New B&S 16HP Dies without reason

[shorty]

Hi All,

I put a new B&S 16 HP in my '93 Max IV last year. It ran like a charm all summer and fall. This spring, i changed filters, plugs, etc. It started no problem and ran real sweet. Then on the first weekend out, it just died for no reason. It would run for maybe 45 mins, then just cut out. Once it cooled, it would restart and usually run for another while before dieing.

I took it in and had it checked out. Mechanic said carb was fine; said he thought it might be the coils. He ran it for 2hrs without problem. Next weekend out, it died and would not come back to life. no spark, no turn over at all. Had to push, lift and winch it a 1/4 mile during the hottest weekend of the year!

I took it into a B&S dealer and told him to check the coils. He ran it for 6 hrs without a problem. Now I have to go pick it up and pay him.

Anybody got any ideas? Is there a way to test the coils? I go deep bush; it doesn't work and I am SOL.

[Mike]

I know your mechanic said that the carb was fine but sometimes you can get some trash buildup in the bottom port under the float. It can be a clear glue like film from gas sitting that is hard to see. It will sporadically block the port so that sometimes it runs fine and others it doesn't. While it may be something else it would definitely be worth removing the top of the carb, pulling the float out, drying all of the gas out and then spraying some carb cleaner though all of the jets / ports to make sure that they are clear and free. I have seen this happen on three different B&S carbs now and it's now one of the first things I do when trouble shooting.

May be worth a shot?

[LarryW]

I now you said no spark but want to comment of the fuel part. Droplets of water are weird in gas. They can block ports and passages. The whole water vs oil thing I guess.

How much are coils? After spending all the money on the shops maybe it would be worth it to just swap the coils out? Assuming they are not crazy high which maybe they are?

Another possibility is the wiring may be bad and short out sometimes. I would find out what wire grounds the coil out and disconnect it right at engine next time it does quit. That would give you something to look into or to eliminate depending on results.

[Roger S]

First I would diagnose for sure whether it's fuel or spark. Both coils aren't going to fail/revive simotaneously. There is that diode wire hooked between them that causes problems. But I'm betting on fuel issues.

Seem like I read briggs has a lifetime warranty on it's magnetron ignition.

[Malee]

Hi All,

no turn over at all.

Do you mean it wouldnt fire up or absolutly nothing like starter motor not engaging.

It would be unusual for the coils to be affected by oveheating. Sometimes if fuel lines or carby can suffer from vapourisation, your fuel actualy boils & vapourises before it runs through your carb jet. it will come good when it cools. check your fuel line isnt running to close to exhaust or engine block. Under easy running conditions in a workshop the tempreture may not get to this level.

Fuel tank breather, pop your fuel cap off make sure it isnt suffering suction problems.

Take some spare fuel or your countries equivealent of start ya bastard. give it a squirt down the carb when it happens, not bang = no spark

[shorty]

Thanks, everyone, for the replies and suggestions. I'll head to Timmins Saturday and bring it home. Once i have it here, I can start following up on the suggestions. I'm leaning towards an electrical problem over fuel though. It starts, runs great, then dies suddenly. When she's dead, there is absolutely no spark at the plugs. The last time it happened, I pushed it out of the bush 3 days after it died. each day i tried it, but it wouldn't show any sign of life. I mean dead - no starter, no whirring, nothing. Then it gets to the shop and bang! starts and runs like a kitten. But the shop ain't the real world....

I checked with the mechanic who looked at the carb. He found exactly what Mike described. Cleaned it up and again no problem starting. He also checked the But next ride out, it left me standing on the side of the trail.
I 'll dig out the engine manual, and will look for other potential shorts in the coil area. I'll let you know what I find....someday, someone else is going to have this problem too, so its better if we get some answers lined up now.

[truckndiesl]

lol @ Malee start ya bastard did u check your engine ground. that what iit sounds like to me. if it wont crank and no where for the spark to get to ground than it wont run.

[Roger S]

If you are sure it has no spark, there's a couple of tests.

one would be to disconnect the ground wire from the ignition, where it connects to the engine cover

the other would be to take the engine cowling off, and remove the wire and diode assy from the coils (part of the kill circuit)

do a search of this site about "diode" for more info.

[Malee]

dead - no starter, no whirring, nothing. .

Correct me if I missunderstand your message (to me it reads ) Your starter isn't working, flywheel not turning there are no revolutions whatsoever?

If that is the case the above posts are way off.

Start Ya Bastard. I have a can for cranking up an old tractor (great stuff)
http://www.google.com.au/imgres?imgu...26tbs%3Disch:1

[Roger S]

Yeah I read that too, and if all his non start problems are like that, fuel and spark have nothing to do with it.