good thoughts.....but if the bolts coming out are the problems then why is the brigs block crap as blrcla stated plenty of times....and why did my block break with all the bolts (that i put in ) still tight as could be? i figured the block cracked due to highe compression/strain on the block. What would dual springs that are shimmed do to a motor?

Your bolts came out the first time. Could have put the hairline crack in it then and when adding the additional 3/16" thick bottom along with 1/4" poly with 2000 bolt heads creating drag the motor was just plain being worked too hard with the prop you had. The more you prop a motor and drag it down in rpms the harder it has to work, more strain is put on the parts and it creates more heat. I do not have all of the answers but when you put the Generac and the Briggs side by side opened up the Generac has a thicker, better braced block with large bolts already installed along with two pressure reliefs in the oiling sysem. Dual springs that are shimmed will not do anything to the motor. You were running around 42 pounds of seat pressure which is not much when turning 4500 + rpms. We took care of you anytime you had an issue with the motor and you opted not to do anything else when the block gave out. Again we are sorry for your troubles and the best thing you can do now is leave the duals on there and leave them stock. The End

if i was a smart person i would say if the issue was compression you would see the cracks in the cylinder wall.... and truthfully if you have that much pressure to crack a cylinder the head gasket would give way before the cylinder wall.... (it don't take much wall thickness to hold 300# of pressure, and no that is not a compression number but it is what the cylinder pressure can reach if not more when you get combustion) the major issue with these v-twins is that they are a true 90.... so the natural vibrations of the two cylinders can be identical at a certain RPM... aka resonance and the two vibration signals add and the amplitude goes way up.... you increase the force in the cylinder and the individual signal for each cylinder goes up and therefore resonance goes way up.... add a two blade prop which has again an sinusoidal signal and it can have its on resonance with the motor...

basically what I am saying is you can vibrate the motor to pieces which is what a lot of the issues are caused by....

solutions are a good balanced crank which is hard to get perfect if you static balance which is what most modders do since spin balancing is $$$$$$$$$$$$$... another solution is to add an odd signal in the mix aka a three blade prop... but you still have the motor harmonics to deal with... but it does take one of the resonance RPMs out of the picture...

well that's my spill.... there is more to it as always....

now now mike.. he cant leave them stock.. hes gotta find another flaw in that barge of a tank that he can blame on u and rick some more.. u should know that by now.