Im having trouble keeping a rate on my 440 on a pull type sprayer.  I have the sprayer hooked to  986 and a 540 pto pump.  It has a return line before the valve and flowmeter.  Im looking for 12.5gpa and i have yellow aixr tips.  It seems to run low on pressure and rate. The spded seems low when i compare it to a speedometer i have on my phone.  My speed cal is 587 and im set on sp1.  do i need to have it set to sp2?  On another sprayer i have the raven holds a rate almost perfect and im not sure what im missing on this one.  Thanks for any suggestions.