Danger Mouse
Super member
I have read a few comments from owners (and include myself) where that plastic crankcase drain bung would leak oil.
Not a huge amount in my case...more of a slow weep.
Hills sent me a new bung complete with attached washer and that did seem OK for about 2 weeks, and I thought it was now sorted.
Sadly no, it was still weeping.
Looking at both the original and replacement bungs I noticed that the attached washer was very tight on both of them.
Could only remove the washer by 'unscrewing' it back along the threads of the bung.
So when you try to actually tighten the bung (and it's a plastic bung going in to a plastic crankcase) you can't give it a mighty heave to seal it tight.
As supplied I thought that the tight washer was stopping the bung from fully seating home against the washer surface.
So I ran a small round file around inside the hole of the washer to allow more freedom. Not a lot, just a mere scrape is enough to let the washer turn freely.
If you don't have a file then sandpaper or even lightly scrape around with a knife blade.
It's right when you can pop the washer back on to the bung and it spins freely (not hung up on the threads of the bung).
Now I have put the original bung back in (with the modified washer)...and no more leaks/weeps.
The tight fitting washer had been stopping the bung from fully seating. Now it's behaving as a good washer should.
So if you are having the same problem then drop the bung out, remove the washer by unscrewing it back out along the threads, and lightly make the hole in the washer a tad larger.
Yes, you can prop the pump back on a block of wood so that your oil won't come out as you do the washer job.
Not a huge amount in my case...more of a slow weep.
Hills sent me a new bung complete with attached washer and that did seem OK for about 2 weeks, and I thought it was now sorted.
Sadly no, it was still weeping.
Looking at both the original and replacement bungs I noticed that the attached washer was very tight on both of them.
Could only remove the washer by 'unscrewing' it back along the threads of the bung.
So when you try to actually tighten the bung (and it's a plastic bung going in to a plastic crankcase) you can't give it a mighty heave to seal it tight.
As supplied I thought that the tight washer was stopping the bung from fully seating home against the washer surface.
So I ran a small round file around inside the hole of the washer to allow more freedom. Not a lot, just a mere scrape is enough to let the washer turn freely.
If you don't have a file then sandpaper or even lightly scrape around with a knife blade.
It's right when you can pop the washer back on to the bung and it spins freely (not hung up on the threads of the bung).
Now I have put the original bung back in (with the modified washer)...and no more leaks/weeps.
The tight fitting washer had been stopping the bung from fully seating. Now it's behaving as a good washer should.
So if you are having the same problem then drop the bung out, remove the washer by unscrewing it back out along the threads, and lightly make the hole in the washer a tad larger.
Yes, you can prop the pump back on a block of wood so that your oil won't come out as you do the washer job.