Nikki carbs

[CLStout]

New member here! Having some issues with the B&S Intek 20hp in my Ariens mower. The model number for the engine is 406777, type 0442B1. I had a surging problem, so I purchased a new carb. It appeared to be identical, except for the fuel solenoid. The OEM one was on the bottom of the fuel bowl that operated in a vertical motion. The new carb had a solenoid that was horizontal. I just assumed it was a modification for something that was an issue with the vertical one. Installation was easy, and upon attempting to start it, I had to use ether to get it to fire. Once it was running, it had the same symptoms as the OEM carb. I decided to remove the fuel bowls from both carbs and compare. In the OEM carb, there was a plastic part that fits over the plunger. The new carb didn't have any such part. There was a metal shaft built into the fuel bowl, with a rubber o-ring that was crushed during assembly.
I can't seem to wrap my head around how the horizontal fuel solenoid works to shut off the fuel. Can someone here offer an explanation, or maybe a diagram of that particular carb so I can better understand how it works? Seems to me that it's missing something.

Thanks!

 

[bertsmobile1]

All the fuel solenoid is required to do is cut off the fuel supply to the main jet so the engine starves as well as not having any spark.
IT is a EPA regulation to prevent the engine pumping out unburned fuel to the atmosphere.
So it is an on or off device.
Originally they simply replaced the bowl bolt but in that position they also accumulate all the debris that ends up in the float bowl and get gummed up so stop working .

 

[StarTech]

Something not right with the fuel solenoid as the 798779 solenoid here does have a white plastic tip used in the 798778 fuel bowls. Now if that that fuel transfer tube O-ring is damaged it can cause problems.

Now the after market KIPA solenoid is all metal but it still has a larger sealing end. Even the current Briggs solenoid has the all metal tip.

 

[CLStout]

Thanks for the replies. The solenoid you're showing is the one that came with the new carb. My question is, how does it function? I can see how the OEM one works, but I can't see how the horizontal solenoid works. There are no other moving parts in the fuel bowl, like there is in the OEM one. Am I making any sense here? It just seems like a part or parts may be missing.
Maybe if I could find a diagram of the new carb it would help?

 

[CLStout]

Well, this is depressing. I had disassembled the OEM carb, cleaned it, and reassembled it and installed it back on the engine. It started right up and ran very well. Idled nicely and accelerated well. So, today I am mowing, and it suddenly started surging. I turned off the mower deck, and headed for the garage. Then it smoothed out and began running well again. I started up the deck, and finished the lawn.

Any ideas what may be causing this?

Thanks!

 

[CLStout]

OK, researching the carb parts and I seem to be missing the main jet housing in the new carb. I guess I will be contacting the seller. However, I still don't understand how the horizontal fuel solenoid functions. Still trying to wrap my head around this.

 

[bertsmobile1]

Look and see where in the float bowl the main jet fuel hole is.

 

[StarTech]

If you missing the fuel transfer tube assembly you know it as the float is attaching to it. The main jet is inside this transfer tube assembly.

As for the fuel bowl the horizontal solenoid opens up a hole that goes to center of bowl and then that mates with the fuel transfer tube hence the o-ring for sealing purposes. Note the black wire in the below image that is fed through this hole.

 

[CLStout]

OK, I guess I may be incorrect. But the original carb had a separate main jet housing. I should take the float bowl off again and compare.

 

[StarTech]

Ah I went and looked at the IPL and you right as I was think of the single barrel version instead of the twin barrel.

Forgive me as I should had looked at the IPL again before typing. It should have awn me we are posting about a twin barrel with central transfer tube like the Kawasaki carburetor I working on but having to putting it back a few days as I wait on the transfer tube gasket that is coming in Monday.

and not this one.