More questions......

[CODI]

Okay. So the carburetor seems to be good. Could the sputtering be an exhaust valve not seating right? And how does vapor lock occur. The guy here in town seems to think that it is vapor lock that is causing it to not start after it has been working.

I tried to take a video of it sputtering so you all can hear it. But it is really weird, when it goes up a hill or is running the mower it doesn't sputter. But when going down a hill, without the mower running it will sputter. I don't get it....

 

[HCooke]

Park it on a hill and check for gas flow. It is not
vapor lock.

 

[CODI]

(reply to post

When it did it the other day, I opened up the main jet on the carburetor 1/4 of a turn and it hasn't done it since.

I am more concerned about the source of the sputtering than anything at this pointat 23:14:44 04/25/14)

 

[R Geiger]

Running uphill or the mower running requires more power and when you opened up the main jete 1/4 turn you fixed your problem by giving it more fuel.

 

[souNdguy]

vapor lock entails a fuel pump.

a burned exhaust valve would be able to be detected on a comp test as a lower compression that is not helped by oil. probbaly easilly find it with a manifold off too.

 

[R Geiger]

(quoted from post at 07:41:45 04/26/14) Running uphill or the mower running requires more power and when you opened up the main jete 1/4 turn you fixed your problem by giving it more fuel.

looks like I misread the original post. but you may have dislodged something in making the adjustment.

 

[CODI]

I just had this engine apart less than a year ago. What would cause a burnt valve?

 

[R Geiger]

(quoted from post at 11:06:53 04/26/14)
I just had this engine apart less than a year ago. What would cause a burnt valve?

improper valve adjustment can burn them. only a compression test will tell for sure!

 

[CODI]

The compression test will be through the roof right?

 

[CODI]

(quoted from post at 03:37:10 04/26/14)
The compssion test will be through the roof right?

I mowed with it today and it seems that the sputter gets worse as the engine e warms up. I noticed that while even running the mower it doesn't maintain an even RPM. dead cylinder????

 

[Tom N MS]

Sounds like u have a fuel delivery problem..flowing
just enough to be ok sometimes..Maybe float hanging
when u are going down hill. I bet the problem is in
the carburetor, not valves..But, Yes, do the
compression test and report back..Please let us know
what you find-that way we all learn
something..Thanks

 

[G6 at Snook, TX]

Codi,

I still think you are in the area of carburetor issues. These are not complicated as compared to muscle cars of old, but a Marvel carburetor can beguile me from time to time. I recall a Popular Mechanic author saying that those who worked on carburetors were part horse whisperer and rocket scientist. I bet there is still trash in that thing. Take it off and go through it again sometimes it takes multiple trips to the cleaner to get it right. BTW, is it an aftermarket carburetor, if so it is gold or cast iron, or is it a rebuilt Marvel?

As for the compression test, do a dry/wet test and report back the numbers for all four ports. It is not hard nor terribly expensive to perform, and you can do it yourself. I would search for a post from Bruce (VA) of about four years ago when he talked about putting together a simple adapted gauge that works well with the hood in the way. Follow the direction in how to test it. When you report the numbers, plug closest to radiator is #1 and working back from there.

 

[CODI]

I agree. I believe the issue is in the carb. I did however adjust the valves today as they needed a little adjusting. Still sputters though. I will be looking into the carb to see what the issue is. The carb came from TSC. So I guess it would be an after market carb.