Need help with my Troy bilt lawn tractor

navycop · Post by **navycop** » Fri Oct 08, 2010 6:27 pm

My friend is giving me his 17.5 hp lawn tractor. I started it up the other day, I should say I tried to start it up. It ran for about 30 sec then cut off. I bought a new battery (old one was dead) and new spark plug. Now it just makes a "noise" when I try to start it. It is like a GRRRR sound.

JPG · Post by **JPG** » Fri Oct 08, 2010 7:38 pm

navycop wrote:My friend is giving me his 17.5 hp lawn tractor. I started it up the other day, I should say I tried to start it up. It ran for about 30 sec then cut off. I bought a new battery (old one was dead) and new spark plug. Now it just makes a "noise" when I try to start it. It is like a GRRRR sound.

Need more detailed/explicit description of 'GRRRR'.

mickyd · Post by **mickyd** » Fri Oct 08, 2010 7:46 pm

Is the motor turning over?

fjimp · Post by **fjimp** » Fri Oct 08, 2010 8:24 pm

Is the choke operating properly? I recently had a fellow who owns one tell me after several days of Grrrrrr, (I didn't hear if the growl was from the tractor on my friend) he discovered the choke was open and stuck. Something about a broken spring. fjimp

Ed in Tampa · Post by **Ed in Tampa** » Sat Oct 09, 2010 12:33 am

navycop wrote:My friend is giving me his 17.5 hp lawn tractor. I started it up the other day, I should say I tried to start it up. It ran for about 30 sec then cut off. I bought a new battery (old one was dead) and new spark plug. Now it just makes a "noise" when I try to start it. It is like a GRRRR sound.

Check the fuel filter, check the diaphram on the carb that acts like a fuel pump. Both go bad and especially if the tractor sat for any length of time. Your tractor engine may be big enough not to use the diaphram but check to make sure.

Grrr sound may be you starter motor running but not kicking in the gear. Again depending on how long the machine sat, that gear on helical shaft may be cruded up and not engaging the fly wheel on the engine.

Lastly did you install the battery with the right poles? Most small tractor batteries come with the negative and positive on either side.
If you have wires switched the starter will run but because the helical shaft is turning the wrong direction it won't kick the starter gear up to engage the fly wheel.

That is the common problems if it doesn't start after checking these let us know any new symptoms.

cincinnati · Post by **cincinnati** » Sat Oct 09, 2010 1:32 am

If you go to Lawn Site . com there is a repair forum. A few on that forum are small engine mechanics. Very, very helpful bunch there. I read through it often just for educational purpose.

http://www.lawnsite.com/forumdisplay.php?f=35

navycop · Post by **navycop** » Sat Oct 09, 2010 1:33 am

Ed in Tampa wrote: Grrr sound may be you starter motor running but not kicking in the gear. Again depending on how long the machine sat, that gear on helical shaft may be cruded up and not engaging the fly wheel on the engine.

Lastly did you install the battery with the right poles?
That is the common problems if it doesn't start after checking these let us know any new symptoms.

The GRR sound. It sounds like if you ever tried starting your car after it was already running. The battey is right. The POS on RED and NEG on BLACK. The part under the hood spins sometimes when the key is turn. But it just not spin very fast. I wish there was a way to pull it like you would on a walk behind mower. Maybe that would boost it?? What is the helical shaft??

burkhome · Post by **burkhome** » Sat Oct 09, 2010 6:58 am

If the starter is not turning the engine over fast enough, and the battery is good, have the starter checked for drag. First check all connections for corrosion. There is a slight chance of hydrolock. If for some reason your engine has pumped oil or gas into the cylinder, you could experience similer circumstance. Your engine could be a single cylinder or a twin. Pull the spark plug or in case of a twin, both plugs. Turn the engine over. If it turns freely and shoots liquid out of the cylinder, hydrolok is the problem.

Ed in Tampa · Post by **Ed in Tampa** » Sat Oct 09, 2010 9:59 am

navycop wrote:The GRR sound. It sounds like if you ever tried starting your car after it was already running. The battey is right. The POS on RED and NEG on BLACK. The part under the hood spins sometimes when the key is turn. But it just not spin very fast. I wish there was a way to pull it like you would on a walk behind mower. Maybe that would boost it?? What is the helical shaft??

What I call a helical shaft is the end of the starter motor. It is designed so when it spins and centrifical force causes the starter gear to spin up the helicial shaft and contact the engine flywheel. Once the engine starts it turns faster than the starter motor and the gear is spun back down the shaft and out of way.

Some engines use the starter as both a starter and as a generator, but those are mostly old old designs.

If you tractor sounds like a car where you hit the starter and it is already running, that means the starter gear is going up the shaft but is not engaging the flywheel properly and the noise is from it grinding on the bottom of the flywheel.

Are you really really sure you have the battery in right. That noise will also occur if you have the battery terminals crossed and starter gear instead of riding up the shaft to engage the flywheel actually stays at the bottom because the starter motor is turning backward.

Without seeing it and hearing your description my money is on crossed battery connections, or some crud at the top of the starter housing preventing the starter gear from fully engaging the starter.

The starter motor is on the side of the engine usually two or three screws. Remove the engine shroud (the cover over the flywheel) usually a handfull of bolts and possibly a clamp or two to hold fuel line or cables out of way. With it off you should be able to observe the starter and flywheel interaction. If the gear never goes up the shaft the starter is wired backward (probably battery terminals, and yes I know I beating that horse bad) if it does go up but just rubs on the bottom of the flywheel then find out what is keeping from fully engaging.

Incidentally you can (I have) cut a hole in the screen over the flywheel large enough to insert a socket that will fit the nut on the flywheel. The chucking the socket in a cordless drill you can start your engine. Once the engine is started just pull the socket off the engine and stop the drill. Engine RPM at idle is less than 600 and small engines run at 3000 RPM at normal trottle so it isn't too exciting. Sears sells a plug in starter motor that could also be adapted. Works the same way but is machined to cam out socket once the engine fires. I have never had a problem with the nut hanging up.

Before anyone jumps on me I have done the above many times, admittedly the first time was scarey but once you do it you find the drill/socket and engine nut part company at probably 200 RPM or less and there is no drama. Most drills have a top RPM near the top RPM of the engine so even if it does stick just pull the trigger on the drill and turn the engine off. I have never had anything even close to this happen.