Ford LGT 100/ Kohler Engine Question

Hi- first time posting on the Garden Tractors page, but just wanted some opinions....

Picked up a 1976 Ford LGT 100 tractor at a sale last weekend. It has a 10-horse k-241 Kohler engine. 42 inch deck.

The tractors in fair to good condition, looks like it"s been maintained.

Runs ok, but when I hit the pto switch, and especially when I get into any kind of "heavy" grass, it just pulls the engine down to what sounds like half of it"s free-running rpm"s. Just kinda holds there as it lumbers through the grass. Turn the PTO off and the rpm"s come up to normal.

I"m not a small-engine guy, but have been around auto engines alot. What I"ve done so far is- new properly-gapped plug, new points, new air filter, and adjusted the carb screws like it says on Kohler"s website(basically highest rpm under load, etc). Seems to be decent fuel flow out of the tank when I disconnect the hose at the carb.

The engine doesnt stumble or act like a lean misfire or an ignition misfire, it just slows down.

I finished mowing with a newer "Murray" I"d got from my brother with a 16 horse engine and it never showed any signs of slowing down or losing power.

What am I missing here? Is a 10 horse Kohler just underpowered for this tractor(it"s factory) or is something else wrong? Is the old girl just tired? No smoke so rings seem ok...with the air cleaner off a bit of fuel seems to blow out the intake side of the carb at higher throttle settings...maybe it needs a valve job? What else can cause a small engine to lose power if it"s getting enough air and fuel? Muffler doesn"t seem to be plugged either btw...

thanks!
 
try setting the timing. They are timed by varying the point gap. You can find the manual on the web at Kohler's website.

Firing late can cause a lack of power and overheating.
 
I"ve downloaded the owners and service manuals from Kohler"s website and also tried varying the point gap. Too far either way at open throttle with a load(PTO engaged) slows down RPM and if I go to far either way it starts misfiring.

I moved the points to the smoothest-running highest rpm it would get to under the pto load and locked them down. Still no difference.

Is varying point gap the only way to adjust timing on these? It sure acts dead like a car engine does when it needs more timing.

A last note- went to mow after I"d posted and while it was really warm I was messing with the points, I noticed quite a bit of blowby coming out the breather cover(assuming that"s the cover under the carb that covers the valvesprings). It just might need rings after all.

Anyone know what cranking compression should show on a compression guage on one of these? I didn"t see that spec on the kohler website.
 
Check the fuel pump if it has one. My LGT165 bogged in high grass when the pump was dying.

You can't check compression on a K series Kohler at cranking speed due to the compression release. The Kohler engine manual says to turn the engine backwards against compression and it should bounce back. To check compression with a gauge, the engine needs to be belt to another engine to crank it above 1000 rpm to get past the compression release cut out point.
 
The timing should be set with a timing light. There is a timing window in the shroud. Pop it out and watch for the timing mark to be centered in the window, thennlock the points down.
 
If you suspect worn rings/leaking valve(s) do a leakdown test on eng,if rings leaking you'll hear/feel air coming out the breather valve or dipstick tube/oil fill hole,if valves leaking you'll hear/feel out intake/exh,if a leaking head gasket you'll hear/feel while checking around where head/block meet.A lot of the old K seriers tend to develop a head gasket leak in area of exh valve,if it has been a long term leak you'll see oil on head/block.

If you downloaded/saved K series manual look on pgs 8.2-8.3 will tell you the correct way to time eng either static or with a timing light.

Before getting to deeply involved with eng,check mower deck,you may have worn/bad bearings in blade hubs/idler pulleys & eng being overloaded due to mech drag when blades loaded in high grass,in addition blades may need sharpening/replacement.
 
Ron...I have the same vintage LGT-100 and if the grass is heavy (and wet)it does the same thing.There maybe nothing wrong with the engine and it's the nature of the beast. Sure guys with a lot more smarts than I have can and will comment. Good Luck
 
Compression test are not much use on these due to the compression release feature. A leakdown test is a much more useful method.
 
Yes the governor seems to be working. I did check and when the engine slows down while mowing, the governor does not move, it is still holding the carb at wide open throttle.

I will do a leakdown test and check the mower deck and reset the timing as the people above suggested. Thanks everyone!
 
The tractor is a Jacobsen painted blue with Ford decals. It's a good outfit.

A Kohler K241 at ten horsepower should have plenty of torque for a 42 inch deck. That engine should have a Carter/Kohler carburetor that has a #26 molded in the air filter side of the venture. When you throttle up from idle there should be a puff of black smoke. That tells you your setting is rich enough.

You could try a digital tachometer and make sure that engine is turning at 3600 rpm. That is where you have the full ten hp.

Make sure you can see daylight through the air filter. Those filters can look clean on the outside but still be plugged with dust.

Having the engine slow down when you engage the deck is a bad sign. Make sure all your pulleys are free, the deck spindles are free, and the belt or belts are lined up properly. Some decks are set up so the belt looks like it's lined up right but it drags on something when you are mowing. Don't ask how I know that.

Is the deck leveled properly? Are the blades sharp? Are the blades turning the right direction? Blade tips should go in the direction of the deck outlet/grass chute so they throw grass out the chute. Learned it all the hard way.
 
I have a Cub cadet 108 with the same K series engine. The linkage on the engine was so shot you could not believe!!!! The throttle shaft into the carb was shot too. $125.oo for the bushing job on the carb. It was an original Carter. The arm out of the side of the engine had an oval hole. The spring ends were almost ground off. All has been replaced, and adjusted as per the books. The parts were in the $60.oo range. Tractor runs so smooth and even now!!
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top