What’s this?

[Exmoor beast]

Solid brass syringe/ plunger. 16mm OD , 87mm long, 15mm plunger stroke, 6mm exit hole and also plunger piston rod.
3 x calibrated rings on plunger rod 3mm apart. Sprung loaded and take 5kg force to move plunger to first calibration.
I found this in a tool kit onboard a grey import Yamaha direct from Japanese home market when I was involved in importing “greys” back in the early nineties. It seems too small for a grease gun, possibly a belt tension device ( but on a chain drive bike?) - I don’t know- What is it and why was a Tokyo biker riding around with it under the seat?

 

[piranha-bro2]

Insulin syringe - he was a diabetic

 

[Legs]

Cam chain tensioner?

 

[Vince]

All good Archaeologists digging that up would say Religious artifact or sex toy.

 

[Exmoor beast]

All good Archaeologists digging that up would say Religious artifact or sex toy.

Or a playing piece from a Viking chess set- I sniffed it, not a sex toy!

 

[Exmoor beast]

Cam chain tensioner?

Some sort of tensioner is feasible - it is bone dry and has never contained grease so I’m guessing grease gun is unlikely.

 

[Legs]

Reckon those rings indicate when the cam chain needs replacing.

 

[Chuck3CL]

Looks like a cam chain tensioner similar to this one, a Kawasaki...

 

[Exmoor beast]

After years of head scratching and internet searches , came across this on American ebay!
It would appear to be a Kawasaki drive belt tension tool- who’d a thunk it?

 

[helicopterjim]

Some kind of retaining plunger.

 

[chrisk]

After years of head scratching and internet searches , came across this on American ebay!
It would appear to be a Kawasaki drive belt tension tool- who’d a thunk it?

Then it could be used for a Lav primary chain tensioner. Drill a hole through the top of the cover. Check tension when static, adjust and put a wine bottle cork in the hole and hey presto, off you go.