I just purchased this compressor Hitachi 1 HP 4 Gallon 135 PSI Electric Air Compressor. The oil that it came with, is it enough or the rigth amount.

That is exactly what you will get, There are no repair parts. buy oil lubed compressor. be aware that the comp may not deliver enough air at high pressure for task.

MCGRAW 21 gallon 175 PSI Oil-Free Vertical Air Compressor
CENTRAL PNEUMATIC 29 gallon 2 HP 150 PSI Cast Iron Vertical Air Compressor

The model number is not enough info but assuming it's a run of the mill, Home Depot or Craftsman type electric air compressor, you need to buy compressor pump oil at Wal Mart or an auto parts store. Please don't use Automotive motor oil because that's not going to withstand the heat of your compressor pump and you'll be buying a new compressor because of it. If your compressor has a gasoline, 4 Hp. motor, it needs Mobil 1 synthetic and change it after every 30 hours of operation.

Looks like two covers needs removing. Kobalt Parts U12HCCL 0320358 Air Compressor

If it's new I would return it. However that model number 16638 is for a Huffy Bicycle.

do you have enough amprage going to the compressor

my ace air compressor which is 26 gallon 5 hp will not get over 60psi what is wrong with it please?

You can get the manual for model 41214 from my dropbox area:

http://dl.dropbox.com/u/54567653/husky_aircompressor_model_41214.pdf

BTW, if you find this manual helpful consider installing dropbox using this link (full disclosure -- I do get about 0.2 GB freespace from dropbox if you install using this link):
http://db.tt/vQycqXIW

Thanks,K

Yes,but if the max is 125 you don't want to increase it above 110 and set off the pressure relief valve.

Here are the specs on your compressor:
Electric Single Stage Air Compressor, Motor Running Power 5.0 HP, Free Air Flow @ Maximum Pressure 16.1 CFM, Free Air Flow @ 90 psi 18.0 CFM, Maximum Pressure 135 PSI, Phase Single, Voltage Rating 230 Volts, Current Rating 21.5 Amps, Tank Capacity 60 Gallons, Tank Type Vertical, Height 71 Inches, Length 20 Inches, Width 30 Inches, NPT Outlet (F) 1/2 Inch, 60 Hz
Good luck with your new comressor.

I think you'll have to look at your specs on your nail guns and see what the demand is . Whether measured in cfpm or psi, your compressor will tell you the max output of each of those. Then you divide the maximum sustained output of the compressor,, lets say it is 60 psi. Let's say the guns require 10 psi, 60 divided by 10 is 6 = 6 nail guns. This is completely hypothetical as I have no idea what your nail guns require, only you know what kind of guns you have.If you need to run more guns than the compressor can push air for, you'll have to invest in another compressor, maybe even one larger to handle the guns running wide open consistent nailing. Nothing a drywaller hates more is than for all the cursed clip nails not being drove in all the way, lol, and that's what will happen with insufficient air supply.
Matt