View Full Version : 4240 fuel screw
blackcoal
12-11-2013, 11:09 PM
Have an old 4240 looking it turn it up a bit and maybe mess with the timing a bit and play around with the hp on the dyno. Does anyone know where the fuel screw is at on the RossaMaster Pumps that are on the front gear case?
Thanks
Jim Fulmer
12-11-2013, 11:50 PM
I wonder if it is the same as a 4450, I turned one up earlier this year, about 1/2 a turn on the fuel screw, checked the AFC for leaks and gave the low boost screw a 1/2 turn up for more fuel on the bottom. Timing is high on these, like 24-26 so I left that alone!
Jim
blackcoal
12-12-2013, 09:34 AM
a 4240 has a rotatory pump and no afc
Fox_91
12-12-2013, 02:02 PM
roosamaster and making more power? have fun. ill get a pic tomrrow at work of the grenaded engine haha.
Feed Bunk
12-12-2013, 04:02 PM
As much fuel at those burn, are you sure you want more?
blackcoal
12-12-2013, 04:38 PM
Don't farm with it, I just want to play around with timing and pump settings and see if it makes a difference. Have access to a dyno anyways.
Feed bunk or fox you know where the screw is? Pics would be great
DodgeDude55
12-13-2013, 11:23 PM
Does it have a power shift trans in it? The one we have that I turned up a bit lasted about 2 years n the trans was toast
blackcoal
12-14-2013, 11:39 AM
Does it have a power shift trans in it? The one we have that I turned up a bit lasted about 2 years n the trans was toast
no it has the quad range which can handle quite a bit of power.
so where is the screw? do you have a pic
CTDYoungGun
12-14-2013, 02:09 PM
The torque screw is on the back of the pump above the h&r. Should be an 1/8" hex with a 7/16" lock nut (probaby has a plastic tamper proof cover on it). Back it out to allow full fuel at rated rpm, but no backup fuel. To increase the fuel setting, you have to pull the top cover, throttle lever, governor stud and spring, then make the adjustment through an access hole in the housing. If it's a dm2, you only turn up one screw, if it's a dm4 you have to turn up both screws on both leaf springs and they have to be done perfectly equal so you don't throw it out of the eccentricity spec.
blackcoal
12-18-2013, 10:54 AM
The torque screw is on the back of the pump above the h&r. Should be an 1/8" hex with a 7/16" lock nut (probaby has a plastic tamper proof cover on it). Back it out to allow full fuel at rated rpm, but no backup fuel. To increase the fuel setting, you have to pull the top cover, throttle lever, governor stud and spring, then make the adjustment through an access hole in the housing. If it's a dm2, you only turn up one screw, if it's a dm4 you have to turn up both screws on both leaf springs and they have to be done perfectly equal so you don't throw it out of the eccentricity spec.
Thank you very much Seth! Do you know how far I can go before it will want to run away?
CTDYoungGun
12-18-2013, 11:26 AM
It won't ever try to run away, but a 1/4 turn on the leaf spring screw will be roughly a 10% increase in fuel delivery
Fox_91
12-23-2013, 11:46 AM
yeah, what he said.
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