On a flow-mate pump what kind of oil is in it

Chainsaw oil pumps are fairly simple affairs, to increase oil flow you obviously cannot increase the engine speed, so you increase the throw of the pump shaft, so the pump shaft not only rotates, it moves back and forth ( the throw ) so the back of the pump shaft is cut off at an angle, the adjuster screw sits on the back of the shaft, so now when it rotates it moves in and out due to this angle, so the close the screw is to the centre of the shaft the lesser the throw, the further out the bigger the throw, so unscrewing the adjuster ( anti clockwise ) increases the flow, and visa versa.

Very low or no oil pressure reading does not necessarily mean the oil pump is not working and if you replaced the oil pump because of low oil pressure does not mean the original pump had necessarily failed. It may have but it may not have. Oil pressure is not created by the oil pump but by the resistance to oil flow. If you have very low resistance to flow you will get very low oil pressure no matter how well the oil pump is pumping. If you have a very worn engine, especially the bottom end main bearings and conrod bearings, tolerances increase very significantly, there is little resistance to flow and you will achieve very low oil pressure and metal parts will touch. Oil flow to the upper part of the engine may also suffer. If your engine is gummed up with oil sludge due to too few oil changes some oil passages may be blocked as well.

Since you already replaced the heads, check for engine block cracks or uneven mating surfaces with the heads.

The check ball in the oil pump is the problem. It either gets dirt on it, or just doesn't mate up properly with its seat. This allows the engine to "sump", meaning because the crankcase is lower than the oil tank, the oul flows from the tank into the crankcases. I doubt there is a drain plug at the bottom of your engine cases, so the only way to get the oil out of the crankcase is to place a pan under the vent and run the bike. Keep an eye on the oil level in the tank, but don't add a lot if it gets low. Some oil will be circulated back the tank by the oil pump. The simple fix to this problem is to place a clamp on the oil feed line to the pump if you're gonna let the bike sit for awhile. This will not allow the oil to flow from the tank. Replacing the pump again, or reseating the ball may or may not solve your problem. My '91 bagger has the same problem. I just clamp the feed line when I store it for the winter and have no sumping problem when I fire it up in the spring. just remember to remove the clamp before starting the bike!

Oil Pump Replacement REMOVAL

1. Remove the oil pan.
2. Remove the oil pump from rear main bearing cap.

INSTALLATION

1. Install oil pump. During installation slowly rotate pump body to ensure driveshaft-to-pump rotor shaft engagement.
2. Hold the oil pump base flush against mating surface on No.5 main bearing cap. Finger tighten pump attaching bolts. Tighten attaching bolts to 41 Nm (30 ft. lbs.) torque.
3. Install the oil pan
4. This procedure is for the 3.9L, 5.2L and 5.9L

Installation
Install crankshaft sprocket on crankshaft.
Make sure mating marks on crankshaft sprocket face front of engine.

Position crankshaft so that No. 1 piston is at TDC and crankshaft key is at 12 o'clock.

Install slack side timing chain guide and timing chain tension guide.

Install timing chain on crankshaft sprocket.
Set timing chain by aligning its mating mark with that on the crankshaft sprocket.
Make sure sprocket's mating mark faces engine front.

Install camshaft sprockets.
Set timing chain by aligning mating marks with those of camshaft sprockets.

Install camshaft sprocket bolts to correct torque.
Apply new engine oil to bolt threads and seat surface.

Install chain tensioner.
Before installing chain tensioner, insert a suitable pin into pin hole of chain tensioner.
After installing chain tensioner, remove the pin.
Install timing chain guide.

Install O-rings to cylinder block.

Before installing front cover, remove all traces of RTV silicone sealant from mating surface using a scraper.
Also remove traces of RTV silicone sealant from mating surface of cylinder block.

Apply a continuous bead of Genuine RTV Silicone Sealant or equivalent to mating surface of front cover. Refer to RECOMMENDED CHEMICAL PRODUCTS AND SEALANTS .
Check alignment of mating marks on chain and crankshaft sprocket.
Align oil drive spacer with oil pump.
Place timing chain to the side of chain guide. This prevents the chain from making contact with water seal area of front cover.

Install front cover.

Make sure two O-rings are present.

Be careful not to damage oil seal when installing front cover.
Install cylinder head bolts at engine front side as shown in Fig. 55.
Tightening procedure:
Tighten bolts (1 - 4): 6.3-8.3 N.m (0.64-0.85 kg.m, 55.8-73.5 in.lb).

Install oil pump drive spacer.
Install water pump and water pump pulley. Refer to REMOVAL AND INSTALLATION .
Install idler pulley and bracket.

Install RH engine mounting bracket

Install RH engine mounting.
Install oil pan. Refer to INSTALLATION.
Install crankshaft pulley.
Remove ring gear stopper.
Install starter motor.
Install cylinder head front cover.
Apply RTV silicone sealant to cylinder head front cover.
Use Genuine RTV Silicone Sealant or equivalent. Refer to RECOMMENDED CHEMICAL PRODUCTS AND SEALANTS .

Install Camshaft Position Sensor (PHASE).

Before installing rocker cover, apply a bead of Genuine RTV Silicone Sealant or equivalent, to mating surface of cylinder head as shown in .

Install rocker cover gasket into rocker cover.
Install rocker cover and tighten in numerical order as shown in
Install spark plugs.
Install ignition coils.
Install front exhaust tube.
Install front/right-side splash undercover.
Install front RH wheel.
Install drive belts.
Adjusting drive belt deflection..

not so fast,, yes thick hydraulic oil can cause slow hydraulics and if the hydraulics speed up when warm then this may be your problem. if they dont then you need to look at possible problems with the pump, the spool, or linkage to spool. remember that speed is flow, a pump can have good pressure but lousy flow. also there should be some kind of pressure relief valve in system if this stuck open then it will let oil go back to tank causing your problem. there is no quick answer to your problem but there are a lot of possibilities. need to do some diagnosing!

Mate.It pretty much flows the number.IE 500 holley is 500cfm.48,s are 480.Thats a big bit of gear for an rx7.Just make sure the metering pump for the oil injection into the carbs are upgraded,otherwise the motor will cook the apex seals every week.It would not hurt to up the oil pressure by 2 lb if you are going to rev the motor over 7400rpm.Are you putting side draught or down draught.Hope you go well!

Did you prime the new pump properly before installing?

You will probably have to clean the oil orifice on the bar, if this does not do it you will probably have to clean and maybe rebuild the oil pump.