D4-7U Issues

u got to much oil in it, (1 1/4 qt max) or big time compression getting into crank case. good luck.

Hi HF,
as ag-mike suggested, the oil level is likely too high and, diluted by gas, in the sump.
If the pony is stopped by turning off the Magneto Switch and forgetting to close off the fuel/gas taps movement of the machine causes the carby float/needle to jiggle on its seat and gas floods in to the cylinders and dilutes the pony oil.

Thin diluted high levelled oil will then cause the dipstick to eject and oil to issue from the exhaust as the oil control rings cannot cope with the thinned oil.
Drain and refill the pony sump with fresh oil to the correct level.

It is importaint to only ever stop the pony--unless in an emergency--by shutting the gas taps and allowing the pony to stop by running out of gas.
This method of shutting down the pony stops all of the above occuring as well as allowing fresh gas to be in the carby bowl for the next start.
Any gas remaining in the bowl also causes needle and seat wear as the components jiggle about during operation.
The remaining gas also evaporates off the light fractions of the gas leaving a stale oily hard to fire mess in the bowl.----especially with today's cruddy gas.

Hope this helps.
Cheers,
Eddie B.