Excessive fuel consumption

[rpaull]

The valve will be opening and closing at the wrong time. It will also not be opening wide enough.
Set the valve lash at 1/4 turn past TDC on the compression stroke.

That makes a little more sense, I've been setting it at top dead center. I'll give to a try in the morning and let you know.

 

[rpaull]

I wonder if you don't have a fuel problem, to where it is running way to rich. It's not quite as likely if you have the Walbro carburetor, but if it has the Nikki, those things are kinda picky what with the fancy o-ring setup.

Thought about that as well but I couldn't find anything wrong. It is a Walbro carb.

 

[rpaull]

Did you put the caps back on the valves ?? They are very easy to get lost ~!~!

Caps are on the valve stems

 

[zman111666]

Ok, this one is a little wild, but what the heck:
Did you check the oil again recently, to make sure the level hasn't risen? If suddenly you have more oil than you put in it, that would be gas leaking passed the carb, into the combustion chamber, passed the rings, and into the oil. It would explain the increased consumption, odd running, blow-by (too much pressure in the crankcase gotta come out somewhere) and hard starting. Once it gets to a certain point, the cylinder will become hydrolocked and not want to go at all. Did you try cranking without the plug in? Does it blow out a lot of gas if you do?
Another vague possibility: Is it possible something went wrong when you put on the new piston rings, (missing ring, spaces not staggered, etc) causing too much blow-by there, and increased crankcase pressure? A compression test might help determine either that or a valve not seating.

 

[rpaull]

The valve will be opening and closing at the wrong time. It will also not be opening wide enough.
Set the valve lash at 1/4 turn past TDC on the compression stroke.

Worked in it all day trying different lash positions and gaps - was able to get it to run fair by setting the lash at TDC with .004 intake and .006 exhaust still with excessive fuel consumption . The 1/4 past TDC at the same gaps, the motor would not start.
I just don't get it????

 

[Boudreaux In Eunice La.]

Ok Bert and IL Engine have posted on other threads about this before. Head might not be flat and cylinder block might need a stone on it.

I assume you torqued the head to specs.

It almost makes me think that you might be one tooth off on your cam gear if it's not starting 1/4 past TDC.....

Just a thought....

 

[rpaull]

Ok Bert and IL Engine have posted on other threads about this before. Head might not be flat and cylinder block might need a stone on it.

I assume you torqued the head to specs.

It almost makes me think that you might be one tooth off on your cam gear if it's not starting 1/4 past TDC.....

Just a thought....

Yes, I thought about that as well even broke it down again and checked the timing marks and they were spot on - I'm totally lost now!

 

[bertsmobile1]

Double check the valve operations with a pencil down the plug hole while you rotate the engine.
If both the valves are not closed at exactly TDC then the cam is out.
AT TDC there may still be some pressure on the inlet due to the decompressor but the valve must be closed

 

[Tinkerer200]

Did you put the caps back on the valves ?? They are very easy to get lost ~!~!

I am not sure what you think this would affect as long as the clearance is correct. Not all of these engines had caps on the valves according to the Service Manual.

Walt Conner

 

[sgkent]

Is it spitting a mist back out the carb, dribbling, or popping and backfiring? Not to be critical, what are the cam timing marks on your engine, and were they clearly marked, and meshed?