1985 Johnson 115 Help Please!!

[waknstak]

I have a Johnson 115 that will run great for a mile or so then it acts as though it is running out of gas. I have had the carbs rebuilt, I rebuilt the fuel pump(original vro had been removed), New fuel filter, new hose connector and primer bulb, checked tank vent and pickup. It will continue to run but will not get on plane. Any ideas??

 

[tashasdaddy]

Re: 1985 Johnson 115 Help Please!!

did you remove the jets and clean them. see carb cleaning in the TOP SECRET FILE. also linc n sinc.

 

[waknstak]

Re: 1985 Johnson 115 Help Please!!

Yes the carb has been completely rebuilt by a very reputable OMC tech.

 

[waknstak]

Re: 1985 Johnson 115 Help Please!!

It will run like a scalded dog for about a mile then the problems start. If you let it sit for an hour and fire it up it will run great again for another mile.

 

[ezeke]

Re: 1985 Johnson 115 Help Please!!

It probably is running out of gas: The system needs to maintain full float bowls in order to have a source that the engine can pull fuel from. If anything slows or limits the flow of fuel into the bowls, you will have the problem.

Start by checking your fuel pickup, then the anti-siphon valve, then the primer bulb and hose. At high performance level, your engine may need 3/8" lines instead of the stock 3/16". If you have other than a full sized outboard marine fuel filter, you should consider changing it.

Also, the conventional lift pump on a 1985 115 is marginal at high performance levels.

 

[waknstak]

Re: 1985 Johnson 115 Help Please!!

I've tried two brand new, different size fuel hoses and primer balls. Removed and cleaned the tank and checked the pick up, fuel pick up was clean. Its so frustrating cause this motor starts easy and will scream for about a mile. I thought about the fuel pump possibly being inadequate as you said, but if that was the case I should just be able to pump the ball and fill the bowls and it should run fine for a while right? Where is the anti siphon valve?? Is it in the elbow coming out of fuel tank?

 

[ezeke]

Re: 1985 Johnson 115 Help Please!!

The anti-siphon valves are usually in the elbow coming out of the built-in fuel tanks. They usually consist of a spring loaded ball bearing. They collect junk and the old ones were not calibrated for ethanol.

The anti-siphon valve is Coast Guard required when any part of the fuel line system is below the level of the tank, but can be removed if the lines and engine are set higher than the tank.

 

[waknstak]

Re: 1985 Johnson 115 Help Please!!

Thanks Ezeke, I will check out the anti siphon next. Also is there a certain fuel pump that is commonly used when VRO s are removed ?? Or do most use the vro with the oil side cut off. Mine was done by a previous owner.

 

[jriegle04]

Re: 1985 Johnson 115 Help Please!!

http://www.youtube.com/watch?v=SEbW-6eOc5I this video explains the VRO better than I have seen yet.

 

[waknstak]

Re: 1985 Johnson 115 Help Please!!

I do not have a VRO pump on my motor. I have a rectangular shape pump with a triangolar shaped top. I rebuilt this pump but I am concerned if it is providing the neccessary fuel to the carbs. Is there a pre VRO pump for a 115 or larger Johnson that will work??

 

[ezeke]

Re: 1985 Johnson 115 Help Please!!

The last standard conventional lift pump in that series of 115HP recreational motors was used on the 1983 115 motors. The part number was 388268. It has been superseded by several newer pumps: 0395713,0398338,0432451,0433387,0438556.​

Part Number:0388268DescriptionUMP AY,FUEL Pack Qty:1Dimensions:3.50 x 2.25 x 2.25 (in)Weight:0.44 lbsEquivalent​

 

[Steve2603]

Re: 1985 Johnson 115 Help Please!!

Get hold of a stand alone gas tank with fresh clean gas and plumb it direct into the fuel pump. if you still have the problem and pumping the primer bulb will not clear it then you need to look at the carbs again.

I have that same pump on my 90hp and it works fine, I tried the vro pump to see if there was any improved performance and there was not.. just make sure you have the seal between the pump and engine block in place.

check here for pump replacement: http://www.marineparts.com/sierra/sierra157.aspx

 

[waknstak]

Re: 1985 Johnson 115 Help Please!!

Steve, I can check it out. I have a small tank. But if its is the carbs why would it run great at first? I could understand the type of problem coming from a clogged high speed jet but it would run that way all the time wouldn't it?

 

[ezeke]

Re: 1985 Johnson 115 Help Please!!

There should not be any difference with the 90HP motor.

It is with the mid 1980's and up 115 crossflow that the lift pumps may have difficulty in keeping up with the engine demand at WOT. The VRO and OMS pumps are more powerful, period. Put a gauge an each and see for yourself as I did.

 

[waknstak]

Re: 1985 Johnson 115 Help Please!!

If I am running on plane and it begins to act up and I back off to 1/2 throttle it doesn't help either. It still acts like its running out of gas. Like I said It sounds terrific, planes quickly and pushes my little Ranger right along for a mile or so then the problems start. Is there anything else temp Sensors, oil sensors , electrical items that could cause these symptoms. I am not getting any audible alarms by the way.

 

[jriegle04]

Re: 1985 Johnson 115 Help Please!!

do you have a yellow or black goop running down from under the flywheel? if so, that indicates a stator melting.

 

[ezeke]

Re: 1985 Johnson 115 Help Please!!

Sure, ignition coils can run fine when cool and fail when heated. You could run with an inductive timing light and check that on the water if you let your friend drive.

Some use a hair dryer on the running ignition coils to heat enough for a test. (I don't know how they know when enough heat is enough, though.)

 

[waknstak]

Re: 1985 Johnson 115 Help Please!!

thanks for the ideas, I appreciate everyones time. I will check some of these things out and see if they help. The bad part is I have to go an hour one way to run it to see if anything works.

 

[Benny1963]

Re: 1985 Johnson 115 Help Please!!

had same prob went with the newer v6 pumps .premix 3/8 line , hi flow bulb
straight to the fuel bar bypassing the quick connect, runs great
but my probs were at 5800 or so only
pushing you primer bulb in helps seems fuel related, but with timeing light when it acts up will tell ya if its breaking down when hot ,chaseing and ign prob know
good luck also my motor was v6

 

[Rangerwing]

Re: 1985 Johnson 115 Help Please!!

I have a 97 Ranger R82 Sport with a Johnson 150hp Fast Strike with this fuel starvation issue. My previous Ranger developed it just before I sold it and the current owner still has the problem. I've been combing through these forums in search of an answer. This morning I picked up my R82 from the local mechanic and he removed the anti-siphon valve completely. He said I'd be surprised to know how many boats run without one. Mine ran fantastic once I was able to get it up on plane probably due to the fuel pump, but the primer bulb would collapse and the engine would starve out. I can say the boat no longer has the starvation problems and it runs like new again. Worth every penny, but would have been better if I knew this was the problem. Everything else (compression, electrical, etc.) checked out great. Hope this helps.