <br /><br />I rebuilt the carbs a few years back and it has been running well since, until recently with the bog at WOT. Pumping the bulb always helped it run better. Would a stuck needle cause these problems? Thanks.

 

[lowbud]

Re: 1985 Johnson 150 - VRO or Carb Problem?

Just a quick update. Originally I was having trouble with bogging at high rpm. I did replace my VRO and all the fuel and oil lines recently. Then it was gas leaking, possibly from a carburator.<br /><br />Went down this past weekend to work on it and the leak is gone, or at least for now. Whether something was hanging up a needle I will never know. Took the boat out on the water and it performed well. No bogging and no fuel leaks. Just wanted to thank every one for their advice. <br /><br />While I am not 100% convinced that everything is perfect, can't do much until something fails. I am sure I will be posting soon about other issues - like the horn that is on almost all the time or why my rpms jump all around from 3500 to 6000. But I will leave that for another day.