What thread is this

  1. Kram

    Kram Member

    Messages:
    1,430
    Location:
    Sussex
    Oil filler cap for the bike. Pitch looks 2.5mm, but it could be 10tpi, only 3 turns and it is plastic.

    OD measures 18.6mm.
    Going to make a funnel adaptor as filling is a pain.
     
  2. Paul in Wiltshire Member

    Messages:
    58
    Location:
    UK Wiltshire
    If the bike is Japanese it will be a metric pitch. Hondas are M20x2.5. Existing cap may be loose on the thread as the sealing is by o-ring.
     
  3. cheb Member

    Messages:
    946
    Location:
    Outer Hebrides
    What make is the bike? Honda stationary engines had the same thread as their smaller bikes and some stationary engines had extended filler pipes. Might be worth checking it's not BSP, or that a BSP thread will fit well enough for filling.

    I used to cut the fillers from dead engines and low temperature solder them into BMW airhead rocker covers to be sold to those who wouldn't pay Touratech prices.
     
    Shox Dr likes this.
Advertisements