briggs 18 hp twin on JD lawn tractor

[bjr]

A neighbor has a older B&S 18 hp twin with starting problems. this is a older valve in block engine and so I don't think it has a compression release system on it. He's changed battery, brand new, a new starter, new solenoid. I check to see if the drive system was disengaging. I remove the belt going to the mover deck. you can turn the engine over by hand by palm down and twisting on the flywheel shroud thing. My question is this could this starter be for a single cylinder engine and thus not having enough power to turn the engine at correct speed. I don't know if a single cylinder starter would bolt up or not. but this starter just can't crank the engine. I'm thinkin' wrong starter. but I'd like you guys opinion. bjr

 

[deepNdirt]

A neighbor has a older B&S 18 hp twin with starting problems. this is a older valve in block engine and so I don't think it has a compression release system on it. He's changed battery, brand new, a new starter, new solenoid. I check to see if the drive system was disengaging. I remove the belt going to the mover deck. you can turn the engine over by hand by palm down and twisting on the flywheel shroud thing. My question is this could this starter be for a single cylinder engine and thus not having enough power to turn the engine at correct speed. I don't know if a single cylinder starter would bolt up or not. but this starter just can't crank the engine. I'm thinkin' wrong starter. but I'd like you guys opinion. bjr

I'll let the more knowledgeable answer about the starter differences, as to whether one might have stronger amperage than the other, Although while this is still fresh on my mind I can answer that the single cylinder starters do no bolt on the same way as the twin cylinders do, You must remove the flywheel in order to remove or install the starter, it Bolts down into the top under the flywheel, on most single cylinder I've seen bolt in from the side, and not having to remove the flywheel, has it been check to be sure the engine isn't Hydro locked? a few years ago I had one to fill with gas into the block and would only turn over like having a dead battery, but if you held the starter engaged for any amount of time it would totally stop turning as would with having a dead battery, The starter would get hot and start smoking, .... what I found was the safety fuel shutoff switch had not shut the fuel off the last time in use, Resulting in filling the block with the fuel,
I realized this when I pulled the dipstick and noticed the oil/gas was all the way up well beyond the safe, and it smelled of pure Gas,

 

[handirifle]

I have the 20hp version of that engine. Unfortunately I am not home until omorrow nite, but I will see how mine bolts up. I think mine is easily accessible from the side. The starter on mine looks new so I will see if I can see a part number.

A rep from &S just told me these old engines had much larger displacement for their HP than the newer counterparts do. The best thing to do might be find the part number from B&S and cross check it with the starter on it. One question is, why did he replace the starter in the first place? Was the old one not working? Maybe it might have something to do with deepndirt's thoughts. Worth looking into.

Also, if that turns out OK, make sure the cable leading to the starter from the battery is heavy enough. Maybe a bad starter relay (if they have one???) might not be making a full connection. Just ramblin ideas.

 

[bjr]

He'd said He had fried the old starter, because he'd kept tryin' to use it and it just dragged (turned real slow, he had hook up the car battery with jumpers). I've see what he has done and all looks clean and tight with new cables. The fellow he had bought the mower from had the same problem and could never figure it out thus the sale of the mower. I don't know about internal injuries on the engine, but just walking up to it and turning by the palm of your hand it turns just fine. Is there possibly a overbuilt aftermarket replacement starter available? He needs to get this mower running for the spring gardening season. Any thoughts are appreciated. bjr

 

[RandyT]

Oregon makes a replacement starter they call a magnum that is supposed to be higher torque and speed than the factory starter I think the part number is 33-771

 

[deepNdirt]

He'd said He had fried the old starter, because he'd kept trying' to use it and it just dragged (turned real slow, he had hook up the car battery with jumpers). I've see what he has done and all looks clean and tight with new cables. The fellow he had bought the mower from had the same problem and could never figure it out thus the sale of the mower. I don't know about internal injuries on the engine, but just walking up to it and turning by the palm of your hand it turns just fine. Is there possibly a overbuilt aftermarket replacement starter available? He needs to get this mower running for the spring gardening season. Any thoughts are appreciated. bjr

Have you ruled out the crankcase being hydro-locked?
Is it real easy to turn by hand? an 18 hp twin should not be easily turn by hand, as one cylinders or the other will be under compression stroke, try removing the spark plugs and see if the starter will turn the engine over....... If so note how fast it turns, or if it appearers to have a catch in it while turning? while you have the plugs out reconnect the wires to the plug and test for good Blue spark, another thing I'm thinking about is if when the starter had been replaced does the Bendix gear mate up correctly to the flywheel? If you can get a visual on the starter Bendix note if the plastic gear teeth look excessively chewed up,
I have had to shim a starter on a single cylinder engine due to the misalignment of the teeth, although I dont think can be done on one if bolts on through the top,

Did this Mower happen to set out in the weather for any length of time?
The 16hp. twin Mower I recently purchased had been sitting out in weather for many years, and took a bit of effort to get going, The starter was froze/rusted I had to remove the flywheel and notice the flywheel and Coil had badly rusted as well, onces got rid of all the rust and lightly spray with wd-40 the engine will now wiz on over, and fires right up, incidentally I also put new ignition & solenoid switch and a CDI unit.... I hate later on having breakdowns only to start all over with troubleshooting again,

 

[bjr]

I see I didn't mention that he has had it running multiple times and it seems to preform well, no missing and good power. No, I haven't checked for Hydro locking yet. The mower is in his yard being guarded by a big ol' dog, so, I leave any troubleshooting up to him. bjr

 

[KubotainNH]

I have an 18hp and a 21hp that look exactly like each other. Mine are opposing cylinder type engines, I assume yours is too. The 18 is 20+ years old and like what you mention is hard to start. The 21 is on a 2000-ish Craftsman and it is also sometimes hard to turn over (really hard now seeing it locked up while blower snow ). What I have noticed is if you try to start it and it doesn't turn much then stop and try again. Seems if the motor stopped in a certain spot then there's just too much compression for the starter. It sometimes takes 2 or 3 hits to the starter to get it spinning. Also check wiring to make sure you have no voltage drop because of corrosion.

BTW, once the 18hp is started it runs like a top. Quiet and no smoking.

 

[bjr]

Has Anyone tried the Oregon Magnum Starter? Did it make the engine spin any faster? bjr

 

[deepNdirt]

so has your friend figured out his starting of the JD problem yet?