Briggs and Stratton Engine Problem

[finiteguy]

I have a 2 year old JD lawn mower with engine problems. Runs rough and hard to start. Any adjustments that I can make? Air filter and spark plug new. Gas is also new.

[dpb]

Ignition, fuel, air are it...beyond that you're talking mechanical damage. Eliminate problem(s) in each of the above.

Which engine, which mower? 2-yr isn't long unless it's been shorted on the maintenance or somehow abused. Older and I'd suspect the traditional carb-to-body connection loose that screws up air mixture by extra air inlet which also has variable symptom as runs owing to the vibration changing the gap. Shouldn't be a problem w/ newer but never hurts to check.

If no joy, there's always Mr Deere to help... :)

[jamesgangnc]

Almost always fuel issues. Sometimes gas evaporates from the carb while it sits for long periods and deposits form. Remove, disassemble, and clean the carb. Make sure the jets are clean. If you see deposits then use a small piece of wire to clean out the main jet. If it's just 2 years old and you are careful you probably will be able to reuse the gaskets.

One way to help prevent deposits from forming is ti shut the gas off and let the engine run until it dies. You don't need to do that during the summer but you should at the end of the year if it's going to sit for the winter.

[mkirsch1]

Do you have the rest of the summer to mess with it and learn about small engines in the process? That's what it's going to take to get it fixed.

If not I suggest you get your mower to the nearest JD lawn/garden equipment dealer for repair ASAP.

You're going to be taking apart things that were never meant to be taken apart, and if you don't have experience with those sorts of things, you could end up with a pile of parts and no idea how to get them back together. God forbid you break something in the process.

There could be any number of things wrong with your mower. First and most common, a dirty or gummed up carburetor. Could be anything, though.

[dpb]

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I keep hearing this but in 50+ something years I've seen the feared gas deposits in the small engine carb exactly -- well, let me count: yes, zero times. Sediment in fuel from contamination, yes; the fuel itself I just don't see it and never do more than close the cutoff in winter storage. Come spring, a spritz of fresh in the carb itself for starting and away she goes; fresh in the tank to top it off will mix in and by time need a refill you're all brand new again for another year.

I don't buy it...if it's a fuel issue it could be but I'll bet it's more of a contamination than otherwise caused. Older leaded gas was somewhat worse because the lead would gum out but unleaded "not so much"...

$0.02, imo, ymmv, etc., etc., etc., ...

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[jamesgangnc]

I've fixed multiple carbs that had deposits inside the jets. Causes a lean condition and make them run rough or surge. Is it just the fuel, or is it the fuel plus contaminants, could be. But with lawn equipment the likelyhood of contaminants in the gas is pretty high. In gravity fed carbs vented to the atmosphere evaporation will just continue all year. Turning off the gas stops that. Running the gas down is even better. It's not a problem with the little diaphram carbs. They don't have a float bowl.

[dpb]

On 7/5/2011 12:42 PM, jamesgangnc wrote: ...

Maybe I'm just lucky... :)

Never had anything w/ anything but standard bowl carb's on any lawn gear (except the two-cycle stuff and it doesn't count anyway what w/ that stinkin' oil in the gas thing... :) ).

But, ime, that's the last thing I ever would look for as a problem; it just hasn't ever been an issue for whatever reason.

As the extreme example (and even I don't recommend this :) ) had a small tiller that when moved from TN back to farm didn't use for about 10 years. It had nothing done to it the fall last used it in TN; just rolled it into the garage and let it sit. Put it on truck as was; unloaded it and put it in shed when got to KS. Decided that the cultivator attachment on it might make wife's gardening a little easier last year so rolled it out. In that time the gas left in the tank had become rather thick ;) but despite taking the carb off and apart, it showed no indications of any problems. Rinsed out tank, blew off the accumulated KS dustbowl dirt of 10 years in not very tight shed and it started right up and runs as well ever...when warm, shut off and changed oil and following that went to work.

Granted, if had realized wasn't going to use it for several seasons at the time I would have drained the tank and done some storage things but my experience is simply that just leaving stuff over winter doesn't lead to any high rate of occurrence of carb clogging/gumming/whatever--just don't see it for whatever reason. I will find a fair amount of sediment in float bowls and empty them but other than that I fill the tank and go for the most part. I can't explain why if that's not a common experience; I'm just following dad (and grandfather) in behavior/treatment.

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[N8N]

what I've had happen several times is on small engines with floats in the carbs to control fuel level in the bowl, similar to an automotive engine, I've had the float stick to the bottom of the bowl and make the engine flood out. I can only hypothesize that this is due to gum/ varnish from the old gas, but usually simply pulling the bowl and cleaning the bowl and float solves the issue.

nate

[dpb]

On 7/5/2011 1:53 PM, N8N wrote: ...

