Nikki Carb - Buy or rebuild?

[sblg43]

I am fixing a friends Poulan Pro tractor/mower. It has a Briggs 31P777 engine.
I found all of the gas had somehow gotten into the crankcase. As a matter of fact, there was more gasoline in the crankcase than there was oil.
This unit has a Nikki carb. At the very least, I am going to rebuild the carb with a kit from ebay for $30. However, ebay also has a NEW Nikki carb for $63. Both with shipping included.
I have fixed/rebuilt many carbs but never a Nikki.

Question is this - do I rebuild or do I buy new? I am paying the tab here because I owe my friend some labor in exchange for a motorcycle. I am not concerned about the cost - I just need to hear from somebody more experienced with Nikki carbs. Is there a quality issue? Is it any more or less difficult to rebuild than a Walbro for example? Should it be replaced with a Walbro?

This mower is about 12 years old and I think the gas got into the crankcase by leaking through a valve that probably needed adjusting. So the plan is to rebuild/replace the carb, replace fuel lines and add a fuel valve, add fresh oil and filter, adjust valve lash. I also have to replace the connector that connects to the spark plug - it rusted off (even with the rubber boot intact). I will be checking the breather and breather tube as well.

Thanks

[Deere2me]

Repairing em ain't difficult, just pay attention to the bowl gasket/O ring, and the main jet/Oring. This should help :http://outdoorpowerinfo.com/repairs/briggs_intek_single_ohv_nikki_carb.asp
On most riders I work on, I install an inline fuel shut-off, cheap insurance. The gas got into the crankcase 'cause the carb inlet needle didn't seal/stop the flow, for whatever reason.
You also wanna make sure the solenoid pintle is not gunked up, I use carb spray and high pressure air to blow em out. You'd be amazed at all the crap that can be trapped in 'em.

[bobodu]

I tend to buy new these days. Rebuilding is often an iffy situation.

[creia]

[quote="sblg43"]
Question is this - do I rebuild or do I buy new? I am paying the tab here because I owe my friend some labor in exchange for a motorcycle.

What make/model/year motorcycle?
Michael

[KE4AVB]

I am fixing a friends Poulan Pro tractor/mower. It has a Briggs 31P777 engine.

I have fixed/rebuilt many carbs but never a Nikki.

No different from the cleaning and reassembly point just different gaskets and jets.
I normally Clean and Rebuild them here. A couple notes about the carburetor kit you may need an alternate bowl gasket set as I have ran into a couple where the carburetor had a different setup. Most times the kit will have correct gaskets. It just where the carburetor has been changed out in the past. The other is that the main jet is not include and must be ordered separately. They have tiny o-ring on them that allows them to become loose causing problems; sometimes they are so loose that they fall out when you take the fuel bowl off. This jet size will depend on your engine's type number. One other note you must carefully re-assemble or you will have fuel leaks from mis-aligned fuel bowl gaskets.

As for a carburetor on Ebay for $63 it is going to be the Fuel pump fed version P/N 794572. If your engine is gravity fed then you will need the 591731 (replaced 796109) and it going to be more expensive at +$85 with shipping. Putting a pump fed carburetor on gravity fed system is going to cause fuel delivery problems.

[bluemower]

before ordering a carburetor kit, open the carburetor to examine internally. If you see any corrosion or water deposits, a new carburetor is probably the best decision.

[sblg43]

This should help :http://outdoorpowerinfo.com/repairs/briggs_intek_single_ohv_nikki_carb.asp
On most riders I work on, I install an inline fuel shut-off, cheap insurance. The gas got into the crankcase 'cause the carb inlet needle didn't seal/stop the flow, for whatever reason.
You also wanna make sure the solenoid pintle is not gunked up, I use carb spray and high pressure air to blow em out. You'd be amazed at all the crap that can be trapped in 'em.

I find that outdoorpowerinfo.com is an amazing and wonderful place! I agree with the cheap insurance concept, I stock up on fuel shut-off valves for that same reason. Having a shut-off valve also makes future carb work easier. Thanks for the input.

What make/model/year motorcycle?
Michael

It is a 1982 Honda Silverwing GL500I Interstate that has been sitting in a ladies garage since 1992. It's in great shape but I have to replace everything that's rubber. So far, I'm into about $400.

before ordering a carburetor kit, open the carburetor to examine internally. If you see any corrosion or water deposits, a new carburetor is probably the best decision.

Wonderful advice - I was almost ready to order - I will wait a bit until the carb has been inspected more closely.

Thank you all for the great info. I'll keep ya posted.

[71gtx471]

Hi all newb here,I have found on nikki or walbro carbs that fuel seeps past the brass inlet seat & carb body if the carb is worthy of rebuilding the cure for this problem that works for me is to apply a small amount of red loktite to the already cleaned carb around the inlet seat & body,then take a small soldering iron & insert it into the seat & allow it to heat up & cure the loktite.this also helps the Loctite to seep down between the inlet seat & carb body. allow it to cool down then finish rebuilding.