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TOPIC: DT2 and RT2 oil pump drive

DT2 and RT2 oil pump drive 13 Aug 2019 13:31 #1

  • run103
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I am putting a RT2 engine into a DT2 frame but I am using the oil pump from the DT2. The RT has a coarse thread worm gear to drive the pump and the DT has a fine thread Can you use the fine thread on the RT as long as you make sure it pumps enough.
Doug

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DT2 and RT2 oil pump drive 13 Aug 2019 14:17 #2

  • DEET
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"Can you?" yes
"Should you?" No

It won't deliver enough oil at the right time.
That is why they are different.

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Yamaha@nc.rr.com

Where the Yamaha Enduro is still a current model...

DT2 and RT2 oil pump drive 13 Aug 2019 15:01 #3

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I never realized all that but i've never tried swapping pumps around either. All good info.

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DT2 and RT2 oil pump drive 13 Aug 2019 15:28 #4

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Deet
So the coarse thread causes the pump to turn faster
Doug

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DT2 and RT2 oil pump drive 13 Aug 2019 15:31 #5

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Deet So do all the big bores have the coarse thread worm gear and 250's and down have the fine thread
Doug

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DT2 and RT2 oil pump drive 13 Aug 2019 16:20 #6

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I have not compiled a list that would provide data on that.
The pitch of the ring gear has to match the pitch of the worm gear.
There was a service bulletin for the RT1 stating they needed to change the pitch because it wasn't oiling properly. You would have to measure the pitch to determine which ring gear matches which worm gear.

If a DT1 pump was OK for a RT1, why would Yamaha make a separate one for the RT?
When the early RT1 pump wasn't providing enough oil, they made a change. They knew what they were doing.


I tend to stay with proven engineering.
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Yamaha@nc.rr.com

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DT2 and RT2 oil pump drive 13 Aug 2019 16:23 #7

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Not only is the pump gear different, but the pulley is different.


All those things have to work together.
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Yamaha@nc.rr.com

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DT2 and RT2 oil pump drive 14 Aug 2019 00:32 #8

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DEET wrote: I have not compiled a list that would provide data on that.
The pitch of the ring gear has to match the pitch of the worm gear.
There was a service bulletin for the RT1 stating they needed to change the pitch because it wasn't oiling properly. You would have to measure the pitch to determine which ring gear matches which worm gear.

If a DT1 pump was OK for a RT1, why would Yamaha make a separate one for the RT?
When the early RT1 pump wasn't providing enough oil, they made a change. They knew what they were doing.


I tend to stay with proven engineering.


This was probably the one and I probably got it from the Tech Library.

Does anyone know if Yamaha issued an updated schedule?

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DT2 and RT2 oil pump drive 14 Aug 2019 08:12 #9

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Well this started people thinking..Anyhow I have connected a coarse thread pump and when i get the clutch working I will test the pump according to the bulletin listed here. I have 4 pumps and all 4 have different pulleys Thanks again guys for all the reply's
Doug

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DT2 and RT2 oil pump drive 14 Aug 2019 13:53 #10

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The pulleys have different markings depending on the model. Maybe this will help:

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The hours spent riding my Enduros is not deducted from my life span.
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