1986 Johnson 40 HP

[Briand3096]

I just got a 16' Lowe Super V with a Johnson 40HP VRO. The motor had no fuel flowing so it was a no start. I removed the VRO pump and replaced it with the regular one. Now the motor runs but only with the choke lever up. It will fun forever but if you lower choke it stalls out. I used all new OMC parts and new fuel lines. I removed the carbs and cleaned them and I still had the same problem. After reading some post on here. I think one of two things # I did not clean the high needle and may need a tool to remove it. or #2 Possible reed valves?? Also do I need to remove the metal caps on the top of the carbs to clean that area?
Thanks, Brian

 

[bktheking]

Re: 1986 Johnson 40 HP

You replaced the pump with a regular fuel pump correct? Please tell me you are premixing your gas? Did you cap off the tube where the vro connection went into the motor??? That would cause a vac leak if i'm not mistaken.

 

[Briand3096]

Re: 1986 Johnson 40 HP

Yes I mixed the oil in the fuel and capped off the vac line. The carbs were very clean. And I removed the small brass low speed jet but I was inable to remove the High speed one ( no tool on hand ) Carb cleaner seem to flow fine past all points no fuel overflow or leaks.

 

[bktheking]

Re: 1986 Johnson 40 HP

Ok so lets figure this out. If the reeds were gone it wouldn't start. As far as the metal plugs on the carbs, for a true cleaning they should be removed but i've gotten away without punching them out. You say choke lever up, as in will only run on choke but when the choke is opened it dies??? Did you buy this boat and it ran fine or is this a new motor to you?

 

[Daviet]

Re: 1986 Johnson 40 HP

Do you have to choke it to run at all speeds? Will it idle but stall when opening the throttle with the choke off?

 

[Briand3096]

Re: 1986 Johnson 40 HP

Yes choke to run and wont idle. I have not had it in the water yet. This is a new to me motor. The last owner said it needed a fuel pump. Made sense no start after new pump runs now but wont idle.

 

[Briand3096]

Re: 1986 Johnson 40 HP

New to me. Last owner said needed fuel pump.

 

[bktheking]

Re: 1986 Johnson 40 HP

These have an idle orifice, did you remove and clean it and the passage behind it?

 

[Briand3096]

Re: 1986 Johnson 40 HP

I was able to remove and clean one on each carb but not the other. I gues I need a tool to remove it. I thought it was like other carbs with some kind of a needle inside. But the only thing I found like that was the one that works the float. I removed all I could and sprayed it out with carb cleaner and then air and put back on and it ran the same. I did not soak it or run wire through anything. The carbs were very clean inside.

 

[bktheking]

Re: 1986 Johnson 40 HP

ok, 2 quick things. Spraying with carb cleaner does not clean a carb and two, the shiny metal inside the carb is all you can see, you cannot see in the idle circuit or the passages. I suspect that there is an issue with the carbs still. These are float carbs with a needle and seat not a slide type carb with multiple needles. The main jet sounds plugged, it runs with choke on cause it is getting a bit of fuel, when you open the choke fuel flow is not proper and can't be satified with the added air.

 

[Briand3096]

Re: 1986 Johnson 40 HP

Thanks I will buy the tool and rebuild kits and start with that. Can I buy cleaner at a Auto parts store to soak it in??

 

[tashasdaddy]

Re: 1986 Johnson 40 HP

cleaner at auto parts store yes. be sure to blow out both tubes in the center of the carb. the small on on the inside, supplies the low speed jets. also change all fuel lines.
read ethanol and carb cleaning. http://forums.iboats.com/showthread.php?t=299680

 

[Briand3096]

Re: 1986 Johnson 40 HP

Ok today I took the carbs off again. I ran small strans of wire through every hole and was able to see it on the other end I used a small hose and was able to blow air through everything. I did notice that on one carb the outside tube that goes around the center pick up tube is cracked on one side. It is the one that has the small holes going up the sides. Any other ideas? Also I still can't see behind the lead shot of the metal cap. The small holes on the inside are clear when I put the paper clip through them ( two in each carb )

 

[bktheking]

Re: 1986 Johnson 40 HP

Soak them in industrial carb cleaner. But before you do, what is this tube you are referencing?

 

[Briand3096]

Re: 1986 Johnson 40 HP

Not sure of the name and its not shown anywere in the parts list. When I remove the bowl there is two brass tube in the center its th outside tube that's cracked.

 

[bktheking]

Re: 1986 Johnson 40 HP

Wrap tape around it , put the hose back on and try it.

 

[Daviet]

Re: 1986 Johnson 40 HP

Maybe slide a small piece of ruber tubing or shrink tube onto the tube. The gas will melt the stickey off of the tape and might cause more problems. Just thinkin.

 

[Briand3096]

Re: 1986 Johnson 40 HP

I don't think I want to tape or shrink wrap anything on the inside of the bowl. I think that would be more problems. Thanks for the ideas guys.