The 101 Association, Inc.
For the preservation and enjoyment of 1928 to 1931 Indian Scout Motocycles
"You can't wear out an Indian Scout"

Oil pump feed line air leak

  • 25 Sep 2017 8:34 PM
    Message # 5279183

    I have a running EGP 2082 riding it short trips for lack of time. This was a carnival machine purchased 25 years ago. Bottom end done I put the rest together. This bike belongs to member Lindsey Lytle. Being a four cylinder guy and some what a extreme motor builder of the fours this is the first twin I have ever built or worked on. I am a bare essential builder then then I complete it with the correct parts. By chance I put on a clear plastic tube as a feed tube to the oil pump. The oil is left on all the time and never over fills the bottom end.When I run the motor air bubbles are consistently being seen heading back up to oil tank. Would you think this is normal ? What is your idea on what is causing this.


         Conrad Lytle 

  • 25 Sep 2017 11:48 PM
    Reply # 5279421 on 5279183

    Is the connection between the clear plastic line and pump air tight?

    Do you bleed air out of the line with the bleed screw?

    Is it an early pump (28-30) or the later 31 pump?

  • 26 Sep 2017 10:30 AM
    Reply # 5280039 on 5279183

    I never tried a clear plastic tube as a feed tube, funny enough never thought about it. Interesting, must try that!

  • 27 Sep 2017 5:17 PM
    Reply # 5283162 on 5279183

    Thanks for respond, I will tighten the hose (both ends)  and I know rubber tubing is not a good idea no matter how tight. The line has not been touched for two months with oil in tank. In the beginning it had a big pocket of air at the top of the hose where it connects to tank.That air pocket eventually went away. No bubbles till the motor runs. The pump is a 1931 pump and I am going to put it in lathe and get the oil flow amount as George suggest but for now I drain oil every 10 miles ( my round trip for the day) and pump  in fresh oil every time. I also measure the amount and look at the color of it also.It usually is 2.5 - 3.5 oz. every time.I change the  adjusting screw on pump some times to see if I can have the proper amount in crank case when I drain it . I don't have a cable hooked to pump maybe thats a issue. It doesn't leak a abnormal amount of oil when it sets.


  • 27 Sep 2017 11:33 PM
    Reply # 5283411 on 5279183
    Tim Raindle (Administrator)

    Conrad, do you have nuts and soldered tails either end with the pipe in between ? Drain screw for bleeding, all other threads on pump ptfe tape or liquid. Does the pump leak oil itself ?  Check left hand thread end cap, they often leak a little from there, the screwdriver slot is often milled near enough thru the cap, its concave on the inside.If bubbles in the line, its the top joint leaking if you have a full tank of oil that has settled out.

    Welcome to the world of proper motorcycles, why put a car engine in a bike frame :)  ?


  • 02 Oct 2017 6:10 AM
    Reply # 5290557 on 5279183


       Thanks for information! And everyone else also. I will  check all that is mentioned

    I am tightening hose on threads both ends. I will continue to find all the  possibilities that I can figure out. I have a spare pump that I can use to understand all that's involved. I really like this forum we  have for club member's.

       Thanks Again,


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