H still needs a tiny bit of choke or dies @ top RPM...

Absent Minded Farmer · Jul 11, 2012

It all started with figuring out what happened low idle on the new H. No amount of adjustment with the idle stop screw or idle jet made any difference. The governor control rod equalizer & springs were over-tightened & that bent the heck out of the equalizer bracket. I got it as straight as I could & no difference. Opened the carb to make sure I didn't forget anything... & I did!! Shame on me for not noticing the idle jet was missing. Darned thing was snapped clean off. I extracted the remnants & decided at that point to also change out the main jet & needle seat. Blew it out, put it all back together & now it dies like you push the outrun button in to kill the mag when you are at 3/4 throttle or better. Idles ok, though. Sooooo... this is what I've done so far: The carb has a new rebuild kit in it from CaseIH (354452R92), gave it the new jets & a fuel adjusting screw seat. Made sure everything was for the gasser carb. Float is set at 1 27/32" from the gasket surface on the top half (of carb) to the top of the float. My first question arrises here. Is that measurement taken with or without the gasket? I measured without.

Next thing to go was the old fuel strainer. The "nut" that's formed on top of the strainer was stripped round. It also had a roll pin jammed in the intake hole(?). The gas tank has been suction vacuumed twice & removed & swished once. Not a whole lot of dirt in there to begin with. The fuel line is clean, BUT it's a rubber line that dips down 3" or 4" into a "U" shape right before the carb. Could that cause the problem?

The manifold is new & has fresh gaskets. Last two things I can think to replace are the head gasket & head. Am I still forgetting to check something? Every last adjustment on the carb has been putzed with. No difference. It runs best with the main jet screw is at 5 1/2 turns & the idle screw is at almost a complete turn. Everything else seems to be ok.

Any ideas before I make this Earl Scheib job a lawn ornament or send it packing to a furnace in China?

Mike

Dean Olson · Jul 11, 2012

I measure mine without the gasket.

The low spot in the fuel line is not an issue.

I fought a poor running SH after putting on a new manifold till I figured out I didn't install the 1/8" pipe plug that goes into the manifold. Created a low vacuum situation.

Sounds like you have a fuel restriction somewhere or a vacuum leak.

rustred · Jul 11, 2012

but have you soaked the carb in carb cleaner? that is more important than new parts.it only takes a spec of rust or material in in a circut to cause big problem.

Absent Minded Farmer · Jul 11, 2012

No, didn't soak it. Sprayed down inside & out with cleaner, chased out all of the holes with a soft wire & compressed air. No constrictions or resistance that I felt anywhere. Not much crud, either. Must have gotten most of it the first time. It's possible there's a slight constriction somewhere. I guess I may have to let it soak.

Thanks,
Mike

Absent Minded Farmer · Jul 11, 2012

Just checked the pipe plug. It's not plugging a through hole. No drain holes either. Must have been a budget manifold.

Mike

El Toro · Jul 12, 2012

Open the main jet adjusting screw near the bottom of the carburetor. This will enrich the fuel mixture. Open it enough til it smokes then close it some. B&S have used this for years on most of their engines. My Wards tractor and Toro mower have this feature shown in this pic. Hal

mkirsch · Jul 12, 2012

(quoted from post at 17:54:18 07/11/12) Just checked the pipe plug. It's not plugging a through hole. No drain holes either. Must have been a budget manifold.

No, that means the inside of the manifold is BADLY corroded or otherwise coked up with something.

JT · Jul 15, 2012

When you replaced the manifold and gasket, did make sure all the gasket was off the head? I had the same issue, replaced the gasket, run a die down the studs to make sure threads were clean all the way down, still the same thing, removed manifold again, found some of the old gasket material was corroded to the head, took a small grinder with a scotch bright pad type surface, cleaned ALL the gasket off, down to really shiny steel, was surprised how much gasket was still stuck to head, anyway cleaned down to shiny steel, reassembled and it ran like a swiss watch...problem solved.....

rustyfarmall · Jul 15, 2012

(quoted from post at 16:28:10 07/11/12) It all started with figuring out what happened low idle on the new H. No amount of adjustment with the idle stop screw or idle jet made any difference. The governor control rod equalizer & springs were over-tightened & that bent the heck out of the equalizer bracket. I got it as straight as I could & no difference. Opened the carb to make sure I didn't forget anything... & I did!! Shame on me for not noticing the idle jet was missing. Darned thing was snapped clean off. I extracted the remnants & decided at that point to also change out the main jet & needle seat. Blew it out, put it all back together & now it dies like you push the outrun button in to kill the mag when you are at 3/4 throttle or better. Idles ok, though. Sooooo... this is what I've done so far: The carb has a new rebuild kit in it from CaseIH (354452R92), gave it the new jets & a fuel adjusting screw seat. Made sure everything was for the gasser carb. Float is set at 1 27/32" from the gasket surface on the top half (of carb) to the top of the float. My first question arrises here. Is that measurement taken with or without the gasket? I measured without.

Next thing to go was the old fuel strainer. The "nut" that's formed on top of the strainer was stripped round. It also had a roll pin jammed in the intake hole(?). The gas tank has been suction vacuumed twice & removed & swished once. Not a whole lot of dirt in there to begin with. The fuel line is clean, BUT it's a rubber line that dips down 3" or 4" into a "U" shape right before the carb. Could that cause the problem?

The manifold is new & has fresh gaskets. Last two things I can think to replace are the head gasket & head. Am I still forgetting to check something? Every last adjustment on the carb has been putzed with. No difference. It runs best with the main jet screw is at 5 1/2 turns & the idle screw is at almost a complete turn. Everything else seems to be ok.

Any ideas before I make this Earl Scheib job a lawn ornament or send it packing to a furnace in China?

Mike

Rule number 1. If turning those adjustment screws has NO effect on how the engine runs, the carburetor is still dirty inside.

Rule number 2. Refer to rule number 1 and get serious about cleaning that carburetor. There is still some crud hiding way down deep in the well.

H still needs a tiny bit of choke or dies @ top RPM...

Absent Minded Farmer

Well-known Member

Dean Olson

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rustred

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Absent Minded Farmer

Well-known Member

Absent Minded Farmer

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El Toro

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mkirsch

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JT

Well-known Member

rustyfarmall

Well-known Member

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