'How To' Yamaha oil pump testing

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Here's some info on Yamaha pump testing using a cover to mount pump, some accessories with a cordless drill to see if your rebuilt or pump is working correctly.

Here is a '84 RZ350 pump off Brian Baldwins 350.



Video link:

https://photos.imageevent.com/supertune/rd400enginebuildpics/20191015_113338.mp4

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Guillermo's pump setup.






Video's of Guillermo's RD400 setting up the final throttle cables with the TM34's

https://imageevent.com/supertune/guillermosrd400videos?

p=1&n=1&m=-1&c=3&l=0&w=4&s=0&z=3

https://imageevent.com/supertune/guillermosrd400videos?p=0&n=1&m=-1&c=3&l=0&w=4&s=0&z=3


Always look for this thrust shim that goes on the end of the worm gear! Guillermo's was missing!

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Scott's '76 RD400 pump.



Scott's pump was messed with before I got it in for a rebuild and his worm shim washer was missing...nope found it!!  it was on the pump post for shiming!   



Testing video:

https://photos.imageevent.com/supertune/rd400enginebuildpics/20191021_184534.mp4

[quocle603]

THANK YOU CHUCK!

[NYSingh]

Awesome! Checked and my pump definitely didn't have that washer. Now to try and find a replacement 

Is the pump effectively non-functional without that washer on the worm gear?

Stupid question - when you're testing the pump, is your drill set to forward or reverse? (from your photos the drill looks to be set in the forward (clockwise) position, but want to confirm)

[SUPERTUNE]

I got an email about a rebuilt pump not pumping at idle.
This was my reply to him and wanted to add this bit of info here...

I have found the the rebuild kits all have aftermarket gasket for the 4 bolt housing. They are thicker than the oem gasket. When the gasket is thicker it takes up the idle shimming and takes sometimes a lot of extra shims to get the clearance back.
Most people that rebuild the RD pumps don't know to re-shim after the rebuild.
The other issue can be the cam lobe inside the pump wears out over time and may need to be replaced with another one that may not be worn so much. Remember these bikes are very old now and the pumps had run old school petroleum oil for many years until we started getting synthetic oils that are much better at keeping the pumps from wearing out so much.

[JB Weld]

Thanks for posting this.

I am the person that emailed Chuck. I ordered an assortment of shims this morning. This evening I decided to take the plate and shims off the end of the shaft, just to make sure it would stroke, and was relieved that it did. With the plate and shims on (no clearance) the pump wouldn't stroke at all.

[m in sc]

great info chuck.

just did my r5 pump a week ago.

interestingly, as aside note, the r5 pumps have a rubber seat on the check valves, pretty sure the rds were all metal to metal, and the output fittings are slightly different (larger) diameter where they press into the pump.  This was on my 70 which is a very low number one, not sure if it changed on the r5s after that or was the same till the rds came around, but externally the pumps look the same (just fyi).

[Arrow]

Nice testing rig Supertune.

Many of those thrust washers seem to be missing these days. I send an advice note early and make reference to it, to give me time to put one in the box before sending. If your pump has a pressed in steel sleeve arrangement where the 8mm part of the wormshaft fits in, then it doesn't have the thrust washer as well. Pumps up to (around) 1974 had the steel sleeve. There is of course change over time and different markets.

Sent from my SM-G973F using Tapatalk

[so-cal-sdr200]

If anyone needs that oil pump thrust washer, ( 90201-08624 ), let me know.
 I ended up with several after a partzilla snafuuu and got some from Ebay.
 Turns out my '73 RD250 does not use that washer.
 I have a few reserved for Ed Erlandbach, but 4 or 5 are just going to sit
 in a box somewhere till I die.
 
 Contact me with an address and it will cost me .50cents to mail one to you.

Wish I had tried Chuck's test procedure before installing my rebuilt pump.
 May take it apart again just to be sure.
 Cheers, Jeff

[JB Weld]

Wish I had tried Chuck's test procedure before installing my rebuilt pump.
 May take it apart again just to be sure.
 Cheers, Jeff
[/quote]

I did mine after it sat assembled for 4 years. I scrambled to throw my engine together after purchasing a house. I got busy after moving and decided to test it after seeing Chuck's vid. It worked but also showed that the housing gasket was thicker than original and required more shims in order to operate at idle.

I also found that I never gapped the rings either. Glad I took it apart.

[Arrow]

Why not just use the genuine Yamaha gasket?
Perfect every time.

Sent from my SM-G973F using Tapatalk

[so-cal-sdr200]

Help,  ,  Oil pump test not working out as EXPECTED.
 Going by the instructions above. I am having an issue with a newly
 rebuilt pump.
 I got the bleed procedure completed. Not getting any bubbles in the
output tubes. The minimum stroke is near the lower measurement, but,
 the pumping using Chucks drill method was done at MAX throttle position.

 I am getting different flow volume between the lower output tube and
 the upper tube. More than double... See picture.

 Wish I could post a video, don't know how... Don't know how to link a high
 def picture either.

 When running the drill motor the piston seems to make a long full stroke
 and then makes a short stroke. When the long stroke pumps it fills the lower
 tube, then the shorter stroke moves just a little fluid in the upper tube.

 Found a video on YouTube where a gent disassembles a Yamaha pump.
 Looking at the internal pump cam it appears that there is only one cam ramp.
 So I don't know how I can be getting different stroke length...

 Anyone seen anything like this before?
 This is the last thing I need to do to complete my year + long restoration.

 Thank you, Jeff in So. Cal.

[Arrow]

Hi, you said you completed the bleed procedure and had no air in the lines. Was the photo taken before you did this?
Your camshaft should look like this;
There is also a single lobed camshaft, would explain the clip you have seen. The single lobed shaft can be l/h or r/h.

Sent from my SM-G973F using Tapatalk

[so-cal-sdr200]

You know what!! The video I watched was for a DT400 so of course there was only
 one ramp on the pump cam!!!
 I did not do the pump rebuild, so, I did not see the pump cam....
 The picture was after I ran the pump at least 200-400 strokes and
 drained the output tubes 3-4 times.  So the volume is not representative
of the output-vs-strokes.
Took the picture as a last resort to post a "help" here.

 So maybe a disassembly is in my future..?
 thanks for getting back so quick.