PTT, Yamaha, check balls in oil pump

[BaffinBay]

Engine: F150TLRC (2004 four stroke), PTT assembly 63P-43800-00-00, 3 ram SHOWA. The main valve arrangement in the oil pump uses (4) tiny check balls. The upper and lower check balls have different part numbers: upper 64E-43858-00-00, lower 72X-43858-00-00. These are items 18 and 7 in the diagram. What is the dimensional difference? Are they interchangeable? Thank you boscoe99 for the image.

PTTcloseup.png

[99yam40]

I do not think you will find specs on those.
Maybe you will need to use a mic to measure.
should only need to orher one to measure to see which one it is to compare.

also I see the balls in pic are 5 (not 7) and 18 and 12


I never found any specs on the main jets in my motor so I ordered one new one and used drill bits to have a go no go measure of the new and the ones in my motor and discovered someone had drilled out the ones in my carbs.(I am the 3rd owner of this motor) that was causing a high speed miss.
I replaced all 3 and motor runs good now

[boscoe99]

I am guessing he is comparing 5 and 18.

I suspect that only Fukimotoyama at Showa knows the difference between the balls.

[BaffinBay]

99yam40 and boscoe99, thank you for that catch. Correction: items 5 and 18. The two check balls that I have in captivity are 3.16 mm / 1/8" in diameter. I am not sure if they are #5 or #18, or perhaps it doesn't matter. I have both part numbers on the way from a Yamaha dealer, bagged and marked, ordered March 3, partial backorder, ETA a week out for the complete order. It is best to do this pump inspection work over a fluffy beach towel! Stand by. I will post dimensions for next time.

[boscoe99]

Have you even noticed that concrete floors are the colour of steel parts?

[99yam40]

even if they were not the same color. those little balls just bounce and roll to never never land when you drop them.

[boscoe99]

And they zig zag. Go west when it appeared they went east.

[99yam40]

I hate it when they hit my foot or shoe and then you have no idea which way the head.

[panasonic]

I lost a 1/16" carbide indentor ball for a Rockwell hardness tester awhile back..brand new. Trying to put it in its holder and dropped it on the shop floor..$300 ball gone!