How can you get a accurate reading on the raptor? The decompressor will not let mine build up very high?

 

Put a battery chager on & get a full charge in your batt, then put it on boost open the throttle all the way & crank it. Once it gets past a specific rpm the decompressor shuts off. You must have the throttle WFO so it can get air in the cylinder to get a correct reading.

DO NOT CRANK IT A LONG TIME or you can burn out your starter. Also don't leave the charger on boost after your finished cranking it or you'll boil out the acid.

Let me know how it works!

 

Thanks moose that idea has crossed my mind.