021/MS210 023/MS230 025/MS250 Oil Pump Repair

D'Animal · 10-14-08, 10:09 PM

First you have to remove the cutch.

http://forum.ih8mud.com/workshops-to...chain-saw.html

Then you get into the guts of the oiler system.

D'Animal · 10-14-08, 10:20 PM

You first need to make sure the oil pick up screen is clear.

The bottom picture show were the oil should be coming out above the bar studs. You will not have a metal plate on the models listed above.

D'Animal · 10-17-08, 06:24 AM

If the strainer screen is open but the oiler is still not pumping, it's time to deaper.

Remove the drive sprocket and clutch as outlined here.

http://forum.ih8mud.com/workshops-to...chain-saw.html

nortryder · 10-26-08, 03:49 AM

Does that wire clip attach to anything on the end away from the crankshaft? Mine seems to spin freely in the housing and it looks like it should butt up against something.
Mike

D'Animal · 10-26-08, 08:02 AM

The oiler drive gear is behind the clutch assy. You will notice a groove or slot in the back of the drive sprocket drum. The wire clip of the oiler fits into this. The oil pump only turns when the sprocket is turning.

If the tip is broke off or worn off, the sprocket will not engage the oiler drive gear. This is the designed weak link of the system.

The wire clip should be snug on the polymer gear. it should not be loose. Check the gear and make sure it does not have a flat spot on it.

The gear should truning freely on the crankshaft. It is actually turnin the oil pump. The oil pump is located between the crankshaft and the bar studs.

D'Animal · 10-26-08, 09:36 AM

The next step is to reach in and turn the actual oil pump. make sure it turns freely. it is located between the crankshaft and the bar studs.

I have removed the engine from this one to better show you the detail.

D'Animal · 10-26-08, 09:43 AM

If your engine housing looks like this. You need an engine housing. Not feasible for you to pay a dealership to repair. Buy a saw. If you buy the engine housing and you do the work, it can be repaired feasibly.

What happened is someone put the drive sprocket on and did not line up the oiler drive gear wire with the slot in the drive sprocket drum. The drive sprocket held the wire down and ground up the engine housing. It destoyed the engine housing as well as the oil pump. The Gold color that is below adn to the right of the cranshaft ois the bottom of the oil pump that is cut in half.

D'Animal · 10-26-08, 10:13 AM

Next you will have to remove some of the screws holding the black handle bar on. The front right annular buffer (Rubber mount) and the top right one. Move the handle a little sideways and you will see the connector for the oil pump. I remove the handle bar assy on this saw so you have a clear detailed picture.

D'Animal · 10-26-08, 10:16 AM

A T-27 wrench is needed to remove the plastic elbow. The ealier saws used black polymer and the newer
ones use white. Remove the connector and make sure it is not plugged with saw dust. Fine saw dust can get by the strainer screen and it will collect here. The earlier saws had a screen between the connector and the oil pump. Newer ones do not.

stihler · 03-08-09, 01:30 PM

This is a great posting. I have a Stihl 025 saw with an oiler problem. Pulled off the clutch and found that the plastic oil gear and clip were worn. I replaced both and reassembled the saw but its still not feeding oil to the chain. It seems to spit oil out from an opening in the plastic case behind/next to the muffler. Is this some kind of vent? What would cause chain oil to come out of this hole? How do you clean the oil paths inside the plastic case? How do you clean the oil screen? Desperate for help...

D'Animal · 03-08-09, 10:03 PM

The set screw came out.

There is a part number for it but you can also get one at a hardware store.

stihler · 03-09-09, 04:24 PM

I just checked my saw. I dont see any threads in the hole. My saw is about 11 years old. Was something different done on the older saws? What is the purpose of the hole anyway? And how do you clean the oil passages in the plastic case?

D'Animal · 03-09-09, 04:43 PM

There are no threads. You will make threads when you install the set screw.

It was a passage that is made during manufacturing from the oil pump to the discharge hole. At the factory the hole was plugged with a plug that was harmonically heat sealed. Very seldom do they come out. In 28 years I have seen three come out.

stihler · 03-10-09, 05:09 PM

Will plugging the hole solve the problem of not getting oil to the chain?

D'Animal · 03-10-09, 05:55 PM

Yes

I will post some pics up.

stihler · 03-11-09, 05:00 PM

I'm sorry but I'm a little new at the chainsaw repair thing so I hope I'm not getting annoying. I am confused. If I plug the hole in the case do i still need to dissassemble the saw to do something to the pump. If I do I have another rookie question...How do i get to the pump? I had the saw in pieces to change the oiler gear (I tore into it before I found your posting) and I didn't see the pump. When I get to the pump you mention grooves on the piston. Do I want to see the grooves or is that an indication of a problem? If its a problem is it worth just replacing the entire pump or are they pretty expensive?

D'Animal · 03-11-09, 06:37 PM

The oil pump is pictured in post #6 and post #7 in this thread.

stihler · 03-12-09, 05:01 PM

Then what is shown in 16/17?

D'Animal · 03-12-09, 05:17 PM

I posted the pictures in the wrong thread. Those are for a MS440/MS460 oil pump.

Quote:

Originally Posted by stihler

Then what is shown in 16/17?

stihler · 03-12-09, 05:28 PM

So all you think I need to do is plug the hole in the case?

D'Animal · 03-12-09, 09:11 PM

Yes

The Part # is 9134 381 1230.

Sorry for the delay.

stihler · 03-13-09, 03:03 PM

Thanks for your help! I'll give it a try.

Smiddyt · 03-17-09, 08:24 AM

D'Animal,

I was looking on google and you seem to be the Chainsaw expert. There is a little u shaped spring that connects the kill swith/ choke that I cant get back in. Is there some trick to replacing this?

D'Animal · 03-17-09, 08:48 AM

The wire or the flat strap that the ground wire connects too?

standfas · 10-28-09, 03:24 PM

Sorry to be dragging up such an old thread...However, I still got no oil after doing this things.

The polymer gear looks good and when turned by hand the gear on the oil pump turns. I blew out the tube from the tank to the elbow and blew out the elbow itself.

The only thing I can see that may be causing my problem is the drive sprocket. When I reassemble everything, the drive sprocket has a fairly sloppy fit. Sloppy enough that it doesn't seem likely the little coat hanger wire thing that wraps around the polymer gear would stay in the notch on the sprocket.

My question is...How snug should the fit be for the sprocket?

standfas · 10-28-09, 03:35 PM

I think I may have answered my own question. I'm missing the needle cage. It wasn't there when I disassembled.

D'Animal · 10-28-09, 03:35 PM

The end of the "wire" on the oiler drive gear may be worn down.

When you slide the sprocket on, can you see the wire potruding to the outside diameter of the sprocket drum?