044 air leak - oil pump bushing?

[mudfly]

Hello.

I am working on an early 044 that scored the piston and cylinder. Going back together after replacing piston and seals with OEM. Now I have a leak on the PTO side between the crank and the oil pump bushing. It's bubbling out that small crevice at about 5 psi.

Trying to figure out how that is supposed to seal. Did I put the PTO side seal in wrong or not far enough? It's flush with the outer race of the bearing.


Thanks in advance.

 

[atpchas]

Unless the wear between the crankshaft and bushing is excessive, the small amount of leakage is not worth worrying about (IMHO). The IPL shows an o-ring under the bushing but I've yet to see an 044 with that o-ring in place. Some folks pack the recess where the o-ring would go (if they had one) with grease which will certainly slow/stop the leak for a time but is likely not a permanent fix. I wouldn't bother with that if you already have the bushing and seal in place.

 

[cookies]

looks like the lip seal is rolled out along the top of the crank journal when zoomed in on your picture

 

[mudfly]

Unless the wear between the crankshaft and bushing is excessive, the small amount of leakage is not worth worrying about (IMHO). The IPL shows an o-ring under the bushing but I've yet to see an 044 with that o-ring in place. Some folks pack the recess where the o-ring would go (if they had one) with grease which will certainly slow/stop the leak for a time but is likely not a permanent fix. I wouldn't bother with that if you already have the bushing and seal in place.

Thanks. Seems like a strange design to me. Not sure why seal is on the bushing versus the crank shaft.

 

[mudfly]

looks like the lip seal is rolled out along the top of the crank journal when zoomed in on your picture

Thanks. I will take another look at it tomorrow, but that isn’t where it’s leaking.

 

[L34]

Just done my 044.
Put some permatex 515 on shaft and inside bush.All good,no leak.

 

[mudfly]

Just done my 044.
Put some permatex 515 on shaft and inside bush.All good,no leak.

Follow up question and maybe what is causing the leakage here. With the seal in, and just turning the crank by hand, should that bushing turn with the crank or stay in one place?

The drag from the seal is keeping the bushing stationary when I turn the crank by hand. I can turn it, just curious if it is supposed to turn or stay stationary.

 

[Roygor]

Put grease in the cavity where the O-ring was supposed to be. Then install the cover washer and clutch (just good and hand tight) then pump it up again and see if it holds pressure. I use an old clutch center hub when I'm testing.

 

[L34]

As above
Need clutch fitted to hold pressure on bush.

 

[scallywag]

Has the bushing been checked for cracks?.

 

[mudfly]

Has the bushing been checked for cracks?.

It’s not cracked. It was definitely bubbling out from the annular space between the bushing and the crank shaft.

 

[mudfly]

Put grease in the cavity where the O-ring was supposed to be. Then install the cover washer and clutch (just good and hand tight) then pump it up again and see if it holds pressure. I use an old clutch center hub when I'm testing.

I’ll do that and try it. So when there is pressure inward against that bushing it spins with the crank?

Do I need to have the worm gear in also when I’m testing?

Much appreciated.

 

[L34]

No worm required
Yes spins with crank.

 

[gary courtney]

I’ll do that and try it. So when there is pressure inward against that bushing it spins with the crank?

Do I need to have the worm gear in also when I’m testing?

Much appreciated.

grease or hylomar blue or moto seal will solve the problem. when clutch is put on the bushing will turn with crank

 

[mudfly]

Thanks for the answer.

 

[stihltech]

Once upon a time there was an oring but it was never in the parts breakdown.Has since disappeared. The proper fix is grease in the cavity. The clutch tightens on the bushing and doesn't leak. I would not use a sealer as it should be removable.

 

[mudfly]

Once upon a time there was an oring but it was never in the parts breakdown.Has since disappeared. The proper fix is grease in the cavity. The clutch tightens on the bushing and doesn't leak. I would not use a sealer as it should be removable.

Thanks again. Put some grease on the back side and it sealed right up. Now to see if I can remember how to put this all back together .

 

[mudfly]

Got it reassembled. The only aftermarket part on this is the muffler. I have the original but I believe it’s the European model. Way to choked up. So I put this dual port one on for now.




Not as nice as the 044 that @gary courtney is building. That one is a beauty, but I’m hoping mine will run well enough.

 

[Roygor]

Nice job, you'll love running it.

 

[Catfish044]

I’m getting some strange running issues on 44 I just built , new carb , new fuel and impulse line at rebuild , I used hyway crank seals , saw pressure test and vac test fine , turn engine over by hand gauges holds steady , last time I checked it held pressure and vacuum for at least 15 min , just wondering when it’s running those seals are leaking ? Turn the saw on its side flywheel up she want to die