Topic: 750 Oil Pump Rebuild Kit

[Mr.Miller]

G'day brains trust, hoping someone is able to assist as I'm having possible wet sumping issue with my 750K. Looking for an Oil Pump Rebuild Kit Like This in Australia - Everything I've managed to find is in the US with $130USD shipping. 

Cheers,

[HondaMan]

Some ideas, just in case you can get the needed parts separately Down Under...
The paper gasket comes in almost all gasket sets. It is waxed paper.
The larger O-rings are a fixed size, and are seldom 'bad' anyway (2x66).
The smaller O-rings likewise are a fixed size, and also don't wear out (2.4x15 or 2.5x15).
The center seal is an important item: the 1977/78 Gold Wing pump uses the same shaft seal, so maybe check Down Under in their parts fiche to see if they might have one?
Often, if the oil tank is draining into the crankcase after the bike sits a while, the check valve piston is sticking in the 'tunnel' where it lives. This can be from gunk & varnish (caused by sitting) or by a warped 'tunnel' because the metals used were not terribly expensive in nature. I have successfully honed that port round again with a few seconds of a small (real small) brake hone and a drill. I've also done it with a dowel that had a slot cut in one end so I could wrap some emery paper (fine) on the end and spin it a while in that port so the piston could slip easily inside that tunnel.

Those springs don't wear out, either.

[Mr.Miller]

Thanks for the info HondaMan, very helpful. I had thought about removing and inspecting though didn't want to find myself with a handful of non-replacable parts and a bike that's no longer running. Will see what I can find local for replacment center seal and go from there

Being new to the CB world, I'm gussing the issue I'm having is wet sumping as I really only get the bike out once a month if I'm lucky. Though, in saying that I get more cold start smoke that I would expect even if I let the bike site for just a few days. Clears up very quickly once ridden.

Cheers,

[RAFster122s]

Good idea to park bike on center stand instead of side stand...fewer issues with carbs and oil that way...

[HondaMan]

You will find that center shaft seal in the oil pump to be a unique part: it is an inside-out seal design(!). The steel shell is bare and on the outside of the rubber. That's the only real tricky part.

When you walk up to the bike after it sits a day or more, is the oil level still normal in the tank? Or, does it wet-sump after riding it a while?
Reason I ask: if it just lowers the oil level in the tank, this is often the little plunger in the discharge side of the pump, being stuck slightly open until it cools off (and shrinks a little), returning then to normally-closed position. If it wet-sumps after starting it up and running, it is a bigger trouble, usually caused by scored rotors inside the pump.

[Mr.Miller]

Hard to tell from a glance with the custom oil tank fitted on the bike. Usually once warmed up and ridden it clears and is fine until parked/cooled down for a while. Deffintly worse when it's been sitting in the shed for a long period though.

I have to replace the clutch in it shortly so will pull the pump out whilst at it and take a good look over it. Appreciate the assistance.

C,

[newday777]

Hard to tell from a glance with the custom oil tank fitted on the bike. Usually once warmed up and ridden it clears and is fine until parked/cooled down for a while. Deffintly worse when it's been sitting in the shed for a long period though.

I have to replace the clutch in it shortly so will pull the pump out whilst at it and take a good look over it. Appreciate the assistance.

C,

You should have included the information that you don't have a stock oil tank and the part that it clears and is fine once warmed up.
What lengths of time are you saying???

You know that the manual says to run the bike first before you check the oil right? Are you doing that and oil level is fine?

[newday777]

Hard to tell from a glance with the custom oil tank fitted on the bike. Usually once warmed up and ridden it clears and is fine until parked/cooled down for a while. Deffintly worse when it's been sitting in the shed for a long period though.

I have to replace the clutch in it shortly so will pull the pump out whilst at it and take a good look over it. Appreciate the assistance.

C,

Piecing together your replies in this thread, it appears(maybe I'm wrong?) you wrote this more on the smoke you have on startup or is it the oil level dropping in your custom tank before starting up that you are concerned about? Have you done anything yet to rectify your situation? (You've let this thread unfinished so far.)
If it's the smoke and and not the oil level(you really haven't answered the question asked of your oil level in the replies), it might be old valve seals or worn out valve guides causing the start up smoke as you say it goes away after it runs for a bit.
Hopefully you have pushed the notify button to get an email when someone replies to this.....

BTW I missed that you are new to the forum so welcome aboard.
You should go to the new members section and introduce yourself and your bike(how long you have had it, did you build it, what's in it, post some pictures of it, etc etc)

[newday777]

Hard to tell from a glance with the custom oil tank fitted on the bike. Usually once warmed up and ridden it clears and is fine until parked/cooled down for a while. Deffintly worse when it's been sitting in the shed for a long period though.

I have to replace the clutch in it shortly so will pull the pump out whilst at it and take a good look over it. Appreciate the assistance.

C,

Do you only leave it parked on the side stand? Have you pulled the spark plugs just after startup to see which cylinders have oil on the plugs?
I did a search of your posts and saw this picture of your bike, and see the centerstand has been removed. It appears you have a F model Supersport. What year is it?(should be a model year on the steering neck tag if imported from the states??) I ask as if it is a 77 or 78 F then the valve guides are a usual wear item that need replacement early on.
Do you have a paddock stand to park it upright? Or a tire chock?