Outdoor Power Equipment and Small Engines - Craftsman B&S 6.75hp running speed

Hi,

I have a relatively new Sears mower. I accidently ran it into the fire hydrant in my front yard. The speed was instantly reduced and is much to slow to mow with. I replaced the spark plug thinking it may have been cracked. That did not change anything. Now I am thinking I bent something in the throttle. The throttle speed is fixed but if I pull on the piece of metal that the wire and spring are attached to, I can increase the speed. If I take some pliers to it, how will I know what the "right" speed is? Any ideas?

Thanks for your help,
Lightman

When you say you hit the fire hydrant, did you bend any tin on the engine?? Since you have a briggs, some have an air vane govenor that may be stuck in the dent you made (not likley) but a long shot. If you hit it with the blade, you may have sheared a flywheel key. Don't start bending linkages till we get some more info

Thanks for responding. Only the front of the engine hit the hydrant. What is interesting is that there is not apparent damage. The engine just dropped in RPM drastically and stayed that way. Tomorrow, I will take the mower back out and re-enact the hit to see if I can determine what my have been hit. It was not a hard hit but is was against the cap wrench point of the hydrant.

Thanks,
Kevin

If you post the model # we may be able to find an owners manual and IPL for more reference.
Off hand I cant think of what could have been damaged from the incident you described, but maybe referencing an Illustrated Parts list we could get ya knowledged up on the governor linkage and or adjustment if the throttle is fixed.

Behind the air filter above the carb at the front of the mower is a tab of metal with a hole in it. The tension spring connects to this hole. Bend this tab out away from the engine to increase speed. You want it somewhere close to 3000 rpm. You can try to get it like it was by ear, but the safest way is to use a tachometer.

I re-enacted the fire hydrant incident. It is clear that a part of the throttle must have gotten bent. There is a bracket at the front of the engine that is the anchor point for a spring/wire. The spring/wire adds tension to a control rod that works the carborator. I believe this is what got bent. However, it is not obviously bent. This engine is fixed speed, no throttle speed control. The engine is a Briggs and Stratten 6.75hp #125k02. I guess what I need is if anyone believes that bending the anchor point would change the speed and if possible, what is the design no load RPM. I have an oscilloscope so I can set the RPM by checking the spark pickup.

Any ideas?

Thanks
Kevin

Thanks Cheese...

That is what I was looking for. I just noticed your reply after I reposted.

Thanks again,
Kevin