1993 Johnson 115, running issues at over 15mph.

[colinwalsh]

Hey everyone I have a nice johnson 115 2 stroke that is having issues when I want to go faster than 15 mph. when I try to hit the throttle my motor wants to cut out and bog down. However If I or somene else goes back to the fuel tank and pumps the ball I am able to pouch the throttle faster and the motor doesn't want to choke out. the ball on the fuel line is newish (less than 2 years old) and the fuel tank is the same age. I also have the manual for this outboard. Thank you for any advice or suggestions with addressing this issue.

 

[Will Bark]

When my 150 Johnson did that it was time to replace the fuel pumps; my motor was changed from VRO to just premix using dual fuel pumps. Good luck

 

[hardwater fisherman]

Maybe the fuel pump?

 

[rothfm]

I have the same motor/year...I premix also thru the same VRO unit. More than likely your pump. I keep several as spares and it took 2 swaps to get a good one in there. Each exhibited different symptoms (one did as your description, one had a weird roughness when decelerating) but yes, its the pump. I havent seen on the v-4 how to omit the std dual chamber VRO unit...But there are alot of them out there, and you can rebuild the fuel side, and just leave the oil side unused/connector unplugged.

 

[racerone]

Any earlier than 84 V-4 fuel pump can be fitted.----Also any pump from the 88 hp models can be fitted.----The place to mount those pumps is already there on the intake manifold.---Bit of hose work required as well.

 

[emdsapmgr]

If the engine runs fine at WOT as long as someone constantly primes the fuel hose bulb-likely the fuel pump is weak and is in need to replacement. Instead of using the cheaper pump off an 88, why not get one from an earlier 125 1972 model. It uses the single pulse hose line, just like the VRO does on your engine. Sold under current part number: 438559.

 

[colinwalsh]

awesome thank you so much for the quick responses guys! where would you recommend picking up a fuel pump? and is the installation easy? I am handy but not a mechanic by any means. Thank you again. fish on!

 

[Bosunsmate]

You can pick one up on this site.
Easy job, just post any questions after it arrives

 

[rothfm]

If the engine runs fine at WOT as long as someone constantly primes the fuel hose bulb-likely the fuel pump is weak and is in need to replacement. Instead of using the cheaper pump off an 88, why not get one from an earlier 125 1972 model. It uses the single pulse hose line, just like the VRO does on your engine. Sold under current part number: 438559.

EMDSAPMGR: I'm getting a couple of these fuel pumps (438559) do you know if there is a good spot to mount them? Would it be somewhere in vacinity of existing VRO(to be removed).

I like this idea...I've been playing around with the VRO's for some time. This seems cheap and easy, and I can carry spares and swap on the water if needed.

Thanks

Mark

 

[Will Bark]

Will the 115 need more than one pump? I know my 150 has 2 where do they switch over to need 2?

 

[rothfm]

Dont quote me, I believe the v-6's have both, under-only uses one.

I see there is a hole in the back, and it comes with that little gasket. I'm thinking it has to mount over the Ccase port. But it says "external Pulse" and has a nipple for it-I didnt think it would have to mount directly over that Ccase port with a gasket.

Just a bit confused if it has to mount that way. Or just locate it anywere and hose it to the Ccase port like it currently is setup. If So, what is the gasket for?

 

[emdsapmgr]

Your V4 will take one pump. (the V6 engines took two.) You can look at a 1983 V4 115 hp engine at the factory parts list site: epc.brp.com If you look through these exploded parts lists, you will see how to connect it up. (that was the last year before the VRP pumps came out.)

 

[racerone]

Gasket is used when pump is mounted directly to the intake manifold and the pulse port.---There is a place to mount it on the 93 model V-4.------If you install a pump with 3 hoses to it you do not need the gasket.

 

[V153]

I reckon if you plumb it right you can mount it anywhere ya like. But why not use the mounting position on the intake?

Let you in on a lil secret. Though it's prescribed for smaller motors. #438556 works just fine.

 

[racerone]

Agreed the 438556 from the 88 hp model fits right on the intake manifold.---And it will pump plenty of fuel for the 115 , both models use the same block.

 

[colinwalsh]

Agreed the 438556 from the 88 hp model fits right on the intake manifold.---And it will pump plenty of fuel for the 115 , both models use the same block.

Just to make sure I am taking out and replacing my huge ugly VRO with this pump correct? I looked it up online and it said it was only good to 55hp. Any other info would be great as I am about to do the work this coming week. Thank you.

 

[racerone]

Not sure why you are doubting good information.--Just install that 438556 on the place meant for it !!!!!!!!!!

 

[colinwalsh]

Not sure why you are doubting good information.--Just install that 438556 on the place meant for it !!!!!!!!!!

Im not doubting the information at all, I am very stoked on all the positive responses. I am just wondering if i remove the huge VRO and replace it with this part number as recommended. thank you, I'm new to working on motors and just want to make sure I am doing it correctly. thanks again. fish on.

 

[emdsapmgr]

If you use the pulse from the hose that went to the old VRO, just make sure it adapts to the new pump, and that the pulse line does not kink, if you have to bend it to fit. Bulk fuel hose will kink if bent into a tight radius. So be careful with the install.

 

[Fed]

I'd be looking for a blocked jet, there should be enough fuel in full bowls to punch up to max rpm or at least well over 15 mph before you run out.