Out Of Nowhere P216 Develops An Attitude.

[TNT9848 5]

Hi Folks

i have a 1994 416-8.  I acquired it last Summer.

It has 697 hours on the working meter.  It ran great last summer and until recently.  Last winter, I pulled the heads and “decarbonized” the engine.

Several weeks ago, the plastic in line fuel filter, disintegrated at engine start up.  I attributed it to poor manufacturing.  10 days ago, the new plastic filter did the same thing.  I attributed it to poor manufacturing again and replaced it with a metal fuel filter.  All was good for a few cuttings,  but now the engine runs horribly, (rough with hesitation and no power) after an easy start and a five minutes of operation.  The carburetor continues to “bubble” gas out of the small aperture near the choke plate at the top of the carburetor and white vapor emits from the carburetor after shut down.  This continues until the engine cools down a bit.  The cooling fins are free and clear.

I admit to not being a mechanic.

Any help will be appreciated.

Edited July 18, 2022 by TNT9848

[lynnmor 7,482]

It sounds like you are using some kind of snake oil in the gas or gas that contains too much ethanol.  Many of these additives are powerful solvents that sometimes temporarily dissolve the crud in the fuel system and people think they are great.  My suggestion would be to flush the fuel tank, replace the petcock if needed, replace the fuel line and install yet another fuel filter that is clear like the original.  Hopefully the fuel pump hasn't been damaged.  After that is done,try it but I would bet you have plenty of junk inside the carburetor and it needs to be physically removed.  Use only fresh regular grade gas with no more than 10 percent ethanol.

[oldlineman 1,489]

Or better yet ethanol free, I know it is very dear these days but so are carbs and fuel parts. Bob

[Snoopy11 5,717]

1 hour ago, TNT9848 said:

rough with hesitation and no power

Sounds like those fuel filters came apart and clogged the carburetor. Better get to cleaning...

 

I'd run NAPA fuel filters... or any John Deere filter (they are very good quality)...

 

Don

[Blasterdad 2,796]

 

1 hour ago, lynnmor said:

I would bet you have plenty of junk inside the carburetor and it needs to be physically removed. 

 

This is what you're likely going to find in your carb, this is from the same thing, "disintegrated" fuel filter.

Good 'ol ethanol damage, I use filters with metal screens & rec fuel. Clean out your fuel lines & pump, clean out/ rebuild your carb & you should be good to go..

 

Edited July 18, 2022 by Blasterdad

[TNT9848 5]

Thanks everyone

I it is just a clogged up carburetor.  Would a sticking valve cause similar problems?

[wallfish 17,196]

A clogged up carb will not "disintegrate" 2 fuel filters.

Can you please explain what you mean by "disintegrated"? or better yet post some pics

Where and how long does this white vapor continue to be expelled? Does it have velocity to it like it's pressurized?

[TNT9848 5]

I have thrown the filters (pieces) out.  They cracked, the plastic disintegrated into pieces, and the remaining pieces were very fragile.

The white vapor ascends from the carburetor body, kinda wafting up.

Thanks for your thoughts.

[ineedanother 1,369]

Likely a stuck float. I'm betting the bowl looks a lot like what @Blasterdad showed above. Nothing catastrophic...

[wallfish 17,196]

You will typically see that white vapor in the carb throat when the air filter is off.

I'm with @lynnmor on this. Some kind of snake oil is eating the filters. Or it could be located near too much heat

 

[lynnmor 7,482]

Check to see if your oil level raised a bit, you may have been pumping a considerable amount of fuel thru the dirty carburetor flooding the engine and the white vapor may be coming up from the crankcase.  If you detect the smell of gas on the dipstick, then an immediate carburetor cleaning and oil change is needed. 

[Blasterdad 2,796]

3 hours ago, TNT9848 said:

 Would a sticking valve cause similar problems?

Anything is possible, but with a stuck valve it would either not run at all or backfire like crazy.

I'm 99.9% sure your carb/fuel pump is just full of crud...

[ri702bill 8,758]

While you have the carb apart, check the float if is brass, rattle it and listen - a loose solder ball inside going "Ting-ting" is OK, but if you hear sloshing, it is fuel logged and heavier than it should be. 

You can either attempt to drain it and resolder it, or replace it. Also check the condition of the needle and seat - if questionable, get a carb rebuild kit.

Everything you described is saying that for some reason(s), there is too much fuel in the bowl.