Exhaust blowing out of carb?

[reddogdan]

I have a 5hp tecumseh on a john deere riding mower. Is there supposed to be air blowing out of the carb? As you pull the rope, you can feel it suck, but as soon as it starts, it blows out of the carb and muffler at the same time. Is this right?

Thanks for the help

Danny

[Unregistered]

That's not supposed to happen. Sounds pretty classic for an intake valve stuck open for one reason or another. Perhaps a broken intake valve spring or a chunk busted off the rim of the intake valve. Tecumseh on a Deere? Are you sure?

[Unregistered]

Well, the guy I bought it from said it was a Tecumseh. It doesn't actually say on it. It has a John Deere emblem on the back of the engine. The mower is a model 65. I can't find much information for the year model. Does the blow back from the carb cause a loss in HP?

[Wgoodrich]

5 hp motor tells me that you only have one cylinder. This would tell me you can not have a stuck valve and have the engine start and run.

I suggest you have an engine in need of a valve job yes but I suspect the valves are just worn and need to be ground. This should be a minor repair. If you do the repair ask for a tune up if you have an older engine with points and condenser.

I suspect the blow back is in need of a valve grinding project being minor.

Good Luck

Wg

[Jeff194307]

I agree completely that valves, specifically intake are the cause. Are you sure about the h.p. rating here, this sounds awfly low for a rider, and I have heard and seen both briggs and kohlers on these, but never a tecumseh. Any way, what you will need to do is grind both the seat and valve in order to get the proper seal. If you do not have the seat grinder, it would be best to take it to a small engine shop because the seat grinder costs 200 to 300 dollars.

[Unregistered]

Yes, it is a Tecumseh. Can you tell what hp by the model number? It doesn't say on the engine. The guy I bought it from said it was a 5hp. What would a small engine shop charge for a valve job? I only have $130.00 and an old rider mower that I traded in for the John Deere. Can someone explain to me why and how it runs with that much air coming thru the carb? It seems like it would never get fuel.

Thank for all your help.

Danny