LA 105 - fuel in airbox

Kish318420 · Apr 9, 2019

That's because of the nikki carb on the Onan has a few pages on calibrating (measurements) the float/inlet valve any time you replace the inlet valve (rubber tip develops a ridge overtime) or the valve seat (which screws into the base). It is set to get the right travel and pressure (closing the inlet to the bowl). But carbs do go through engineering changes that are mandated by the government or the bean counters over the years. So things do change, including the style of carb for vertical shaft versus horizontal shaft engines.

In regards to manuals:

Understand that Deere, with the engine deals, require the manufacture not to offer the exact manual on-line. This is so the owner will have to buy it from Deere if they want to have the exact manual for the engine service/repair. Same thing with the parts catalog (PC)

That is why I stated getting the TM and the CTM which will have that info.

jgayman · Apr 9, 2019

jchester404 said:
The second poster in this thread had suggested it. I found that I have a Nikki carburetor and I read that there isn't much calibration that needs to be done with the Nikki, what kind of calibration I would do on a carb I wouldn't know yet. I suppose inlet valve calibration isn't a thing?

One problem is that the float hinge (the part that holds the seat) is made of plastic. So unlike the old days where you simply bent a little metal lip to set the float height, you now have no way to easily adjust it. I have seen folks who heat up the part with a heat gun and then bend the plastic but you have to be very careful. If you happen to have a Chinesium carb rebuild kit the parts can be hit and miss and you can end up worse than when you started.

jchester404 · Apr 9, 2019

SOLVED.

I changed the float bowl gasket, valve needle, and main jet and it started right up and idled fine. No more leakage into the airbox. The gasket, and especially the o-ring, inside the float bowl had basically disintegrated. The main jet had corrosion and the o-ring to that was almost non-existent.

If anyone is having a similar issue the part numbers are:

B & S 698781 - Gasket/O-ring
B & S 696136 - Valve Needle
B & S 699733 - Main Jet

I ordered the gasket and needle off of Amazon and received genuine parts from Briggs and Stratton. However, I decided to order a Nikki "Carburetor Overhaul" that also included the listed gasket and needle as well since it was only $11.00 and I wanted to change the gasket between the carb and engine block anyway. I recommend ordering the float gasket and needle separate as I did because the float gasket from the "carburetor overhaul" was poor. I did use the main jet and it's working fine.

Hope this helps anyone in the future and I appreciated everyone's help.