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Guess I'm lucky... :) --only float problems I've experienced have been pinhole leaks have doomed a couple and the float valve jet getting some sediment that keeps from seating or deforms/abrades it enough won't seal. Old '78 Chevy 4x4 was so bad at one time that it ran enough raw gas into the block it flooded the plugs out...took a little head-scratching first symptoms; had never had the event until nearly 65 yr old w/ have lost count the number of vehicles, small and large in that time! :)

Don't believe any of above has been fuel per se or related to the magical properties somehow obtained by letting fuel sit for a few days or months, though; it's almost always sediment either from tanks or simply contaminated.

Yet again, ime, $0.02, ymmv, etc., etc., etc., ..., of course.

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[Ralph Mowery]

It seems that the gas where I live has enough ethenol in it that it will setup. I have a 5 kw generator and before I started putting the Sta-bal in the gas, I had to clean out some green goop in the carborator several times. That was after it set about 6 months without starting. I now start it atleast once a month and it will start on 2 or 3 pulls at the most.

I now put the Sta-bil in all the gas for the small engines and have not had that problem. I bought a tiller two years ago and often use it just in the spring. It usually starts on about 3 or 4 pulls with the old gas in it.

I do not seem to get the sediment problem as the gas cans are plastic and so are most of the tanks.

[dpb]

On 7/5/2011 4:02 PM, Ralph Mowery wrote: ...

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Over 10% ethanol? It's been that here and prior to that in TN for over

10 years and I really can't see a whole lot of difference other than mileage from the lower Btu content.

Green goop sounds like chemical reaction w/ something in the fuel system--is it intended for ethanol? So far, even w/ the very old JD yard equipment (some as early as mid/late-60s, other in mid-70s) I've not seen any problems even though there was no thought whatsoever back then about ethanol and still were intended to run on leaded.

The old grain truck that use as the seed tender any more is a '58 Chevy C60 (tagged for 38M gross for idea) has 283 and still runs "ok". It needs rings and cam but gets the job done so suspect at my age it'll outlast me and whoever gets it at the auction can fix it up... :)

I did use lead-replacement additive in it, but it's become so tough to find so quit a few years ago...

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[clare]

No adjustments, but do yourself 2 favors. First, buy a can od SeaFoam fuel treatment from NAPA, and then run premium shell gas if you can get it - or any other ethanol free fuel.

Follow the instructions on the sea-foam can.

[clare]

Ethanol gas causes the "greenies" in MANY carbs, because it holds water. Worse in mowers that are stored outside or in extremes of temperature and high humidity - but DEFINITELY not uncommon - and no better than in the days of leaded gas.

[clare]

But it is STILL a problem - because it's not JUST evaporation that causes the problem

[jamesgangnc]

I agree, water and ethanol is another problem. It settles out when the amount of water absorbed by the ethanol reaches a certain saturation. Worse with small engines because they sit longer and their fuel systems are more exposed to the atmosphere. I use premium and add stabilizer all year. I'm never sure when I'm going to stop using gas equipment. I run the bowl dry on my generator because it sits longer than anything else.

[dpb]

On 7/5/2011 8:22 PM, [e-mail] wrote: ...

Never seen it for some reason...perhaps because it's pretty dry in SW KS; but that wouldn't explain no problems in E TN (altho there was more no ethanol there at the time, I never really hunted it out)...

Curious...

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[dpb]

On 7/6/2011 7:03 AM, jamesgangnc wrote: ...

Amazing "everybody" else seems to have such troubles and I somehow don't...never had any sign of any "settling out" w/ E10 and all the gas-powered gear (from the smallest 3 hp tiller to two riders to the trucks (the old grain truck sits for months at a time, particularly over winter) to the JLG 40H manlift (Wisconsin air-cooled V4) which also sits for sizable periods.

Just never seems to be an issue w/ fuel/carburetor problems; the C60 truck is a '58 has been on the place since new; it's never had the carb touched in those 53 years and other than replace the fuel filter on (rare) occasion, it's never had any fuel system maintenance (oh, well, yes, I did replace the tank sending unit a few years ago as it had failed, but all that affected was the dash fuel gauge, of course).

I'm still puzzled by why there seems to be so much trouble elsewhere it's the first thing everybody jumps on when there's any problem at all...it really is beyond my ken/experience that fuel/carb is an issue.

The biggest problem I've had w/ small engine carbs is the eventual wearing of the body around the throttle shaft so that excess air srews up mixture or it gets difficult to keep the carb body mounted solid on intake with time which leads to same symptoms/problem. But not trouble w/ jets gumming/floats sticking, etc., that seems to be what other gets commented on most heavily.

Guess it'll just have to remain a mystery... :)

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[clare]

Farm gas, by chance??? MOST is "ethanol free"

[dpb]

On 7/6/2011 8:14 PM, [e-mail] wrote: ...

Nope, even Equity is E10; no local distributor has anything w/o at least E10

[clare]

So far in the USA it is either max E10 oe E85 by law. E15 cannot YET be sold . EPA law.