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Air in oil feed
- 45chop
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Air in oil feed was created by 45chop
Hi there,
Anybody know if this is normal for RT3 360, back pressure from engine creates air bubbles in the oil feed. Hard to film when moving, I can see the bubbles move when turning over the engine. I see DT400 has oil feed relocated to carb side therefore not effected by back pressure. Is it a problem that was modified by Yamaha or not to worry about
Thanks
youtube.com/shorts/O-Q2STHNd3I?feature=share
Anybody know if this is normal for RT3 360, back pressure from engine creates air bubbles in the oil feed. Hard to film when moving, I can see the bubbles move when turning over the engine. I see DT400 has oil feed relocated to carb side therefore not effected by back pressure. Is it a problem that was modified by Yamaha or not to worry about
Thanks
youtube.com/shorts/O-Q2STHNd3I?feature=share
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- Tinkicker
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Replied by Tinkicker on topic Air in oil feed
I have no personal experience on RT3, but I suppose it depends on how far down the line do the bubbles travel. A couple of mm should not be too much of a problem.
Half an inch or so may mean your outlet check valve in the pump is stuck open. Edit. Having found your vid, I would say dirt in your outlet valve. The bubble should move towards engine only.
Run premix if you must. But do not run the engine as is.
Half an inch or so may mean your outlet check valve in the pump is stuck open. Edit. Having found your vid, I would say dirt in your outlet valve. The bubble should move towards engine only.
Run premix if you must. But do not run the engine as is.
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- 45chop
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Replied by 45chop on topic Air in oil feed
Thanks for the reply, I’ll strip down the pump and have a look at the check valve.
17 Jun 2023 08:28
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- MarkT
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Replied by MarkT on topic Air in oil feed
I would not worry about it... bubble is "bouncing", not moving towards pump.
I believe there are reasons Yamaha used very small ID hose that is not transparent. One is that oil might move around that bubble and give the illusion no oil is pumping. (Very common illusion that also happens with clear fuel line... many people have spent countless hours trying to "fix" a fuel flow issue because the clear line does not fill with fuel when petcock is turned on). And a smaller ID oil line is less likely to trap bubbles.
What happens to bubble when engine is actually running? Are you getting normal smoke?
Fix is to use original hose.
I believe there are reasons Yamaha used very small ID hose that is not transparent. One is that oil might move around that bubble and give the illusion no oil is pumping. (Very common illusion that also happens with clear fuel line... many people have spent countless hours trying to "fix" a fuel flow issue because the clear line does not fill with fuel when petcock is turned on). And a smaller ID oil line is less likely to trap bubbles.
What happens to bubble when engine is actually running? Are you getting normal smoke?
Fix is to use original hose.
1963 YG1-T, 1965 MG1-T, Allstate 250, 1970 CT1b, 1971 R5, 1973 AT3MX, 1974 TS400L, 1975 RD350, 1976 DT175C, 1976 Husqvarna 250CR, 1981 DT175G, 1988 DT50, 1990 "Super" DT50, 1991 RT180, 2017 XT250
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17 Jun 2023 08:30
#4
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- asco
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Replied by asco on topic Air in oil feed
My experience with clear oil line produces no bubbles. The oil line was installed without completely bleeding “the tank to pump line.” Or perhaps’ the oil pump was not bled at all.
Remove the screw. Bleed. You’re done.
a
Remove the screw. Bleed. You’re done.
a
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1971 CT1-C (BRANDY)
1970 DT1-C (MONICA)
1972 AT2M (ZIFFLE)
1970 CT1-B (HULK)
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1971 CT1-C (BRANDY)
1970 DT1-C (MONICA)
1972 AT2M (ZIFFLE)
1970 CT1-B (HULK)
1971 DT1E (GINA)
1970 CT1-B (CLIDE)
17 Jun 2023 08:40
#5
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- 45chop
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Replied by 45chop on topic Air in oil feed
Pump is definitely bled, I can manually move the oil and bubble until pipe is full of oil. I do suspect there’s a non return valve issue but the pump I have is unlike the one in my manual. I’ll try posting a video, see if anybody knows where the check valve is located on this pump.
17 Jun 2023 08:57
#6
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- 45chop
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Replied by 45chop on topic Air in oil feed
17 Jun 2023 09:03
#7
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- Gr8uncleal
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Replied by Gr8uncleal on topic Air in oil feed
Replace the clear hose with genuine Yamaha black (still available), bleed and then forget about it.
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17 Jun 2023 09:03
#8
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- Tinkicker
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Replied by Tinkicker on topic Air in oil feed
Check valve ball and spring are under the small brass spigot. It is a very tight push fit, not screwed in.
I had to grip mine tightly in a soft jawed vice this morning, twisting and pulling at the same time.
I had to grip mine tightly in a soft jawed vice this morning, twisting and pulling at the same time.
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- 45chop
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Replied by 45chop on topic Air in oil feed
I wish I could be so carefree, got a fair bit of time and energy into this little bike and they’re not exactly two a penny anymore and definitely not here in the UK. I like to be able to see what the oil is doing & it definitely looks weird right now but then again as you say black pipe was originally fitted so who knew what was going on.
17 Jun 2023 09:13
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