Another oil pump ratio post. SE50, SA50, SA50P

[yamahauler660r]

We all know a oil pump on a 94-01 sa50 (elite SR) flows more than a sa50p (elite S). My question is what is the ratio difference between a unrestricted sa50 SR pump and a 87 se50 & se50p pump? (Se50 & se50p pumps have the same part #) why would the pumps be the same on a restricted & non restricted SE?? )) where the SA pumps are stamped with GS7 or GS7V, the SE pump is stamped with GR1.
Being a Michigander my interests change with the seasons, so every summer I try to figure out where I left off from the previous fall. And with 15 mopeds alone I have to make notes of everything.
That being said I've had all 3 pumps disassembled previously, and I think the sa50 (gs7) and the se50 (gr1)are the same or real close. But this is one of the details that got lost in the snowstorm. You can clearly tell on the different size of the notch on the top of the gear inside the pump. I have a gr1 pump on my SpreElite and a gs7 pump on my elite S. I also have a gs7v that was used as a control on my comparison.
I wouldn't run a restricted pump on either af16 engine of mine so the guts must have looked to match the unrestricted sa50 pump to my eye. I think I bought a "SR pump" from a member years ago and the gr1 pump is what arrived. That is when I inspected them.

I know this has been covered in the past but I could not find a good answer.

So if they are the same flow this opens another door for the guys looking for a unrestricted sa50 (elite SR) pump
But if the sa50 and se50(p) pumps are not the same flow
I need sr oil pump (GS7 stamp)

[bonesv]

SE50 was only made for one year and the pump is no longer available from honda.

[yamahauler660r]

That is a fact. My question is about the mix ratio between se50 pumps and an unrestricted sa50 pump. I have been looking for a SR oil pump for years and I have multiple se pumps.

[Wheelman-111]

Greetings

One resourceful Forum member once set up his pump to spill into a catch bottle. Then he pre-mixed fuel for the tank and ran the scooter until he'd burned some known quantity of gasoline. Finally he measured the output of the oil in his catch-bottle and gave us the ratio.

Another way might be to set up an SA pump in a twist drill or lathe, spin the pump for some period of time, and measure. Then switch to the SE and compare outputs. Since the ~2% SA ratio is known, it'd be pretty easy to calculate the output of the SE pump with the results.

[yamahauler660r]

I did see that post.
While that member went above and beyond I will do a mini version of that members experiment. I will use an electric drill (this is how I do a final oil pump bleed on rebuilds)and time how long it takes to fill a small cap of some sort. Just for a comparison. For a more, equal, or less answer
I was hoping someone else did the dirty work and had an answer, but I will post back with my results hopefully this weekend.

[vintagegarage]

I am repairing a 2000 Elite S that blew up while running a desrictricted exhaust and airbox, but with no changes to the oil pump which was not wired open. The left main crank bearing got trashed as well as the piston and cylinder. I ordered an SR dual throttle cable and was going to use the original S pump with the dual cable, but based on the first line in the original post in this thread, I ordered an SR oil pump. Did I wAste my money or does the SR pump really flow more than the S pump when both are fully In the WOT position?

[yamahauler660r]

The SR pump definitely pumps more oil. As wheelman said, a member did an experiment with a catch container with each pump. He came up with ratios if I remember right.

[vintagegarage]

Thanks for the quick reply.. I'll go with the SR pump.. pretty expensive upgrade.. going to have twice in the Elite than it is worth when all done, but it at least saves it from the junkyard..