550 wont start..HELP!

[nshalaby]

My buddy has a 550 that wont start. We tried cleaning carb, changing spark plug wires, changing spark plugs, checking starter, and changing fuel. The engine roles over like normal but its almost as if its not getting the spark after the spark plugs are mounted in the head. The compression in the head is normal, and were running out of ideas. Please help if you have any ideas. thanks

 

[ger87410]

Are you sure you're getting spark to the plugs? U can see spark when the engine's turning over and the plug's out?

What happens when you dump a little gas into the carb?

 

[nshalaby]

Yes hes getting a spark for sure and he dropped gas into the carb and also cylinder heads, and still nothing. We dont know if there is something in the enigne thats preventing the engine to start or what.

 

[killaassasin]

fuel, air, and spark

you're sure you're getting spark?
try giving it a shot of ether maybe.
not getting enough air maybe?

 

[ger87410]

There's only 3 things you need to run:
Fuel/air mixture
compression
And spark.


What's your compression look like?

 

[Mouthfulloflake]

you have to have spark at the correct time as well.

maybe check and see if the flywheel key is sheared.

you would likely hear backfiring and popping if that were the case though.

My guess is your spark is too weak, and diminishes under compression.

 

[nshalaby]

How would he check to see if the fuel air mixture is right? He is running dual cooling righ now too with a flow control valve. The thing is he didnt change anything from last year and it was running all last year. He didnt get it winterized, just kept it in heated storage. There was the gas/oil left in the tank though.

 

[ger87410]

Don't worry about the fuel/air mixture if it ran last year and it's not running now and you didn't change anything.

What's the compression?

 

[killaassasin]

If he didn't winterize it, theres a chance that some "gunk" has built up in the carb as well.

 

[ger87410]

If he didn't winterize it, theres a chance that some "gunk" has built up in the carb as well.

Yeah, but he said he dumped fuel into the carb and the cylinders with the same result...

 

[Wolf Child]

have you tried pouring a little fuel into the hull and tossing a match in it?

I have 2 550s in my garage that WILL NOT start this year. the motors turn over by hand but the starters wil not move.

 

[nshalaby]

So it might be a bad starter? He said that he checked that but i dont know exactly. Compression is good. He did take out the spark plugs and dry fired it and a bunch of this dark gunk came out of it and also out of the pisser on the side thats connected to the top of the pipe.

 

[Mouthfulloflake]

so when you said the engine rolls over as normal in the first post, what did you mean?

I took that to mean the starter was spinning it just fine.

I think youve left out too many details for us to be able to offer much help.

 

[sneaky]

so did we establish what the compression is?!