1994 V4 115 Johnson Bubble back fuel consupmtion

[Fishjustin87]

I have a 94 115 bibbleback that I converted to a conventional diaphragm fuel pump. I bypassed the VRO. Through this forum I was told to se a 1983 140 fuel pump. Works great and runs strong. It shutters a little in gear at low RPM but seems to idle and run great at WOT. What is normal fuel consumption for a motor like this. I seem to be burning about 6 gallons an hour between Wot and putting around pulling pots. Is this normal or do I need to lean out the carbs a bit? If so what would be recommended? Both carbs have 2 screws on the face of them. Cant really use the manual for this as I converted away from the Vro. Any input would be much appreciated. Thanks

 

[racerone]

Removing the VRO would make no difference as far as following the manual !-----I do not see any mixture adjusting screws on these carburetors.------But post a picture of what you think are adjusting screws.

 

[Bosunsmate]

If you run at WOT you will use a lot more fuel than if you ran at about 2/3 to 3/4 throttle.

 

[Fishjustin87]

Racerone, I believe what I was mistaken is an idle orifice. ORIFICE, IDLE, #38C. #7 on the carb illustrated parts catalog. Looks like one on both carbs. What are their function?

 

[flyingscott]

They are low speed air orifices they affect the low speed air/fuel mix. Those motors are just thirsty beasts they always were and will be. 6 gallons per hr is not bad the rule of thumb is at WOT you will burn around 11.5 gallons pr hr.

 

[jimmbo]

Racerone, I believe what I was mistaken is an idle orifice. ORIFICE, IDLE, #38C. #7 on the carb illustrated parts catalog. Looks like one on both carbs. What are their function?

o


without knowing which/whose parts catalog you are referring to...

on a carb, an Orifice is used to restrict either fuel flow, or as an calibrated air-bleed, both of which are used to calibrate the carbs fuel delivery curve

 

[Fishjustin87]

# using marineengine.com. model number of motor is J115TLARC

 

[Fishjustin87]

All those stars are supposed to say Marine Engine Website.

 

[havoc_squad]

If iBoats carries what you are asking to buy/get, it is against forum rules to list competitor names in forum posts/topics.

That is why your posts are being edited by the admins.

If in doubt, PM an Admin.

 

[havoc_squad]

Edit, accidental double post in editing.

 

[Fishjustin87]

This is not to purchase. Only for reference so he knows what screws I am talking about. Pretty sure diagram referenced is the omc one