1996 seadoo xp won't crank with spark plugs in

[Coastiejoe]

If you were to boost the questionable battery with cables from another sea doo battery that was taken out of the machine, shouldn't that give you enough juice to get the starter cranking with the plugs in?

A bad battery is hard to make it a good battery by stacking batteries. For some reason, the bad battery sucks so much from the second battery that it just can't do the job.

 

[Raymond 88]

Ok, that explains things. Not sure why a good battery hooked up with a weak battery doesnt give you more starting power. Some things just cant be explained. I will grab a new battery and install a valve on the oil line. Does anyone know if you can can use a 1/2" plumbing valve that we use on those plastic PEX plumbing pipes?
Thanks for the help