038AV chainsaw. The drive to the oil pump is a well worn plastic gear with pump and disintegrated plastic drive gear. Where can I get a diagram of this drive to know what I require to order ?

run it with the bar off and see if it pumps oil. I have drained oil tank and cleaned with gas(no run) then replaced with lite oil , run no chain and got them going ,or then gingerly run wire into oil hole and got them going, otherwise its tear apart time. If oil does come out, then clean your bar and your cover and use bar chain oil.

You probably will find the driven gear on the oil pump bad. There are plastic and gets damaged fairly easily when trash get into pump drive area.

Install worm gear, then oil pump then washer then bearing and clutch housing and clutch.

Checlk the oil worm gear is driving the pump. If this isnt the problem then try the following:-

The type of oil pump fitted to these models is prone to getting blocked.
Remove the oil pump. The gear on top should turn freely, give the pump a clean and clean the oil pipe to the tank by removing the oil cap and blowing through with an air line. If the oil in the tank contains alot of dirt, empty/clean and replace. The filter on the oil is an open plastic cage type and often will draw large sawdust particles through it. Easily rectified tho.

It is a fairly simple oil pump system, the spring gear on the crank will fit on either way, however the spacing of the coils is is critical, there is a small plastic tool to do this, i think you said you had this tool, it has to be an issue with the pump, the gear not only turns but has a throw, the amount of throw denotes the amount of oil delivered, a small steel pin in the side of the pump body works in a cut a way in the pump shaft, has the pin fallen out? just cant think what else you can do as you seem to have done everthing.

If the filter is intact, then the dirt was in the line to begin with. Disconnect the inlet line at the pump and blow out the line with compressed air (from the tank side). You might clean the oil tank while you are at it. The blow-out is unnecessary if replacing the above parts. Put some oil into the new pump to prime it. Don't try to fix the damaged plastic gear.

hi

first check the oil filter from the oil tank,the oil hose,remove the oil pump and check it(especially the plastic gear inside,if it worn is because of the bearings from crankcase).Clean the holes where oil goes.

bye savumihai71

when you say that you changed the gear,was that the plastic one?check the other gear that is on the pump itself.make sure that it isn't worn.then make sure it spins freely.if it doesn't that will be you problem.cleaning them has never worked for me.........just replace it and the plastic gear.with both being new you should have no problems with oiling.the little pump gear gets scored up inside and they stop spinnig fast enough to work properly.hope this helps let me know if you have any questions

my best guess is that your oil pump has gone bad.