Problems converting VRO to conventional lift pump

[parrisw]

I hope you guys don't mind me starting another thread on this, I'm still looking for more help.

Engine is a 1984 Johnson 115hp

I've taken the VRO pump off since I think the diaphragm had a hole in it causing it to over-fuel #4 cylinder, so I picked up a conventional pump 438556, which the local parts guy told me replaced the 433387, it looks exactly the same, so it got bolted to the block right where the VRO pump had its pulse line connected to, and it wont hardly pump any fuel, he gave me another pump to try, the remote mounted one that uses a line to connect the pulse hose, and it hardly pumps as well, so I stuck back on the old VRO pump and it pumps fuel just fine??????? So what the heck am I missing here??? I really could use some help here, boating season is on me now, and my boat wont run.

Thanks allot for any help!!

Will

 

[kenmyfam]

Re: Problems converting VRO to conventional lift pump

Look the part number up here.

http://shop2.evinrude.com/ext/index.aspx?s1=bf6ad09c53cead335fcfd8a6471c0f7f

Plug in for a 1982 version.
I used a pump on my motor from a 1982 150hp which is the same pump as the 235hp as well. The V6 motors have 2 pumps on them but one will be just fine for your motor. Some folk say this pump may not be enough for a looper but mine pumps way more than I could ever need with my motor.
Part number here is #388555

 

[parrisw]

Re: Problems converting VRO to conventional lift pump

Look the part number up here.

http://shop2.evinrude.com/ext/index.aspx?s1=bf6ad09c53cead335fcfd8a6471c0f7f

Plug in for a 1982 version.
I used a pump on my motor from a 1982 150hp which is the same pump as the 235hp as well. The V6 motors have 2 pumps on them but one will be just fine for your motor. Some folk say this pump may not be enough for a looper but mine pumps way more than I could ever need with my motor.
Part number here is #388555

Thanks again for your help, I'll give the guy that number tomorrow. Does the number I listed there mean anything?

 

[kenmyfam]

Re: Problems converting VRO to conventional lift pump

Thanks again for your help, I'll give the guy that number tomorrow. Does the number I listed there mean anything?

Having a look. Will let you know if I find anything. Is it an OEM pump or a sierra or other aftermarket ??

 

[parrisw]

Re: Problems converting VRO to conventional lift pump

Having a look. Will let you know if I find anything. Is it an OEM pump or a sierra or other aftermarket ??

Its an OEM pump, he said it replaced the 433387 which was recommended to me on here a couple months ago.

 

[tashasdaddy]

Re: Problems converting VRO to conventional lift pump

i would use one of the following. 3 line pumps, the uses the pulse line to power it. these were used on 115 and 135 motors.

Part Number: 0385784
Description: FUEL PUMP AY
Pack Qty: 1
Dimensions: 3.50 x 3.50 x 2.25 (in)
Weight: 0.44 lbs
Equivalent Parts: 0395712,0398385,0433390,0438559

the pump you are trying is for smaller motors, 25-55 hp, look at this;
http://www.iboats.com/Fuel-Pump-for...8270172--**********.385723955--view_id.174141

 

[Cricket Too]

Re: Problems converting VRO to conventional lift pump

I hope you guys don't mind me starting another thread on this, I'm still looking for more help.

Engine is a 1984 Johnson 115hp

I've taken the VRO pump off since I think the diaphragm had a hole in it causing it to over-fuel #4 cylinder, so I picked up a conventional pump 438556, which the local parts guy told me replaced the 433387, it looks exactly the same, so it got bolted to the block right where the VRO pump had its pulse line connected to, and it wont hardly pump any fuel, he gave me another pump to try, the remote mounted one that uses a line to connect the pulse hose, and it hardly pumps as well, so I stuck back on the old VRO pump and it pumps fuel just fine??????? So what the heck am I missing here??? I really could use some help here, boating season is on me now, and my boat wont run.

Thanks allot for any help!!

Will

I understand what you're trying to do, just not the reasoning for doing it.

The cylinders get their fuel/oil mix from the carbs, not the VRO, the VRO supplies all the carbs the same way, it in itself isn't gonna put any less or more fuel to any cylinder in particular, and you have 4 cylinders being supplied by 2 carbs, so if you had an issue with a cylinder being "over fueled" or running rich, then you'd have 2 cylinders having that issue if it was a carb problem, and all cylinders/carbs having the issue if it was a VRO problem, as both carbs get the same supply from the VRO. Not just one cylinder singled out on it's own.

I think that was one of the biggest misconceptions or misunderstandings that was spread around about VRO. If you are having an issue with one cylinder than it's not a VRO issue.

Not saying you shouldn't replace with a straight fuel pump and premix, if you want to go that way, but I'd think you'd still have your carb issue after that.

 

[parrisw]

Re: Problems converting VRO to conventional lift pump

I understand what you're trying to do, just not the reasoning for doing it.

The cylinders get their fuel/oil mix from the carbs, not the VRO, the VRO supplies all the carbs the same way, it in itself isn't gonna put any less or more fuel to any cylinder in particular, and you have 4 cylinders being supplied by 2 carbs, so if you had an issue with a cylinder being "over fueled" or running rich, then you'd have 2 cylinders having that issue if it was a carb problem, and all cylinders/carbs having the issue if it was a VRO problem, as both carbs get the same supply from the VRO. Not just one cylinder singled out on it's own.

I think that was one of the biggest misconceptions or misunderstandings that was spread around about VRO. If you are having an issue with one cylinder than it's not a VRO issue.

Not saying you shouldn't replace with a straight fuel pump and premix, if you want to go that way, but I'd think you'd still have your carb issue after that.

Ok maybe I'm wrong but the cylinder was getting too much fuel is #4 which is the cylinder that feeds the pulse to the fuel pump, if there were a hole in the diaphragm would it not suck fuel through the pulse line into #4 cyl? Maybe I'm way off in my thinking but if it were a carb issue wouldn't both bottom cylinders be getting too much fuel? When I crank the engine over with no plugs I get a fuel spray out of #4.

 

[parrisw]

Re: Problems converting VRO to conventional lift pump

Ok, little update here. First off I'll say sorry for wasting all of your guys time. I talked with a local marine mechanic, he said if there were a hole in the diaphragm to hook it all back up take off the pulse line, squeeze the heck out of the bulb to pressurize the fuel system, and see if any fuel comes out of the pulse connection to the VRO pump, so I did that and well, nothing comes out, so Im guessing the dang pump is fine!!!!!! So I then cranked the engine over for about 10s, and pulled all the plugs, well, the bottom 2 are wet, top 2 are dry, now I could a sworn up and down, that it was only #4 that was getting too much fuel. Hmm oh well live and learn I say, so now it seems that I have a problem in the bottom carb? possible needle and seat not sealing? Good thing I got 2 carb kits last time I ordered parts, so I guess I'm doing carb rebuilds now. Anything to look out for?

Many thanks

Will