IH-454 Gas High Idle

This message is a reply to an archived post by Mrfix71 on May 22, 2013 at 12:48:16.
The original subject was "Re: IH454 Gas High Idle".

Another year and here"s the latest:
Determined the carb was not working correctly. Bought a rebuilt one off the internet and then ran compression test to find a burned exhaust valve. Replaced and lapped the valves, completely flushed and blew out every square inch of the fuel system, and with the new carb installed, the tractor ran pretty good. Except for an exhaust leak, she ran nice and smooth under load.

However, there was more than normal black smoke out the exhaust and after about an hour, there was a back-fire, out of gas wayyyyy to fast. At least 5 gal was used in less than an hour. Now she will barely run. Spent the last two days to figure out that the tractor is now going thru so much gas that fuel is dripping out of the carb inlet. Fuel is jetting out the unused inlet port with plenty of pressure and volume. On the down side, using a compression gauge, I am only getting about 5" of vacuum too. The new carb looks fine after cracking it open. Not much inside that could be blocked or restricted. With the rain and humidity...I gave up and thought I would inquire the "experts" out there!

Sounds like the carb is flooding, especially if it's draining fuel out when not running.

This can be caused by trash under the needle and seat, the float is set too high, the float had sunk, the seat is loose, the needle/seat is damaged. Open it up and recheck everything about the float, needle and seat, and the float hinge mechanism. Look at the gasket between the top and bowl, make sure it isn't holding the float down.

Rebuilt carbs are not always right. Assembled by us fallible humans, anything is possible!