Fouling 304

[tsm1@domain.elided (Tom Mandera)]

OK, aside from pretzeling the driveshaft and cracking the Dana 20 in two...

The weekend started off with a drive from Helena to Missoula.  Prior to
leaving, I showed my step-dad the plugs from the 304.

His determination (better n' mine) is that 6 cylinders are running lean, and
that #5&#6 are carbon fouled - way too rich.  Overall, the motor's running
rich.  I can rev the engine, let it come back down, then blip the throttle,
and it'll blow black smoke rings out the pipes... I'm also leaving carbon
deposits in the grass... ;)

His guess was stuck lifters.  A few ideas followed:

#5&#6 exhaust isn't fully opening.  In town, low RPM, not such an issue..
but on the highway, it's just not breathing.

The other cylinders are not opening the intakes sufficiently, causing them
to run lean.

Sound like a good explanation?  Bent rods on opposite sides of the motor are
not such a common occurrance...

Before I left for Missoula, we drained a quart of oil (just drain the front
hump of the pan - works great) and replaced it with some ATF in an effort to
clean the lifters if that's the issue.

I'm hoping that it just didn't work in well enough prior to fouling the
plugs out on the way over....    I finished the drive on a 6cyl, getting
5mpg (good thing I stopped for fuel halfway), and hitting 70 to 75mph... 

Reading the IH shop manual last night, it sounds like stuck valves could be
the culprit as well or in addition to bad lifters.

Dan mentioned that the 304 had always fouled #5 & #6 when he had it.... I
don't remember doing this since I bought it and drove the '72... hmm..

So, after I get the transfer case swapped in, and the Scout home tomorrow
(or late tonight)....

I pull the valve covers and take a peek (haven't done that on this motor yet)..

Put a wrench on the crank and turn it over a few times and watch the rockers??

Will I be able to tell if the valves are sticking just by watching under the
valve covers?  Or would more disassembly be required?

If they are sticking... what's my course of action?  Yank the heads and take
'em to a machine shop to have 'em ground and install new valves... I imagine
if they've been sticking for a while, they've probably been damaged as well.

Time to put insurance on the Luv pickup again... this might take a while.

-Tom Mandera, Helena MT
http://www.tmcom.com/~tsm1/scout
'72 and '77 Scout IIs