460 questions

I'm looking for Kelly C who posted a message back in 07/17/04 ref 460 farmall question. The archives are my best friend but I could not find how things turned out for him (what he found was the cause)

If I can't find him I need the knowledge of the elders here.

I have a 460 farmall- rebuilt the motor/new pistons/sleeves/rings/ reman-carb/ shop rebuilt head/new valves/seats ect. new wire harnesses everything I could do to it myself.

Here lies the problem
runs smooth except for a super slight bobble every 20 seconds or so. Hours on hours spent on adjusting the carb but no luck clearing the slight bobble- perfectionist i guess. when I use her I could slowly run her up to full speed and she would run fine. If I ran the throttle up to quick the governor would kick in and she would die unless I backed the throttle all the way off quick enough. If I back it off quick enough It woudl sometimes catch at idle speed. Also sometimes if I'm driving it around at say mid rpm/ (plowing snow) and it hits deep snow (more load) she will die unless I back off the throttle quick enough. Most of the time though she just dies. To start her up again I have to choke it a tad but just increasing the the throttle wont get her started when I touch the starter to fire her back up.

I'm looking for some ideas. I have not looked for an intake leak yet and I have not checked the dist advance weights yet either. I was hoping to someone could direct me in the right direction. Could the governor be bad? or need fixin.

Make sure the heat riser valve is working, and maybe richen it up a bit. My 656 would die like that and I found that the heat riser was gone completely.

explain the heat riser? what would a guy look for to see if its bad or not?

Heat riser is on the manifold. Has a spring loaded weight with a butterfly inside that directs exhaust gas around the intake portion of the manifold directely above the carburetor. It must work free with a spring that is in good condition. Problem is over time they either stick, or burn up inside manifold and also the passages around the intake become filled with carbon and the only remedy is to take them apart and completely clean and replace worn out parts. Weight should be straight up and down in cold positon and pretty much stay there in cold weather unless worked heavy for period of time.It moves about 80 - 90 degrees full movement toward front of engine if working correctly. Getting the manifold apart is hardest part, cleaning those passages around intake is difficult also. I always took them apart on every valve job or overhaul on all those little six banger gasoline engines and that way they usually weren't as bad to get apart.

Hold your hand over the throat of the carburetor and see if you have good suction. Poor suction means low intake manifold vacuum. Could be a leaky manifold. I would check the valve clearance too. Hal

Sounds good. I did not take it apart during the rebuild but the weight does move freely. I dont think those halves have been seperated in some time cause the top of the bolts are rusted down a size or so. Can the flapper on the the heat riser rust or be burnt off of it? I guess I'll grind off the heads of the bolts and try to get the haloves apart. The other day I saw what appeared to be eccessive carbon build up on the tops of the pistons while I was adjusting the valves. The plugs were also very dark. sound Too rich or timing off???....

The first thing to look for is that coil spring and the peg it mounts to on the outside of the manifold. If the spring is missing or not functioning properly, you'll have a cold-blooded engine. It almost sounds like this one has an intake manifold gasket leak. Have someone spray a fine mist of starting fluid about a foot away from the manifold and see if it runs better.