Yikes. I think maybe it is something simpler like a leaking intake manifold boot. 550F is a great engine.

 

How worn were your carb boots? I lost an engine due to a hole in the underside of the boot that I couldn’t see and didn’t find in time. Also, if you had low spark, did you change your plugs?

 

@akbrushbuster Ya 550F are great engines never had any issues with them before hoping it's something simple I will check to see if the jntake manifold is leaking.

@subarctic the carb boots were pretty torn up and cracked out, ya I changed both plugs

 

So maybe due to the increase in air to the engine from the cracked boots, it leaned out and toasted a piston or two? That’s what happened to my 550 a year ago.

 

Ya could be, would the compression be affected by worn out piston/rings?

 

I would expect yes, and a gray dust on your spark plug is a sure sign of a toasted piston.

 

If you lost a piston you would have lower compression readings. Your readings are normal.

 

@akbrushbuster Ya 550F are great engines never had any issues with them before hoping it's something simple I will check to see if the jntake manifold is leaking.

@subarctic the carb boots were pretty torn up and cracked out, ya I changed both plugs

If your carb boots (intake manifold boots) are that bad - there is your problem

 

I changed the carb/intake boots when I changed the fuel pump, it’s was the first thing I did.

 

Oh. Your original post was a little unclear about trying to choke it to keep it running? Then sounds like it floods and have to rest the engine for a while.

Could it be your main jet is clogged? Also your specific air temperature and elevation can affect the proper jet size.

 

I can check the main jet again but had the carbs apart 2x so far to clean. I think the jetting is correct I have had the machine going on 3 years and no issue before same location. Do you think the fuel lines running from the pump to the carbs could be clogged or maybe have a pin hole in it causing the issue. I feel like it has to be carb/fuel related as when I cleaned the carbs that’s the only improvement it’s d seen

 

I can check the main jet again but had the carbs apart 2x so far to clean. I think the jetting is correct I have had the machine going on 3 years and no issue before same location. Do you think the fuel lines running from the pump to the carbs could be clogged or maybe have a pin hole in it causing the issue. I feel like it has to be carb/fuel related as when I cleaned the carbs that’s the only improvement it’s d seen

 

Did you check the reeds, none broken or deformed?

 

I have not check the reeds yet. I will plan on doing that

 

Also bad/weakened reeds can make those 550's work terrible, burns more gas and makes the engine sluggish, like worn main jets...same effect

 

meter the spark plug leads and caps , should spec out to like 5 k ohms .

I think the coils and CDI are the same unit , not sure if the coil can be metered .

pick up coil and stator can be metered

Best of luck

 

Update:
The reeds checked out and looked really good like they had been replaced recently. Everything ohm's and looks good on the coils/ignition. I'm really lost here not sure what else it could be. Maybe I'm going down a rabbit hole but would either of these theories make sense:
1) maybe in one the fuel lines leading to the carbs it collapsed internally or there's a small pin hole?

2) maybe the injection oil line is clogged or has a hole not allowing enough oil to be mixed with the fuel causing it to run lean. Or possibly the oil pump is messed up? But when it's running there's no smoke or anything indicating.

I'm at the point now of going back over stuff maybe I bought a bad fuel pump? Or the main fuel line got clogged again.

Thank you everyone all your suggestions and input
Is greatly appreciated, at least I have 5/6 months to get it figured out ????‍♂

 

Did you install a factory new fuel pump?

When the engine is running do you see fuel pumping through the fuel lines?

 

Ya oem fuel pump, fuel is moving through the lines as far as I can tell

 

What about a crank seal

one behind the clutch ? Also check to see if the exhaust pipe got wacked and flattened

 

You mentioned you cleaned the carbs, then it ran great again, but slowly got worse?

Have you pulled the carbs apart and cleaned everything? Some dirt floating around?

My moneys on the carbs.

 

Could the fuel pickup in the tank be clogged? I had that happen on my 380 Skandic.

 

I have not check the crank seal yet I will plan on doing that, I did check the exhaust it was bent it alittle bit I straightened it out. I have not cleaned the carbs a 3rd time yet but I pulled them off and will clean them again I could see it being something to do with them as well since that was the only change I saw in the machine was after I cleaned them. I will also plan on pulling the inline filter and checking the main fuel line I haven't checked it since I replaced it the first time I could see it sucking up some particles.

Also I checked Compression again With a different compression tester than the previous 3 I used.
This time the compression was 145 on one side and 135 on the other side. The previously 3 testers all were 120 no split between cylinders. Is that split enough for a new cylinder pistons?

 

Forgot to mention I took compression with the engine cold throttle wide open. The shop it was at t he guy told me mag side 115 pto 130. Sure is a lot of different numbers with 5 testers being used. I’m not convinced on the compression but could have something to do with it

 

I have not check the crank seal yet I will plan on doing that,?

An easy test is with the engine running spray some wd40 on the pto seal to see if the engine acts/idles differently, if it does then it's sure sign of a leaky seal, normally a leaky seal will make the engine idle faster and eventually run out of gas because the pulse line to the fuel pump is not being pressurized enough to pump gas into the carbs