New engine seems in a bind

Homer1

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Well, I've just finished installing a new V-twin CT series engine, 27 horse on a mower, but the starter seems to bind up trying to turn the crank over for the first time. Is this normal? Everything appears to be wired correctly, and the switch is functioning as it should, the starter just doesn't seem to have the balls to turn the crank. Should I manually turn the crank a few times and or remove the plugs and lubricate the pistons prior to initial starting? The starter is engaging, it's just attempting to move, and then humming loudly, but the crank only moves slightly and then stops.

Yesterday I noticed that the battery was low from where it has been sitting, and the PTO would barely engage, so I charged the battery this morning and assumed that might be all it was. However upon trying again this evening it's still doing the same thing.

Any advice is appreciated. I am no expert, but I am learning.
 

Scrubcadet10

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What is the cranking amps on the battery? Thats what matters.
 

ILENGINE

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Pull the plugs out and make sure there isn't oil or something else in the cylinders causing a hydrolock situation. then I would be checking the drive belts and pulleys for binding.
 

Homer1

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I'm not sure on the CCA for the battery, but I tried it again tonight and it did the same thing. I turned the crank by hand and it seems to be free, I am suspecting at this point the battery may just be bad. I am going to check the voltage again in the morning and maybe try to start the mower while it's charging to see if the starter will actually turn it over. If it does, the battery is just shot.

At least I hope that's all it is. I am anxious to get this thing running and out of my damn garage!
 
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If you do put a new battery on there and you still have drainage your wiring might be wrong somewhere.. I have seen a PTO clutch that was engaged and it drained the battery as a dome light in a truck would do in a couple days ........

Just a thought for you in the future ~!~!
 

Homer1

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Ok, old battery tested in at 12.4 volts this morning, but after trying to crank and just hearing buzzing with very little movement it checked out at 12.2, so I swapped batteries for a new one. New battery 350 cca, same as old tested at 12.5 volts. After hooking it up i tried to start, it was very sluggish to get going, but once the crank made a full revolution it picked up and cranked like it should. (I own the same engine on another mower with a smaller battery by the way.)

I cranked for 10 seconds, to allow fuel to pump to the carb. I let off for 10 seconds. I then cranked again and same result, sluggish until it made 1 turn, then it moved find for 10 seconds, but never fired. Let it sit 30 seconds, tried again, nothing, not even an attempt for the starter to fire.

Re-checked voltage at battery, 12.5 still. Cranked by hand a few times from below, smelling fuel in the exhaust slightly, so it's getting in to the intake.

Waited a min or two, tried to start again, nothing, no starter engagement.

I am scratching my head at this point.

Fuel solenoid is working, I can hear it. Fuses all good. I guess my major worry is why the engine is so damn hard to turn over, and why the starter only works when it wants to.

Going to post some pics later or tomorrow of wiring, to make sure I haven't messed up something obvious. Not sure how it could be wiring though. Solenoid is functioning properly. Engine easy to turn by hand until compression stroke, pulleys and belts move freely on drive pulleys.
 

Homer1

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Well, after fiddling more tonight before work I just broke down and decided I would jumper the solenoid connections to make damn sure it was functioning properly. I am using a brand new Briggs 4 wire solenoid, and as far as I can tell it's wired correctly. Voltage is there when turning the switch, other pin is grounded properly, battery to one pole and starter wire on the other. I removed the solenoid and sanded the paint below where the metal feet make contact with the frame to make sure it's properly grounded there as well. Still not getting the starter to engage.

After jumping the 2 battery posts it immediately tried to turnover with full power, so obviously something is wrong with the solenoid, or somewhere it's not making contact. I am going to investigate further tomorrow morning, but it appears the problem lies within the solenoid.

I've never seen a solenoid just half-way work and then other times not. Maybe I will try the 3 wire solenoid just to make things simpler.
 

ILENGINE

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I ordered a bunch of Briggs universal starter solenoids a few years ago, and every one of them failed within 1-3 starts. Briggs had to warranty all of them as failed. I decided to never use those solenoid again, and went back to the Oregon universal solenoids.
 

Homer1

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Well, good news. Mower is running. I went to a local TSC and all they had were the Briggs solenoids. I waited until our local repair shop opened and bought a 4 post Oregon and it's working perfectly.

I also changed the ground for the solenoid to an engine mount vs a bolt on the frame where I originally had it.

Funny enough that Briggs solenoid rated 1 star out of 5 most places I looked.

Thanks for the suggestions along the way. Hopefully if someone is having a weak starter issue they might track it back to the solenoid before loosing all hope.
 

Scrubcadet10

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WOO HOO! PRAISE THE Lord! :thumbsup:
 
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