Engine Help!!

[mokeybozo]

I have a 2009 Yardman 12.5 hp mower. The piston connecting rod went out. Ordered the parts needed off the B&S site. Replaced the rod, set timing on valves, but, cannot get it to crank. It turns over strong, just won't fire. I get a "poof" out of carb about every 10-15 rotations. Any Ideas?

 

[EngineMan]

" "poof" out of carb " did you do anything with the timing..?

 

[mokeybozo]

Well I synchronized the crankshaft and camshaft via this pic from B&S.. is there something else? I must admit I've been out of the home repair biz for quit sometime. I am mechanical but not educated and my brain gets in the way at times.

 

[ILENGINE]

Possibly a sheared flywheel key. You didn't say if you had removed flywheel when doing other repairs. If you did remove flywheel while repairing, if flywheel is not properly retorqued it will shear the key.

 

[mokeybozo]

I did remove the flywheel but it and the key are good. I'm going back in to see if maybe I missed something. one thing though; The valve rods are the same length but the ends are some what different. The rounded ends are pressed onto the rod and one rounded end is longer than the other making the rod shorter than the other (but from end to end - same size). (see attached) Would it matter which valve they go to?

 

[EngineMan]

You should have mark them when you pull them out....!

the intake push rod (lower, aluminum) is hollow and the exhaust push rod (upper, steel) has a red band of paint for identification. but this may not be for your engine because you havn't posted up any numbers, so please check before you put them back in.

 

[ILENGINE]

the aluminun rod goes to the intake valve, which will be the bottom valve on a vertical shaft engine sitting on a rider.

 

[mokeybozo]

OK Thanks. I'm glad I asked because I did not think there was a difference. However, here are the numbers off the motor. Model#219807 Type#2695 Trim# B1 and Code#100105ZA. The first three sets of no#'s are what I used to get my info off the Briggs and Stratton website. Where would I find the info on the Rods? (Just to be sure) Also, when I tore it apart again I realized that I had set the connecting rod for the piston where it first "clicked in", I did not align it with the piston like it should have been. This has been corrected. I'll let you know what happens when I get it back together. Thanks again.

 

[EngineMan]

ILENGINE has given you the right answer in post 7

 

[mokeybozo]

OK I'm back. Had to replace the rocker arm studs because one broke so I just replaced both. Now I still have the same problem. Starter turns it strong but just get blow back from carb. Question; I set the timing just by aligning the crack shaft and cam according to the marks on them, correct? is there something else? I am no mechanic, just like doing things myself. I saw something in another post about adjusting the valves. How would I know if I have adjustable valves? Thanks for any and all help.