# Briggs and Stratton 5.5 hp motor won't start?



## robhenn

Hi all, 

I have a B+S motor in a Yardmachines Rototiller that won't start. It is the 5.5 Hp OHV motor. 

Each year, after being stored for the winter, it always started up within one or two pulls, but this year she wont start. Nothing happens at all, even after pulling many times. 

I took off the float bowl and cleaned it, it had no fuel in it so I put some new/fresh gas in, the fuel "flows" when the fuel line valve is "open", so I'm guessing that fuel is getting into the engine.

I've tried starting it many different ways - choke open/closed, speed full/ part/ minimal, etc. and nothing happens. My next guess is that there is no spark? How do I test to see if there is spark? Are there any other things that I should try/ check?

Thanks for any and all ideas!

Rob


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## K-B

Try priming it with a bit of fresh gas directly into the carburetor throat (remove the air filter to gain access) and see if it will try to start.


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## clowe

you can get a sparkplug tester that plug into the coil wire an plug the tester is bulb like so when you pull to start you will see it light up ,then you know it is firing. Or remove the plug gound it by letting it hang on body an listen for snapping sound has you pull starter rope


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## robhenn

Thanks all for the ideas. I did as K-B suggested, and after a few tries, got her to run. It would only run with the choke on, and after a few minutes I was able to reduce the amount of choke somewhat and still keep her running, but if I shut the choke off all the way it would stall. What do you think I should do next? 

Thanks again for everyone's help!


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## K-B

Well that tells us that it is a fuel related problem, so we can rule out the ignition. It is not getting enough gas, which means there's a blockage somewhere in the carburetor. How did it look when you had the fuel bowl off? Was there "varnish" buildup on the float, etc?


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## 2and4StrokeTech

The metering jets in your carburetor need to be cleaned. But you would be best served by a complete disassemble, cleaning & rebuild of the entire carburetor. If this is beyond your skill or comfort level, I would recommend buying a product called "Mechanic in a Bottle" Myself and my customers have had pretty good luck when using it as directed. You can find it in the Trimmer/chainsaw section at Wal-Mart & Home Depot.


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## CN_Rail

Old gas, old gas. Well,
Empty the gas tank,
Go the the pumps, 
Get some high-test, 
Put that in a jerrycan,
Put that in the engine,
Run it with choke closed,
And this may help clear out some deposits.
You can solve this problem in the future by running the engine dry before storing it for extended periods of time, and also by running it every 30 days.
It your engine needs unleaded gasoline, never put leaded gas in because that will do the engine no good.
Be careful and post again if you have any more trouble.


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## KD5EEJ350

If you do store it with gas probably wanna use a fuel stabilizer.


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## BrotherJim

Maybe starved for gas too. If it's got a fuel filter, I might replace that too. But yeah, carb tear down and clean, the mechanic in a bottle stuff, or you might get lucky and let it run a good while and then find it works without the choke.


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## KD5EEJ350

BrotherJim said:


> Maybe starved for gas too. If it's got a fuel filter, I might replace that too. But yeah, carb tear down and clean, the mechanic in a bottle stuff, or you might get lucky and let it run a good while and then find it works without the choke.



If it were starved, pouring a bit of gas in the carb or palming the carb with breather off would let it start if but for a second.

OP mentioned backfire, but backfire as it popping from exhaust or out of carb?

If carb I would check the valve/valve springs like the other guy said.

But once u have it torn down that much, I would check the cam, I remember old school B/S had a simple 2 lobe cam and I have dealt with plenty of old chevy's with manual fuel pumps to know that a worn cam lobe cam FUBAR the whole operation.


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## rpmp3

maybe a good time to check valve lash, you could do a leack down test maybe Intake isn't closing to get full suction, also with a leak down test checks both valves and head gasket leak.


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## johnewers

I had the same problem. Fuel to bowl, spark, ether start than die. Pulled the carb and cleaned the bowl, checked needle valve, all ok. Re-assembled, still no start. Then noticed small orifices in brass nut holding bowl in place. Orifices were clogged. Cleaned orifices (horizontal and vertical), re-assembled. Turned on fuel supply, started on second pull, though would not run on choke full off. Let it warm up, ran fine, no choke! Good luck! :smile:


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## Basementgeek

Lets hope they got it running as this post is 5 months old 

BG


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