Jeff jet 1750

[Jeff B]

Manual power valve actuation
Be interesting to see what difference it makes.

[Jeff B]

Copper wrapped I big portion of chamber, then wrapped with fiberglass tape, yucky and itchy.
Pre heat rawxwater around exhaust before entering cylinder

[Jeff B]

Started on engine cover/seat. Plenty room.....

[Tones]

How can a belt be rated for a torque?  Surely, that depends totally how many teeth are engaged on the pulleys and the diameter of the pulleys..

By the width of the belt.

[Paul]

By the width of the belt.

That's not relevant. Belt width would just be proportional to breaking tension

Torque is "force x radius". If radius is unknown, then torque is unknown.  If you put the same belt on a larger pulley, it is now capable of more torque tansfer, hence torque rating on a belt alone is meaningless.

[Jeff B]

Used up all my little offcuts of EVA foam, made seat/engine cover.

[Jeff B]

Few more small things to finish then test time.

[Henry]

Good entertainment value, cant wait to see it going.

[steelo]

Inspirational Jeff. Can?t wait to see some action shots or video

[Jeff B]

I'm hoping that when the belt fails it will just rip the teeth off (when the mighty 125 hits power band) rather than shreds the belt right off, that way I should still be able to putter back to boat ramp....

[Paul]

Maybe a snorkel for the carb intake?  It looks pretty close to the sucking up water from the rear corner?

[Jeff B]

Finished off drive setup, used a keyless taper lock on pump shaft. And welded the honda cam pulley to yamaha drive gear engine side.
Belt is tensioned with slot and thread so whole engine moves.
Hope my drive ratio is calculations are accurate....

[Jeff B]

Got sick of waiting for my new Vespa bevel drive starter to turn up so fitted an old Kawasaki starter, just fits.
A kick start or pull start was not going to be too practical

[Jimmy Jet]

I think the power valve will make a huge difference. Years ago I rebuilt the top end on my 93 CR250 and incorrectly re-installed the PV actuation rod. The bike would rev to about mid-range and then just go flat, full boggy.

[Henry]

Starter motor look heavy tho. Half as much as the engine.