Britbike forum Forums British Motorcycle specific Brands Bsa bulletin board ZB34GS Oil Pump Drive Spindle

Hey all! First post here but hope to be many more in the future. Had the timing cover off the 1950 ZB34GS motor to check wear on the cams and while in there noticed the teeth on the oil pump drive spindle are showing some wear. Was wanting to install new spindle but wondering, can the spindle be removed out the bottom once the spindle retaining pin and oil pump are removed?

Also, has anyone installed one of the new "Hepolite" Oil Pumps on one of these motors? Is it worth the expense? Good preventative maintenance?

You may need to turn the engine over backwards a few times to wind it down off the drive pinion.

Do you have the service sheets?

Hi Herman and welcome to the forum.

Since you have a Gold Star, have a look around for the GS specific forum here as well. You might get more help if you post there although a lot of us watch more than one forum. Like me, and I have GS's too.

To answer your question, yes, the drive spindle should come out the bottom but, if the teeth have a sharp edged burr worn on them, (which is possible) the spindle could hang up in the case as you try to extract it. A diamond jewelers file works to take the burrs down.

I would have a close look at the old pump before splashing out for a new one. The originals are surprisingly durable and don't have to develop any real pressure, they just keep the lube flowing.

I notice you fly a 172. There are a number of pilots represented here. I used to own and fly a 1958 PA22/20-160 taildragger myself some years back. Great little plane and another great hobby, that is..... besides motorcycles.

Anyway, best of luck with your project.

Thanks Oz, and yes, I do have them ordered but not here yet!

Thanks Stuart! It's great to be part of the forum. Didn't realize there was a specific GS Forum, will check it out.

I did get the spindle out tonight and it came out without any problem. I'll open up the oil pump and have a look at the innards and decide what to do.

And yes, both two wheels and wings have been my two passions for most of my life, with aviation being my vocation for nearly 40 years now! You say you owned a Pacer? I'm currently working with a guy to get a PA22-160 from Canada imported and an US Airworthiness Certificate. The short wing Pipers are great little airplanes.

Will post some pics of the BSA when I get it back together.

I'm another flyboy.... PA-18 160hp on EDO 2000s. I grew up around them, got Private SEL in 1974. Also A&P with AI ... it's been my living for over 40 years