only runs on brake cleaner

[freq432 6]

i have a 414-8 magnum14. My engine only runs on when shooting brake cleaner into the breather and then it dies. new gas, gas line, gas filter, new carb (my 3rd one) mix screws set  top 2 turns, Idle mixture 1 1/4, fuel pump is pumping, fuel bowl is full and I have made several flot adjustments, float isn't leaking, compression is 125 lbs, spark plug is sparking gapped at .025. I can't keep it running unless I spray brake cleaner into the carb. What am I missing?

[Pullstart 62,786]

 @freq432!

 

is the carb clean?  It could be the passage from the bowl to the venturi is clogged...  try removing the air cleaner completely, then covering the carb opening with your hand.  When you roll the engine over a few times it should pull hard enough vacuum to suck debri through the clog if it isn’t too bad.

[Darb1964 1,042]

Not getting fuel, you probably know that??

[freq432 6]

carb is brand new and pump is pumping. bowl is always full

 

[freq432 6]

18 minutes ago, pullstart said:

 @freq432!

 

is the carb clean?  It could be the passage from the bowl to the venturi is clogged...  try removing the air cleaner completely, then covering the carb opening with your hand.  When you roll the engine over a few times it should pull hard enough vacuum to suck debri through the clog if it isn’t too bad.

yeah I have done all that

[Pullstart 62,786]

Did you verify the passage is not full of casting flashing?  I think @ebinmaine has had flashing issues with a new carb or three.  I’ve had good luck with them, but every blind squirrel finds a nut once in a while!

[ebinmaine 67,268]

1 minute ago, pullstart said:

nut

You calling me a nut?

 

 

 

Yeah. I am not exactly what you would call a fan of the cheap replacement carbs.....

 

[freq432 6]

7 minutes ago, pullstart said:

Did you verify the passage is not full of casting flashing?  I think @ebinmaine has had flashing issues with a new carb or three.  I’ve had good luck with them, but every blind squirrel finds a nut once in a while!

so what would casting flashing be? Fragments from when it was casted or perhaps when it was machined? New carb is a cheap one but the one I started out with is one one of the better ones and the box it came in said kohler on it. That carb in particular I took arpart and cleaned with bread tie wire and blew everything out real good and it did exactly what its doing now with the new cheap carb. 

[ebinmaine 67,268]

11 minutes ago, freq432 said:

so what would casting flashing be? Fragments from when it was casted or perhaps when it was machined

That's exactly right...

 

 

if you have two carburetors doing exactly the same thing and one of them was an o e Kohler carb it's possible it is not the carburetor causing the problem.

 

54 minutes ago, pullstart said:

covering the carb opening with your hand.  

 

Have you tried this?

[freq432 6]

1 minute ago, ebinmaine said:

That's exactly right...

 

 

if you have two carburetors doing exactly the same thing and one of them was an o e Kohler carb it's possible it is not the carburetor causing the problem.

 

 

Have you tried this?

Oh yes. several times and on all 3 carbs. Thats the first thing I do before I decide to take them apart and that usually works

[freq432 6]

If its not the carb is it could be an ignition problem? would a weak ignition burn brake cleaner but not gas?

[ebinmaine 67,268]

1 minute ago, freq432 said:

If its not the carb is it could be an ignition problem? would a weak ignition burn brake cleaner but not gas?

I don't have that answer but somebody might be along soon that will.

 

You got a good one there.

I'll be curious to see what solves this.

 

 

[pfrederi 17,663]

When you spray cleaner in you are forcing it into the area of the valve stem.  From your description it sounds like there is either blockage preventing fuel from being pulled up the main jet or insufficient vacuum generated to pull it up and into the valve stem area. You seem to have cleaned it enough that blockage of the main jet shouldn't be a problem. I guess.  Have you checked the intake valve adjustment.  if the valve is set way too loose then valve may not be open enough to draw enough air through the carb to pull fuel up the main jet and into the valve stem area.

 

Is this a new issue or something getting bad over time...

[Pullstart 62,786]

Remove the spark plug, blow it dry or use a lighter to dry it...  replace it and crank it over with the choke closed.  Pull the plug again and see if it’s wet.  By all means, a weak spark or little timing issue could be a problem...

[freq432 6]

1 minute ago, pullstart said:

Remove the spark plug, blow it dry or use a lighter to dry it...  replace it and crank it over with the choke closed.  Pull the plug again and see if it’s wet.  By all means, a weak spark or little timing issue could be a problem...

its wet. The magneto was replaced 3 seasons ago. It was a factory direct part. Gap then was set correctly to flywheel. How would I adjust timing? Youtube doesn't seem to be a very good resource for these older kohlers

[freq432 6]

6 minutes ago, pfrederi said:

When you spray cleaner in you are forcing it into the area of the valve stem.  From your description it sounds like there is either blockage preventing fuel from being pulled up the main jet or insufficient vacuum generated to pull it up and into the valve stem area. You seem to have cleaned it enough that blockage of the main jet shouldn't be a problem. I guess.  Have you checked the intake valve adjustment.  if the valve is set way too loose then valve may not be open enough to draw enough air through the carb to pull fuel up the main jet and into the valve stem area.

 

Is this a new issue or something getting bad over time...

Good point and no I havent checked valve clearance but that does give me some direction

[bds1984 1,429]

If you are using one of the $30 ebay special carbs from China, you may have a cosmoline booger in it.  I have used four of them on 312-8s and my C165 and all work fine now but I have found that they have some crud in them right out of the box.

[pfrederi 17,663]

Service manual may be more reliable than You tube

 

 

 

[Pullstart 62,786]

2 minutes ago, freq432 said:

its wet. The magneto was replaced 3 seasons ago. It was a factory direct part. Gap then was set correctly to flywheel. How would I adjust timing? Youtube doesn't seem to be a very good resource for these older kohlers

 

I only have one Magnum and haven’t even had the tins apart.  @953 nut might you know how timing is set?

[freq432 6]

3 minutes ago, bds1984 said:

If you are using one of the $30 ebay special carbs from China, you may have a cosmoline booger in it.  I have used four of them on 312-8s and my C165 and all work fine now but I have found that they have some crud in them right out of the box.

yeah that makes sence

[freq432 6]

3 minutes ago, pfrederi said:

Service manual may be more reliable than You tube

 

 

 

awesome! thank you for posting this. very helpful

 

[pfrederi 17,663]

3 minutes ago, pullstart said:

 

I only have one Magnum and haven’t even had the tins apart.  @953 nut might you know how timing is set?

  No timing other than making sre air gap is correct.

[freq432 6]

Just now, pfrederi said:

  No timing other than making sre air gap is correct.

copy that

[freq432 6]

Ok valve lash was off a little bit. Int was .014 reset to .010 ex was .008 and reset to .018. Air gap on mag was good at .014 set with brass gauge. cleaned with emery cloth and reinstalled. coil tested at 14k ohms. Put it all back together and it does the same exact thing

[pfrederi 17,663]

Was this a sudden problem  had it been sitting for a long time did it run reasonably well before??

 

Incidentally Main jet is 2-1/2 turns to start Idle is 2-1/2 also