Briggs and Stratton 550E not starting

[bertsmobile1]

I've just joined up to add to this thread.
Old Sanli mower, with exactly the same symptoms. Starts on full choke, revs, then dies.
Have done all of the checks, cleaned out carb, new plug, etc. No change.
Stripped the motor down to basics, just to check for internal wear and see if the governor teeth are still intact, no problems noted.
Replaced carb with new, no difference.
Mutimetered the coil, all ok. BUT remembered that from a previous problem, the low voltage from a multimeter won't show up any short circuits which cut the spark at higher voltages.
Replaced the coil, runs like a dream now.

As it was,a dead coil or burnt exhaust valve were the only two problems left that were possible culprits.
But turning it over by hand showed compression was fine.

Location: Adelaide, South Australia.
Sanli is a Chinese brand, engine is some Honda clone I believe. Around a quarter of the price of a genuine Honda mower. Great for cheapskates such as myself!
Not popular/available in the states? Not represented on your list of makes.

Ron.

Welcome to the forum.
IF you have a problem with your Sanli it goes in either the Other Brands or Small Engine & Mower Repair with he latter having the most threads .
Sanli makes a lot of mowers for other brands so photos will help the USA members to identify a similar USA branded mower.
Please try to refrain from tacking a differernt problem on the bottom of an existing thread it just gets people confused ,
The techs all use the unread posts search so will see it but some will leave unknown brands for a few days to see if there is some one more familiar with that brand.
If you get no reply after a few days then reply to your own post with a line like "any takers " etc

 

[dhes]

The opposite happens with chokes, actually. The choke plate is 'closed' and blocks most air flow when off, then opens to let air in when warm.

Sorry i got that the wrong way around. I opened up the carb and confirmed the throttle/choke plate is fully open on startup from cold. I checked that the lever arm was not blocked but that seems fine. I used a block of wood (picture2) to close the throttle and tried to start but didnt make any difference. Can someone confirm what position the throttle should be in on these Briggs 550E engines when starting from cold? It doesn't seem right that the throttle stays open at start up.

 

[dhes]

Replaced the coil, runs like a dream now.

Is there any test I can do to confirm it might be a coil issue. Could I remove the blade and spark plug and then attach a drill to the fly wheel and give it a spin. Should I see a relatively constant voltage on the meter?

 

[dhes]

The carb is still suspect. When I was putting one of mine back together, a plastic cylinder shaped object that goes down the throat of the carb came loose, and I had to re-seat it. If you have found any such piece, check to make sure it is in place. Otherwise, if you have access to a known-good carburetor, check it with that.

I have seen that on another YT video where that piece popped out. The main jet goes through it into the carb cylinder. Mine seems to be intact as you can see in picture 1 above. You can see the top of the jet (white bit sticking up) behind it.

I looked up the price of a new carb and would like to rule out all other possibilities before shelling out on something that may not be the problem.

 

[Rivets]

First, if you have to prime the unit there is no choke, don’t use that term as it gets confusing. Second, the throttle should be wide open at startup. The governor will close the throttle when the engine starts. Third, you can remove the spark plug and hold it against the cylinder head while having an assistant pull the starter rope. Best to do this in a dark area, as you are looking for a good spark. SAFETY NOTE. Hold the plug, with the wire attached, with a good pair of insulated pliers. If the coil is good you could get a rude awaking. Also, your assistant should pull the brake bail back, just like when you are cutting. Remember you now have a spinning blade under the deck.

 

[Ron_AU]

Ron.

Welcome to the forum.
IF you have a problem with your Sanli it goes in either the Other Brands or Small Engine & Mower Repair with he latter having the most threads .
Sanli makes a lot of mowers for other brands so photos will help the USA members to identify a similar USA branded mower.
Please try to refrain from tacking a differernt problem on the bottom of an existing thread it just gets people confused ,
The techs all use the unread posts search so will see it but some will leave unknown brands for a few days to see if there is some one more familiar with that brand.
If you get no reply after a few days then reply to your own post with a line like "any takers " etc

Sure. No problem with my mower, all fixed. And I wasn't looking for help with a problem.
The general principle that I brought up applies to fault finding any small 4 stroke engine. If you have checked all the usual causes of not starting or running right, the coil is the next - and possibly last - obvious suspect. Brand of engine doesn't matter so much.

 

[Ron_AU]

Is there any test I can do to confirm it might be a coil issue.

Not without the right test equipment, no.
Try taking the plug out, opening the gap to twice normal, and see if you get a spark spinning up the engine with the plug resting outside the engine on some of the mower metal.
I got a spark from the original coil with the plug out of the engine with the standard gap.
Doesn't mean it fires while under stress inside the engine though. Heat, vibration, arcing across the high tension side of the coil internally, and the engine just cuts out after running for a few seconds, or just refuses to fire up at all.

Anyhow, if you are sure everything is ok - compression, fuel, air - it's the last thing to try. Or put it out on the curb. For me with my old mower, that was a 50:50 line call. Glad I went to the new coil though.

 

[dhes]

*UPDATE*

It's running!!! Well sort off...

I swapped out the spark plug and disconnected the kill switch and got it running for about 10 seconds. It was throwing out quite a bit of black smoke. It cut out and I couldn't get it running again after this and wasnt sure if changing the spark plug or disconnecting the kill switch was the trigger.

So I pulled out the new spark plug and it was wet with with quite a bit of oil. In one of my previous posts I mentioned that the engine was over filled with oil which I removed. I guess this is the remains of the oil overfill.

I cleaned off new spark plug and sprayed carb cleaner directly into the spark plug hole. It still wouldnt start. I then removed new spark plug which again was covered with oily fuel and put back in the old plug which was clean. I connected the kill switch and it fired on the second pull. It's still trhowing out quite a bit of black smoke. It's not running smoothly as seen in video below.

I also pumped the primer bulb when running to see if the revs would increase but it almost cut out.

So I have no idea what was wrong but any suggestion on how to fine tune it from here would be appreciated.

 

[Rivets]

Sounds to me like your cylinder is flooded, caused by the oil overfill. Maybe I shouldn’t do this, but I’m assuming that you drained the old oil and put in fresh. I would remove the plug and pull the engine over 15 times toget as much fuel/oil mixture out of the cylinder. Clean your best plug with carb cleaner and install. Start the engine and let it run. It will probably throw a lot of smoke out the muffler, the muffler may even drip oil, which should clear up in about 5 minutes. You have a lot of fuel and oil to get out of the cylinder, be patient. Do this in a wide open area and you won’t have mosquitoes until May.

 

[dhes]

Thanks I will try that. I didn't drain all the old oil out at the time. I just took enough out to bring it down to proper level. Will change it now that i know the mower is worth saving.