PA50II Oil Change

I was thinking (and you can always get in trouble doing that) that a oil change was in order for the rear wheel gearbox on my Hobbit. In checking the book there are very specific instructions on where to drain the oil and the amount to refill with (75cc SAE90), but I can find no reference to how to get the oil back in.

The book does not show any fill hole and I can find no obvious fill point.

Has anyone done this?

Help please.

Re: PA50II Oil Change

The fill hole is the 14mm (?) bolt right next to the pedal/drive switch lever pivot.

i think it's worth a change just to assure the right amount of oil is in there.

There's a vent hole at the top of the inside of the casting and oil easily leaks out when the bike is laid on it's right side or the wheel is removed and repaired or something..

Re: PA50II Oil Change

Thanks Joe. The world of knowledge out there just boggles my mind.

Re: PA50II Oil Change

anytime.. btw, what book you were referring to? The Shop manual HERE does have a nice exploded view of that gearbox, page 98 of the .pdf file. It points to a drain bolt but i see no "very specific instructions on where to drain the oil" that you referred to.

make that page 87.

page 87 according to Acrobat Reader.

Re: make that page 87.


I have a shop manual for '78-'81 and the exploded view is on page 73 of my book.

Maybe I mispoke; I see the drain bolt very clearly shown but I can not see the fill point.

I looked at the top bolt but there is no opening into the gear chamber.

Re: make that page 87.

The fill and drain point is the same hole. I use a small funnel with a short plastic tube that fits in the bolt hole.. tubing is attached to the funnel with some electrical tape. The bolt is notated as a "drain bolt" on the '83 PA50 manual.

To see the vent, you have to remove the gearbox from the wheel and look at the top-rear side of it's casing to find the little vent hole. When oil leaks from there, it ends up in the rear wheel's hub cavity.

That manual is nice to have.. Im pretty sure the only Hobbit manuals available anywhere on the net are on the page i pointed to.

Re: make that page 87.

That doesn't make sense. How do you drain and fill at the same point? Do you have to lay the bike over on its side when you fill it?

Re: make that page 87.

To drain without removing the wheel, tip the bike over on it's left side. To refill it , see attachment.

I've never had to or tried to drain the box with the wheel still mounted on the bike.. but i do refill it with the method shown once a wheel was remounted.

75cc is not a whole lot and if you don't tilt the bike too far to the right, you might get away with using just the small funnel stuck in the hole with no oil leaking out the vent.. If you lay it on it's right side, oil will leak out.


Re: make that page 87.

Thanks for the drawing.

It is hard to believe that Honda would mis-engineer this.

It is just not reasonable that you drain and fill thru the same hole.

I'll give it a try.


Re: make that page 87.

SilverFox, Honda has left a lot to be desired in some of their engineering. They have also had good things too.

All these companies miss perfection when you view them up close and personal. don-ohio

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