94 Johnson 225 Fuel Starvation WOT

[ecu1984]

Compression is good, motor cranks, idles smooth and runs out strong at all ranges.
RPMs max out around 5800
Top speed is 44mph , Kencraft Challenger 215 CC
Run all day at 38mph perfectly but push the throttle that last 1/2 inch and hit 40 mph and starts surging
I had my son take the wheel and hold it down while surging at 40mph and i pumped the bulb and it smooted right out.
then a minute later surging at WOT until I hit teh bulb a few times and runs great again.
In a nutshell, starving for fuel at WOT but ok with a very slight decrease in throttle.
Bulb is not flat but soft and I can feel the fuel go thru it when i squeeze it.
Bulb is very old and will get replaced as a cheap maybe fix
I have a fuel/water separator thats fairly new and no leaks
Fuel line is 3/8 and new from the water separator to the fuel pump with an inline filter (new).
All clamps tight and no visable leaks.
VRO is disconnected and premix, though still using the original VRO fuel pump
Link and sync is perfect.......
Bulb?
Fuel pump?
I dont think its a restriction due to running strong at 38mph all day, just drops off at that last knudge of throttle.
Pumping bulb cures it
Thanks

 

[racerone]

It is not the bulb.----Test run with a portable fuel tank and hose.

 

[ecu1984]

yep, probably not but wont hurt to upgrade it. The current one is probably 10 years old.
I feels like the bowl runs out of fuel at that last little bit of throttle and then when i pump the bulb, the bowl level catches up.
I am thinking I need to take the carbs off one or two at a time and drop the bowls, set the floats and pull out, clean and re-seat the jets. Wishful thinking it's something simple. If the symptoms go away on a portable tank then the issue is behind the motor and probably lies from my tank to the water separator? If the issue persist, then I assume its fuel pump or carbs?

 

[Faztbullet]

Replace VRO...

 

[dingbat]

Bulb does nothing but prime the fuel pump on first start.

Separate tank eliminates the fuel system (anti siphon valve, fuel line and separator leaks) from contention.

My money is on the fuel pump if your still running the OE pump.

 

[ecu1984]

Thanks for the replies, the fuel pump on it is the original VRO pump.
Do they make one that is fuel only to replace it for those that have disconnected the oil side and premix?
Part number? I would like to replace it even if not the issue, just for a preventative measure and future reliablity.
1994 225hp Johnson
Thank you
Rick

 

[dingbat]

Thanks for the replies, the fuel pump on it is the original VRO pump.
Do they make one that is fuel only to replace it for those that have disconnected the oil side and premix?
Part number? I would like to replace it even if not the issue, just for a preventative measure and future reliablity.
1994 225hp Johnson
Thank you
Rick

Out of interest....why did you disable the oil side to begin with?

5007422 VRO conversation pump

5007420 VRO pump

 

[ecu1984]

Out of interest....why did you disable the oil side to begin with?

5007422 VRO conversation pump

5007420 VRO pump

It was done by previous owner. I keep waiting for the darn thing to blow up so I can upgrade to a 4stroke but it was rebuild a few years ago and runs like a new motor, except for this new fuel wot bug

 

[dingbat]

I keep waiting for the darn thing to blow up so I can upgrade to a 4stroke but it was rebuild a few years ago and runs like a new motor, except for this new fuel wot bug

Same here....when all was said and done, I'm upside down with the rebuild after 4 seasons.

Now have to decide if I bite the bullet and repower again (4 stroke) or let three to five footice take command.

 

[ecu1984]

I just looked at the fuel conversion pump 5007422 price.....almost $500
I also see an aftermarket one with good reviews for less than $200.......looks just like it.....thoughts?
Also I see an OEM rebuild kit for my VRO "fuel side only" for a couple hundred bucks........is this just as feasible?

 

[ecu1984]

I just ordered the two pump system on one bracket from MasterTech. They have good reviews and I want a newer pump regardless if it fixes my issue or not. Hopefully it will. I will also buy the rebuild pump for the original VRO pump I take off and have a spare. Stay tuned

 

[ecu1984]

New non-VRO conversion fuel pump has her screamimg. Fixed