B&S 18.5 Difficult to Start and Blows Smoke

panabiker · Jul 31, 2011

When I tried to use my Troybilt rider yesterday, it wouldn't start and I had to jump start it. It then ran very rough with a lot of white smoke for a few seconds and stopped. I can repeat it again and again with same behavior. Also, the oil dip stick smells gasoline.
The mower worked fine the last time I used it about 10 days ago. I do change oil and filter at end of every cutting season and check oil level regularly. My lawn is about 1/2 acres so I don't think I over taxed the mower. Is the engine blown, or is there a simple fix? Thanks for any tips.

wildbill · Jul 31, 2011

The mower is fine. What has happened, most likely, is that the float needle in the carb is not seating and the gas has flooded into the engine. I just had one, a B&S 16 hp, have the same thing happen except it would not even start. So, do the following:
1- If you can clamp off or turn off the gas to the carb, do so. If not, drain out the gas tank.
2- Remove the air filter and air filter holder.
3- Remove the carb. If you are not familiar with this, take a couple pics as you go. Also mark where the choke lever, throttle lever, and throttle return spring goes. I still use a paint pen even though I've done it a zillion times...... just a habit.
4- Remove the float bowel. The float and the needle is removed by pulling out a small pin. Clean, use a carb cleaner bought from an auto parts store.
5- Use a piece of tie wire to clean out all the orifices. Take your time. Spray carb cleaner in every orifice and blow them out.
6- Reassemble. You have spent less that an hour and saved a lot of service cash. :thumbsup:

wildbill · Jul 31, 2011

Oh, I forgot to tell you that after you have fixed the flooding problem, change the oil and filter. Pull the spark plug out and crank the motor over for about 5 seconds. This will push out most of any gas that may still be in the cylinder and/or intake port.

panabiker · Jul 31, 2011

Thanks wildbill, I will try to do what you said in day or two and report back.

ILENGINE · Jul 31, 2011

wildbill said:
Oh, I forgot to tell you that after you have fixed the flooding problem, change the oil and filter. Pull the spark plug out and crank the motor over for about 5 seconds. This will push out most of any gas that may still be in the cylinder and/or intake port.

DO NOT AND I REPEAT DO NOT CRANK THE ENGINE TO EXPEL THE GAS!

Ok i will tell you a story about cranking an engine with gas in the cylinder. Had a rider on my utility trailer that had a problem with what is call float bounce. that is when the float bounces from the bumps in the road causing the engine to float from carb overflow. Pulled the spark plug and put it in my pocket. Gas ran out of the cylinder and onto my trailer as wel as the front of the rider. got on the rider and sit on the seat to crank the engine ( now remember the spark plug is in my pocket. the first crank sprayed more fuel the second crank spit more fuel and the third crank lit it. If not for the fire extenquisher that I carry in my truck would of lost the rider and the trailer that day. always use compressed air or remove the plug and let set to dry out, do not crank.

reddragon · Jul 31, 2011

if you had to jump it...then you have battery problems......charge it or replace it first...is this a twin or single cyl?........and is it a manual or auto choke?

panabiker · Jul 31, 2011

reddragon said:
if you had to jump it...then you have battery problems......charge it or replace it first...is this a twin or single cyl?........and is it a manual or auto choke?

Actually, the battery is 2 months old. I had difficulty to star earlier in the spring so I replaced the battery and I kept battery charged with a float charger. The engine is a single cylinder, manual choke.

jross · Jul 31, 2011

I install an inline shutoff valve in any gas line I have on our equipment. Costs 5 bucks. My biggest problem is remembering to turn them on after the equipment dies from no gas.

reddragon · Jul 31, 2011

i just rebuilt the carb on my 2004 troy bilt bronco with the 18.5 briggs single...the float needle was stuck and it broke the tab on the float...check out "my $250 bronco" thread:thumbsup:

reddragon · Jul 31, 2011

i love those shut off valves!......well worth it! :thumbsup:

B&S 18.5 Difficult to Start and Blows Smoke

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panabiker

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ILENGINE

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reddragon

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