Nikki carburetor clean and rebuild

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Crawfordville FL
42” Troy-bilt pony with 17.5 hp B&S Power Built. Has a Nikki carburetor. My brother-in-law’s mower, sat for a long time without being run.
When I pulled the fuel line off the carb something resembling mud came out. I pulled the carb off, dumped yellow gas out of the bowl. Sprayed everything out with carb cleaner, put it back on and she still wouldn’t run. It would run if I sprayed carb cleaner directly into the intake so I knew I had a fueling problem.

Took the bowl off again and it was dry, so I grabbed the big guns and shot some compressed air through the fuel inlet, popped the float valve off and sprayed the passages clean and ran air through all of them. Valve works because when I blow through it it will stop flow as I move the float.

I’m waiting for a new float valve gasket, old one has swelled and doesn’t fit. Gasket won’t be here until Tuesday, so what else should I check while I have it apart? I’ve replaced the air and fuel filters. The oil has been changed and I’ve got the battery on a tender while I’m waiting on the gasket. Oh and I have a new spark plug arriving tomorrow. Ngk iridium because they really do improve starting and my brother-in-law is not mechanically inclined and does no maintenance so best to have a “lifetime” plug installed.

I’ll be checking tire pressures, possibly shooting some grease into the steering gear. I don’t have the right kind of grease, the stuff I have is high moly wheel bearing grease. Valvoline I think.

Anyway, what else should I look over while I have the mower?
 
An ebay or Amazon carb can be found for $12-$30 some times, depending on model. Always look at the cost of a new carb before buying gaskets and attempting to clean it.
 
Those tiny little ports can get covered over by corrosion. Shop mechanics will use tag wire to clean them out. If there's any welch plugs, the ports underneath the welch plugs may be covered over with corrosion. You can use tag wire to clean the ports out. New welch plugs will have to be installed.
 
I have a Nikki carb on my Briggs 13.5HP, and more than likely it's the same model. Couple years ago it was $120 and the cheapest I've seen it now is around $75.
 
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