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pesky air in oil lines R5, fixed

Started by m in sc, June 18, 2020, 12:01:33 PM

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m in sc

So, when running clear lines, theres always the possibility of seeing air. Not always bad.

I rebuilt the pump on my 70 2? weeks ago, and it was ok, just did preventative. however, the LH cyl with the longer line always seemed to get air in it from the cyl. it never starved, the plugs looked, good, etc. even did some long hwy runs, but kinda drove me nuts.

the RH side, no issues. So my theory was that, the longer line with the check valve being so far down the line was allowing air from the cyl to expand in the line, then the oil was at the stroke of the pump, going back tot he cyl, effectively with no loss of oiling.  Kind of a bladder efffect.

I like clear lines, so i was going to keep them.
To verify it wasn't the check valve at the pump, i swapped lines. no difference, stayed on the LH longer line side. Only happens after longer steady runs and the pump is working perfectly otherwise.  I had put well over 150 miles on the pump post rebuild, i do not believe that was the issue. as said, it never failed, was just preventative.

Now, on triples, and suzuki twins, the checkvalves are at the output side and the lines are rigid, so it doesn't see this phenomenon.

What felt would be good was a 0 psi check valve inline. I considered plastic ones from mcmaster, but being bored int eh shop one night. i made my own out of brass.

I pirated a fitting from my spare pump parts and s check ball. took this brass standoff i had, and drilled a 4.5 mm hole down it. then,   drilled a 1.75 hole though it all the way to come out the threaded section.  then, counter drilled the top 7mm for the pump fitting to fit snugly into.

I measured the ball and spring, and then measured the fitting and brass i machined so that the spring would just touch the ball when assembled.

dressed the 4.5mm drilled hole at the bottom of the bore with a spare check ball, peening it down into the v cut left by the drill to shape the ball seat in the brass, then removing it.

I then  turned the brass fitting on the lathe to make a nipple and and take some of the hex off. chamfered the end of the nipple fitting by hand, then cleaned in brake clean then acetone.

the brass fitting is 3/8 across the hex for reference.

i then used  afresh ball and borrowed spring  from an rd oil pump, pressed the 90 degree oil fitting onto the brass body, then soldered together.

after it cooled, for sure, worked fine.

here it is on the bike. yes, overkill but its good to go.



for visibility:



where it sits resting on the case:




Czakky

Lord know I've been down that road...  :clap:

Kawtriplefreak


Czakky


m in sc


rodneya

My 74 did that for a while after I rebuilt the pump. Made me a bit paranoid, but it went away after a few rides.

SUPERTUNE

RD's will have air issues in clear lines with zipties... I'm a big proponent of testing my pumps before install, then only using Yamaha oem black lines and the stock band clamps. Same for the feed lines from the tank to the pump using the spring clamps.
All still available from Yamaha.   
Aftermarket lines and zipties just don't work for me.
Chuck
RD machine work, boring, porting, cranks and engine building.


Chuck 'SUPERTUNE' Quenzler III
Team Scream Racing LLC
1920 Sherwood St. STE A
Clearwater, FL. 33765
cqsupertune@tampabay.rr.com

SUPERTUNE

This would have been easier Mark...
OEM Yamaha oil pump inline check valve      8CH-1316A-00-00 About $20 each.
I use these on the late model TZR's NSR's and Aprillia's I work on when hard to get oil pump check valves are fussy.
C
RD machine work, boring, porting, cranks and engine building.


Chuck 'SUPERTUNE' Quenzler III
Team Scream Racing LLC
1920 Sherwood St. STE A
Clearwater, FL. 33765
cqsupertune@tampabay.rr.com

m in sc

#8
wish i had known about that check valve  :dawg: 

i did test the pump, its functioning as it should, for sure (actually always did). But at 50 yrs old, figure a preventive rebuild was in order.
I considered going back to the black lines, but wanted to make this work... and i was waiting for my carbs to show up.  :toot:  the lines are actually blue urethane, not 'clear' per-say.  They absolutely do not leak, of that i can assure you. the clear vinyl that gets rock hard? oh yeah, those are problems (too hard over time and leak at barbs), as do the tygon lines. (too soft).  The zip ties TBH aren't even necessary w the blue line.