I posted earlier this week about the push rods. Well we have all of the parts put onto the short block and tried to crank it over but no go. I pulled the spark pug and it seems to be getting spark as when I bring it near metal it arcs. It also seems like I am getting gas as I can see some in the carb when looking down through the air port. I took the valve cover off and they are moving when I try to turn it over.

Any ideas would be greatly appreciated.

Did you set the valve clearances on all of the valves?

What did you set the valve clearances at?

Not sure what that is or how to do it.I just took the old head off (including the valves) and put them on the new short block. I just assumed that everything from the old engine would be fine. Can you give me direction on how to do this?

Thanks

A bit more information. After thinking about it a bit more I did have to back off one of the rocker arms in order to get the push rod in place.

The engine is

Model 31Q777 or 31O777 and Model is 0215E1

Thanks

Went to the briggs and stratton web site an figured out how to adjust the valve clearances. Did that but the problem is when I do it the rocker arm nut(?) is loose. Anyway went ahead but it still didnt start. When I hadn't adjusted them properley (actually in reverse) I could get the engine to backfire and really give a loud pop.

Not sure what to do now

Backfiring huh...Really sounds like a timing issue to me, are you sure you adjusted both valves on each cylinder while the corresponding piston was at 1/4 past TDC on the compression stroke? When you adjust the rocker arm nuts there are screw retainers inside the nut itself, I believe they are star head screws but they need to be tightened after adjustment.

Re-check the valve clearances at 1/4" past tdc as described in previous post.

What did you set the valves at?

Check the flywheel and make sure the key is still good.

Hey Guys: Thanks for the help. I did recheck the gaps via the B&S site. The Intake is .076-.127 mm and I set it at .11mm. The exhaust is .13-.17 and I set it at .15. I did mange to see the hew screws and was able to tighten them down so the the nuts on the rockers were tight after I set it. After doing that it sounded like it was trying but wouldnt quite kick over. Then with a little manual playing with the gas and governor on the carburator I can from time to time get a loud explosion and flame shooting out tof the muffler, oops!!!!!! My dog wasnt very happy about that :). So is it a timing issue and if it is can you point me in the right direction for how to set it.

Thanks agin for the help, I sure am learning lots.

Check the flywheel key, make sure it is not sheared. If you installed a new short block the valve timing should be correct as the camshaft is set at the factory. Make sure the igniton module is installed correctly (not upside down) it will have printing on it to properly orientation.

Thanks for the ideas. the key is good and unfortunately the ignition module is in the right orientation. I was really hoping it was one of those. Not sure what to do now. I may be defeated and have to take it in unless you can think of any other ideas for me to try.

thanks again

Something else you might check, I just ran across this today on a job and it happens so seldom that I never give it much thought.

Make sure both valves are opening and closing all the way. I just checked out an engine that would start and run, but was blowing exhaust back out of the carburetor. Turns out that the camshaft is bad and the exhaust valve is not opening much at all.

30 year: Thanks for all of your help. Well I got the mower going, sort of. After checking the key once again, it was actually sheared in half. It looked like it was in place last time i looked but I belive it musy have been an optical illusion of some sort. Also, the gap on the ignition module wasnt correct. Once I put a new key in and got the gap correct i was able to get the mower started. The problem now is to keep it running. It isnt running smooth at all and when i try to increase the gas it chokes out. I think i need to adjust the carb or what i may do is get a rebuild kit for it just to be on the safe side. One quick question. Is there any tricks to set up the internal (static) governor.

Thanks so much for all of your help.

Well there is no trick that I know of, but the governor needs to be set if the arm was removed or installed on a new short block.

To adjust the governor on any engine, loosen the arm that attaches to the governor, hold the throttle at the wide open position and then rotate the governor shaft in the direction that also open the throttle valve to wot position until the shaft stops. Holding the shaft in this position, tighten the governor arm back onto the governor shaft. Thats the static adjustment for a mechanical governor setup on any of these small gasoline engines.

:thumbsup: