Oil Supply Location - Answer if you can . . .

Ding

Darn Tootin'
Joined
May 8, 2003
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Howell, MI
Were there any stock Yamaha triples that pumped the oil into the output throat of the rack mounted TM carbs? This would be into a fitting placed in the boss on the engine side of the carb where you would normally connect a synchronizing board to sync the carbs.

Or on the other hand, did all of them pump the oil to the fuel pump where it was mixed with the fuel. Sorry, my memory is malfunctioning again.

I just looked at a modified 99 SRX that has the oil pump output routed to the backside of the carbs. Is this stock, or from a different sled, or an aftermarket mod?
 

It is probably a Direct Oil Injection Kit, I know Bender sold them. Are the three lines connected together and then one line running back to the oil pump?
 
Triple X said:
It is probably a Direct Oil Injection Kit, I know Bender sold them. Are the three lines connected together and then one line running back to the oil pump?
Yes.

Do you know the expected benefit of this system? Was it to increase oil flow to modded engines that breath better?
 
It was to prevent the incorrect amount of oil/gas mix to the motor based on throttle position. If your sled were to idle for a few min, the mix from the pump to the carbs in stock set up will be lean untill the mix is burned off to match the throttle position. With direct injection, the oil pump is injecting oil into the fuel at the carb, so throttle position is matched to oil usage.
 
Ding said:
Yes.

Do you know the expected benefit of this system? Was it to increase oil flow to modded engines that breath better?

Grapeape is right, It synchronizes the amount of oil used with the throttle position. It's supposed to be more consistent with performance, less plug fouling and more forgiving jetting compared to the stock set up. I had the DOI on a mod Exciter SX seemed to work ok. I didn't go with it on my SRX7, I think if you had a completely modified race engine, it would be beneficial.
 


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