Briggs & Stratton V Twin 21Hp OHV Model 407777

[Muggzy]

I’m replacing the piston heads and connecting rods in my Briggs & Stratton V Twin model 407777 motor. I made sure the connecting rods 1 & 2 are facing in the correction direction when installing and securing to the crankshaft. I also made sure when securing the connecting rod caps that they match correctly to the connecting rod by matching up the high marks on each. I’m able to move the crankshaft when I hand tighten the bolts of the connecting rod caps but if I tighten the bolts any more than hand tighten I cannot move the crankshaft.

Is this correct or is something wrong?

Thanks
Bob

 

[ILENGINE]

You didn't accidentally get the .010 undersized rods did you. They won't fit a standard sized crankshaft.

 

[Muggzy]

You didn't accidentally get the .010 undersized rods did you. They won't fit a standard sized crankshaft.

Thank you for your response.

I brought them used, how can I tell, is there any markings to look for?

 

[ILENGINE]

There should be a marking on the rod. Could say 010 or something like that. Also something else the may be relevant is on january 8, 2004 the rod and crankshaft part numbers changed so there could be an issue with crank diameter from that aspect also.

 

[Muggzy]

There should be a marking on the rod. Could say 010 or something like that. Also something else the may be relevant is on january 8, 2004 the rod and crankshaft part numbers changed so there could be an issue with crank diameter from that aspect also.

I checked the rods did not see any markings.

I have a basic question...once I torque the connecting rod cap bolts to specs onto the crankshaft should I be able to turn the crankshaft by hand to move the pistons up & down?

 

[bertsmobile1]

If you lubed the rods before you assembled them the answer is yes.
If you put them on dry the answer is no and there is a better than even chance you will have wrecked the rods
Without the plug in you should be able to turn the engine over with the palm of your hand.