Manifold leak test

I am going to leak test my manifold. Tractor needs choke to run. Is there a possibility of a leak between cylinders 2 and 3 that is internal between the intake and exhaust that will not show in a leak test?
 
Yes it's possible but more likely that type of leak would be due to a casting flaw in the manifold. Is this a new manifold and a new run issue?

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It has the original manifold on it. New gaskets 2 years ago
when I rebuilt the engine. Problem started 5 or 6 years ago.
 
(quoted from post at 08:29:12 07/31/18) It has the original manifold on it. New gaskets 2 years ago
when I rebuilt the engine. Problem started 5 or 6 years ago.
ocus on carb
 
A new carb 2 years ago had no effect on the
problem. Rebuilding the original carb this
week had no effect on the problem. Propane
test did not prove a leak. So I guess I
will continue to run with choke blocked pit
1/2 way.
 
TexasCowboy ,You say the problem started 5 or 6 years ago ,then you rebuilt the engine 2 years ago and it still has the problem after rebuilding it?From what you discribe You need to do a compression test and be sure the valves are seating.Intakes not seating would cause that problem needing to run the choke to keep it running.
 
Took care of those problems when I rebuilt the engine. All four cylinders have between 90 and 95 psi. All valve seats were resurfaced. Gasket surfaces cleaned and polished. Cylinders honed and all new rings. Not my first rodeo.
 
(quoted from post at 19:52:52 07/30/18) I am going to leak test my manifold. Tractor needs choke to run. Is there a possibility of a leak between cylinders 2 and 3 that is internal between the intake and exhaust that will not show in a leak test?
ne could remove the manifold, cut some block off plates to seal up the intake portion of the manifold, with one plate having a fitting for applying pressure and when pressurized, examine for leaks into the exhaust passages of manifold. Holes have been found before.
vqL945P.jpg
 
(quoted from post at 07:29:12 07/31/18) It has the original manifold on it. New gaskets 2 years ago
when I rebuilt the engine. Problem started 5 or 6 years ago.

What do the plugs look like? I have to assume 2 are rich and 2 are lean if the leak is higher then the carb.

Kevin
 

A couple of guys here participate in the sport of rebuilding carbs... I would send one of'em my carb for them to kick around...
 
(quoted from post at 21:33:31 07/31/18)
(quoted from post at 19:33:02 07/31/18)
(quoted from post at 18:09:25 07/31/18)
vqL945P.jpg

nice job of show and tell right there :)
es, he did a nice job.....I just stole it. :)

all is fair in love, war, and plagiarism :D

i thought i knew who i was stealing this line from - but he says it's news to him. therefore, i tell people that *I* have had a saying for decades now, namely:

"Perfect is good enough."
 
Compression test dry all four cylinders 90 - 92 psi.
Wet 120 - 122 psi, so looks like I flubbed the rebuild a couple years ago. I don't have the tools or know how to blueprint this engine nor,apparently, even a simple complete rebuild, so I guess I am stuck with a very old tractor that is never going to run right.
 
(quoted from post at 15:59:39 08/01/18) Compression test dry all four cylinders 90 - 92 psi.
Wet 120 - 122 psi, so looks like I flubbed the rebuild a couple years ago. I don't have the tools or know how to blueprint this engine nor,apparently, even a simple complete rebuild, so I guess I am stuck with a very old tractor that is never going to run right.
ne of our 8Ns has all four cylinders between 80 & 100 dry/warm and has been like that for over a decade (rebuilt 27 years ago), starts good, runs good, a little low on power, but does its chores weekly. I don't worry about it.
 

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