# B&S 5hp RPM not steady and pops



## Erik (Jan 11, 2004)

Holy Cow! I did a search on small engine forums and saw in the description that Hankster was the moderator and knew this was the one for me! Is there anything you don't know about Hankster?

The Caravan is OK - I know very little about lawn equipment engines and have two giving me trouble right now.

This is about my Sears tiller with a 5hp B&S engine. The engine RPMs continuously cycle up and down. It's most obvious when the tiller is sitting and just idling - doesn't matter what the engine speed is set at, it cycles up and down at slow or fast idle. When the drive and tines are engaged and it's under load it's not quite as obvious, however once it warms up, there is a popping from the muffler. More pronounced when not under load. There also seems to be oil sludge coming out from under the top engine cover. Is there some sort of breather under there?

I've cleaned the air filter and the idle issue continues.

Sometimes the rope pull doesn't engage. I have to reach in with a finger and spin the disc with all the holes a little and then it engages on the next pull. Any ideas?

Thanks a lot everyone.
Next I need to ask about my B&S lawn tractor motor.


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## dgraham225 (Dec 6, 2002)

that varying idle and popping is either water in the tank or the small screen on the carb's pickup tube is being blocked. the reason it pops is mostly likely water though. the oil that i assume is coming from under the head could be a leaking head gasket. does the engine seem to have low compression? if so, try removing the head bolts and checking the gasket for leaks. if you do take the head off, go ahead and replace it whether it was leaking or not. torque the bolts back down to 100 in. lbs. or snug to tight with a regular socket wrench. when you do put the bolts back in, hand tighten them all and start tightening them on an opposing pattern.

if that doesnt solve your problem, try replacing the diaphragm pump gasket. after time, that gasket shrinks, causing some pretty strange idling problems. it shrinks even faster when you have to crank it with an additive like carb cleaner or starting fluid. NEVER use them unless you have to.

hope this helps.

Danny


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## Papamerkle (Oct 4, 2002)

How old is the gas? If it's more than 2 months old it's junk. If it is drain gas and put in fresh gas with a gas stabilizer in it.


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## mechmowjb (Aug 15, 2002)

*running problem*

reading through this also makes me think of a 5hp fuel tank 1 time I had one with a foam and plastic baffle inside of it and the foam was starting to deterate and suck up into the pickup tube I guess one of the other questions I would have is how old is it and how many hours are on it any idea? does it run excesively hot does the muffler turn red. is it hard starting after it gets warmed up? those would be some of my questions. but also like was stated before the question about the fuel age is very important due to the fuel manfactures not putting the additives in any more and anything older than 60 days starts to varnish up any more thats just my 2 cents worth


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## Erik (Jan 11, 2004)

It's been raining here for several weeks straight so it's been sitting under a tarp since I last wrote. It cleared up a couple days ago and I decided to check it out yesterday. I fired it up and and let it warm up. It ran fine. I adjusted the carb as per the owners booklet. I drove around hauling some wood to the pile and it ran perfect. The fuel in it was fresh. I also always put stabilizer in my mower gas can in case it doesn't get used right away. Good points on the shelf life of said fuel.

We'll see what happens here as I use it more.


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## T-Trim (Nov 5, 2004)

well what is it???


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