John Deere d105 (Briggs and Stratton 17.5 HP) won't start...

leonh

Forum Newbie
Joined
Jun 29, 2020
Threads
1
Messages
3
  • / John Deere d105 (Briggs and Stratton 17.5 HP) won't start...
Hello yall,

This will be a long post because I want to let you know what I have done so far.

Re: 2012 Briggs and Stratton 17.5 HP 31G777 0171 G5

My John Deere rider was parked in the building a couple of weeks ago and I was
going to try to cut the grass after many days of rainy weather. I parked like normal
and tried to get started last Monday but the thing wouldn't start. The starter turned
the crankshaft but nothing happened. There several safety switches which prevent
starting so I checked everything that I could and finally replaced the ignition switch
and the seat switch. I cleaned the rust off the magneto and the flywheel to insure
good magnetic flux transfer. Finally, I found that he magneto was not firing the plug.
I ordered one from the dealer and got it last Friday. I put it on and the mower started
up! I was so pleased with myself until after it ran for about 15 or 20 minutes it began
to surge and just died. I decided that it must have been a fuel problem so I took the
carburetor of and cleaned everything that I could with carburetor cleaner. Pulled the
fuel cutoff solenoid and cleaned it to make sure it was free to function properly. I put
everything back together.

I tried to start the mower and it started smoking severely out the exhaust. As it turned
out, I found there was gasoline in the crankcase mixed with the oil. I thought I may
have made a mistake when I reassembled the carburetor so I removed it again and
went back inside to be sure the float would actually float. I made sure the needle was
positioned to turn off the fuel when the float pushed it up against the seat. Got it all
back together and reattached to the engine.

Well, I changed the oil and decided the only other thing I could do would be to adjust
the valves because it is not hitting a lick when trying to start. So, after adjusting the
valves to .004" on the intake and .006" on the exhaust, I tried again to start. The starter
turns the motor with little effort and it does not try to start. I repositioned the pick up coil
again to be sure it was the right place and checked for spark at the plug.

All seems to be good but it won't run!

There is a black plastic device mounted on the motor shroud with fuel lines entering
and exiting. Another line comes off and goes around to the other side of the motor.
I assume that was for assisting with vacuum to help the fuel pump. The fuel filter stays
full of fuel. Fuel comes out of the hose at the carburetor from that plastic device.

I think I must have missed something in my efforts to make this thing run.

Can anybody tell me what might be causing this little motor to not start?

Thanks and Peace,
Leon

It has a new fuel filter and air filter.
 

Scrubcadet10

Moderator
Staff member
Joined
Sep 24, 2017
Threads
248
Messages
6,431
  • / John Deere d105 (Briggs and Stratton 17.5 HP) won't start...
when you turn the key to ON, not start, but ON, you should hear the fuel solenoid 'click'... even though the solenoid may move freely it may be bad internally as it's electrical.
 

leonh

Forum Newbie
Joined
Jun 29, 2020
Threads
1
Messages
3
  • / John Deere d105 (Briggs and Stratton 17.5 HP) won't start...
when you turn the key to ON, not start, but ON, you should hear the fuel solenoid 'click'... even though the solenoid may move freely it may be bad internally as it's electrical.

Thank you for the quick reply. I have tried to listen for the click but I am afraid the railroads have ruined my hearing. However, I did test the solenoid before reassembling the carburetor and it pulls freely with the 12 volts applied amd releases freely when I remove the voltage.
 

leonh

Forum Newbie
Joined
Jun 29, 2020
Threads
1
Messages
3
  • / John Deere d105 (Briggs and Stratton 17.5 HP) won't start...
Well, I think I must have lied about the fuel. I am so sorry.

That black plastic device has nothing coming out of it and
I think the extra tube is for crankcase ventilation.

There was fuel coming through before I replaced the magneto
so I assumed the fuel passage was no different. Now I tried to
start it with starting fluid and it runs. I guess I need to bypass
that black plastic piece so I can get fuel to the carburetor. It
must have been an additional problem. leading me from my finger
around my elbow to my thumb.

Geeze!

I think I found the problem finally.

Thanks for making me double-check my work.

Thanks again and Peace,
Leon
 

Scrubcadet10

Moderator
Staff member
Joined
Sep 24, 2017
Threads
248
Messages
6,431
  • / John Deere d105 (Briggs and Stratton 17.5 HP) won't start...
full.png
Does it look like this?
Then that is the fuel pump, it's a diaphragm fuel pump that uses the reciprocating motion of the piston and air pulsing in the crank to pump a diagpraghm in the pump to pull fuel, acts like your heart.
there is input fuel and output and then a hose from the crankcase to the top nipple on it... Im not sure where the vacuum hose connects on this model, but i would make sure it is still connected good and not cracked or have any holes in it.
It's not often i replace one of these because they're bad.
 
Top