Motorcycles, Snowmobiles, Go-Carts, ATV's and Golf Carts - 2.5 HP briggs recoil starter problem

My 2.5 Hp Briggs and Stratton motor runs great - but when the motor dies at low rpms, it seems to backfire slightly and tear the starter handle off the rope. I have incresed the idle speed, also I have checked the point gap, and it is fine - I think the timing is preset and can't be changed. Also I have disassembled the recoil mechanism and no obvious thing is wrong (There is just 5 steel balls in where 6 would go, but I can't see how that would make it do what it is doing) Any idea what could be wrong? - I bought the motor on a rotatiller, am now using it on a fun cart for my boy - it has torn off the handle 20 times so far in 20 starts! Needless to say, this is a pain. HELP!!!!

There should be 6 balls..... sounds like someone went into it before..... Clean up the bore on the square part the pulley goes onto, and the end of the crank there..... just generally clean it up....
How do the balls look anyway? no flat spots? I don't think missing a ball would affect it....

The part that is driven by the recoil pully has 5 catchy deals on it that are designed to allow the balls to catch one way/release the other way, so I too fail to see how 5 balls instead of 6 is a issue - I tried to reduce the number of balls to only 3 and the same thing resulted; only the engagement - starting part -was not as quick to engage as before. I found no problems (roughness, flat spots on balls, wear etc.) with the catchy thing/balls/ball channels/etc. so I am thinking that the problem is elsewhere. It is frustrating to be having a good time with the boy and then the engine coughs and you find the handle laying on the ground neatly sheared off the rope where it enters the handle! Thanks for your help!

Hi, This sounds like a definite engine timimg problem. Pull the flywheel and check the key and keyways on the flywheel and the crankshaft. Make sure the key fits tight on both the crankshaft keyway and the flywheel keyway. Make sure the key is not bent. All of these could could put the engine out of time enough to cause the problems you posted. You might find the key is broken and the flywheel turned on the crankshaft. The problem is not with the steel balls. I would put the ones you removed back in.
Best regards, Jeff Z.

Would think being a gocart engine, the key would be ok, but re reading your post it came off a tiller.... so it could have caught something from the previous owner..... concur with jeff right now, sounds like at the most.... a barely sheared key.... barely being it'll run, but do the rope trick.

I checked the key and flywheel/crankshaft interface - it is perfect, like new, like designed. So I got creative, and put a spring about 3/4 inch wide/2 1/2 inches long between the recoil rope shroud exit hole and the handle. Tested it last nite and like always, when it is shutoffs (I choke it out to stop it) it will give a little jerk (backfire, I'm thinkin') about 50 % of the time at the end - with the spring the handle is pulled about 1 inch toward the shroud - I've had no more tearing of the handle off the rope!

The older I get and the more I make my own stuff I'm convinced I could have been an engineer!

Thanks for the help - I appreciate the help - this has been driving me nuts!

Just a question - in other mostly larger engines I've had (I'm thinking old vw flat 4 motors from the dinasoar days) , a backfire condition has occasionally been caused by a buildup of combustion byproducts in the combusition chamber leading to a non-electrical firing of the gas/air mixture. Think this is possible? Spark plug is in ok condition, but I never pulled the head and scraped the crud off. I'm wondering if I should try that.

Thanks once again!