Cub Cadet 782 fuel problem?

[dwid]

I was recently given an older hydrostatic Cub Cadet 782 after purchasing a home that had a lawn big enough to warrant a rider. It had been sitting for the past 3-4 years, with the initial reason being that it would stall when the mower deck was engaged. It was one of those "if you can get it to work, it's yours" deals.

I cannot read the engine tag anymore to say what model it is, but the air filter assembly says Kohler Twin 17.

The engine would initially start if you primed the carb with a little gas, but would not idle very well, and would sputter and stop after 15-20 seconds.

Once I got it home, the first thing I did was to drain the old gas from the tank and lines and replace the in-line fuel filter. Next I took apart the carburetor, cleaned it out, and installed a carb kit (Cub Cadet KH-25-757-02, Kit, Kohler Carburetor Overhaul). I was unable to get the gasket that goes at the joint between the 2 halves of the carb, so I used a silicone gasket maker. I then replaced the spark plugs, one of which was white and chalky on the tip, one was blackened with a small amount of oily buildup.

The engine now will start decently with a bit of coaxing from the choke and throttle lever, and when started it will run fine, even in high and low idle. The trouble comes when I try to move it or engage the mower deck. The engine will start to lose power, and then sputter and die. I have messed a bit with the fuel and idle adjust screws to try and improve things, but without a manual I do not know where they are "supposed" to be and am playing it by ear.

My current thoughts are either fuel pump or something in the carburetor beyond the carb kit, but since they run $50 and $220 respectively, I thought I would seek a bit of advice before I go and "try" one of them.

I am certainly not a mechanic, but it seems like it is a fuel problem since it does not flat out die or anything that would lead me to think it is electrical, and I am not sure what else it could be. I am a bit concerned that one plug burned differently than the other, but at this point I do not see how that could cause it to die when engaging the deck or transmission, yet allow it to idle fairly smoothly.

Thoughts? Thanks in advance.

[Eugene]

I have never messed with one of the Kohler twin cylinder engines and have no manuals on them either.

My first thought is ignition timing.

If the engine continues to run and run well not under load. Fuel pump is working and carburation is probably pretty close. Suggest putting some carburator cleaner in the fuel tank.

They are repair kits for some of the Kohler fuel pumps - $13.00 range.

Recommend checking valve tappet clearance and a compression check. If everything checks out OK then suggest a full tune up.

Eugene

[wdeturck]

Here is a link to the KT-17 Manuals that could also be found on the Kohler site for free down load.

http://ihregistry.com/manuals/kohler.php

The carb is suppose to be set under load so there is a fuel supply problem if it dies when starting to move or engaging the mower blades un less something is binding like the drive shaft or spindles. the only ignition timing on them is the point setting. should be set with a timing light?

[junkman1946]

Does it idle and run no load smooth? Those Kt17s were famous for breaking connecting rods. The engine would still run on 1 cyl. until you put it under load. We referred to them as Kohler 8-1/2s. Check for compression on both cylinders. Frank

[junkman1946]

Does it idle and run no load smooth? Those Kt17s were famous for breaking connecting rods. The engine would still run on 1 cyl. until you put it under load. We referred to them as Kohler 8-1/2s. Check for compression on both cylinders. Frank

[dwid]

Does it idle and run no load smooth? Those Kt17s were famous for breaking connecting rods. The engine would still run on 1 cyl. until you put it under load. We referred to them as Kohler 8-1/2s. Check for compression on both cylinders. Frank

Thanks!

It ended up being the rod, but puzzlingly, was the rod that was on the opposite side, the one with the spark plug that was seemingly burning cleanly. I had expected it to be on the side that had the plug that had black residue.

The rod is on order, along with 2 sets of rings, (figured as long as I am in there, may as well take care of those too and hopefully avoid another episode later) and then I get to learn how to replace them.

Thanks all for the ideas. They were very helpful.

[Fordlords]

The broken rod usually takes with it a small section of the bottom of the iron cylinder casting. Sometimes it's salvageable, sometimes not. The rods suffer from lack of proper oiling on the KT17 series 1 you have- oil was just dripped to the crankpins from a low pressure "spray" oiling system. The odds are the crankpins are worn also, and the crank would have to be replaced or reground, which would also effect rod bearing size for both rods. You can give the rebuild a try, but once those engines blow they are often just boat anchors. Probably a good idea (and money saving one) to locate a good used KT17 Series II that has full pressure lubrication.

-Fordlords-

[Snotzalot]

Replace it with the Honda V-Twin.................................

[gitractorman]

I agree. The KT-17 is a boat anchor. Rebuilding it may work for a while, but typically you put much more time and money into it than you originally planned. Then you turn the key and it runs one time and blows up, or three times, or three months, but eventually it WILL let go.

The series II engines have pressure lubrication and are much better.

You could probably bolt in a Kohler 12, 14, or 16 single cylinder engine from an older Cadet (like the 1000 series), as they should work and bolt in easily. If you are planning to run a 50" mower though, you better stick with a 16hp or better.

If you are planning to keep and use the tractor, the Honda conversion/install is a great setup and will keep the tractor going forever.

http://cgi.ebay.com/18hp-Honda-Engine-E ... dZViewItem