Replaced head gasket and now won't start without jumping off batter....

shinkle

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  • / Replaced head gasket and now won't start without jumping off batter....
Hello, new here with a head gasket question.
Briggs Stratton 19.5 HP on John Deere 115A, bout 12 yrs old maybe
Model 31P677
Type 0132B1

Bought an old mower from a friend, it started and ran ok but smokes alot. Started fine the day before repair. I replaced the head gasket, set rocker gaps, torqued all bolts to spec. Changed oil, plug, and all filters. All smooth except the intake pushrod just didn't feel right when reinstalling. Hard to explain but maybe like it wasn't seating just right but managed to get it where it felt ok. I manually turned the motor and the exhaust rocker would move pretty good but the intake rocker not so much. I went ahead and put it all back together but it won't start without jumping. The motor turns, lurches a litte, but acts just like a dead battery. Starts and runs good with a jump.

My question is, could I have done something to bind the engine, pushrods, rockers, that would keep it from spinning over to start without an extra boost from a jump?

Also, the mower sat outside the night before the repair at 22 deg....with the key in the ignition but off. Normally I don't leave the key in the ignition. Did this kill the battery ?

Thanks
 

bertsmobile1

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  • / Replaced head gasket and now won't start without jumping off batter....
The valves move the same amount
So if one is moving more than the other then the pushrod is not seated in the cam follower .
 

shinkle

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  • / Replaced head gasket and now won't start without jumping off batter....
The valves move the same amount
So if one is moving more than the other then the pushrod is not seated in the cam follower .
Thanks, is that an easy enough fix? What problems will this cause?
 

bertsmobile1

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  • / Replaced head gasket and now won't start without jumping off batter....
First get 2 nuts & double nut the rocker stud to make sure it is tight in the head
Note the grub screw is the locking devise on the rocker adjustment , not the adjuster.
Get a strong torch and look down the pushrod tube
With the engine at TDC on the firing stroke, both the pushrods should be the same height.
If not then one of them is bent or the cam is excessively worn

Rotate the engine, both pushrods should rise the same amount ,
If not the cam is excessively worn

Intake pushrod should open neat TDC on induction stroke, stay open while the piston is going down then close near BDC and stay closed till just before TDC when it opes a tiny amount to decompress the engine for starting
If not then the ACR on the cam shaft is busted & the cam needs to be replaced .

YOu can do all of this with the head on , rocker cover & rockers removed , finger lightly on the end of the pushrods .
 

shinkle

Member
Joined
Mar 13, 2022
Threads
2
Messages
12
  • / Replaced head gasket and now won't start without jumping off batter....
First get 2 nuts & double nut the rocker stud to make sure it is tight in the head
Note the grub screw is the locking devise on the rocker adjustment , not the adjuster.
Get a strong torch and look down the pushrod tube
With the engine at TDC on the firing stroke, both the pushrods should be the same height.
If not then one of them is bent or the cam is excessively worn

Rotate the engine, both pushrods should rise the same amount ,
If not the cam is excessively worn

Intake pushrod should open neat TDC on induction stroke, stay open while the piston is going down then close near BDC and stay closed till just before TDC when it opes a tiny amount to decompress the engine for starting
If not then the ACR on the cam shaft is busted & the cam needs to be replaced .

YOu can do all of this with the head on , rocker cover & rockers removed , finger lightly on the end of the pushrods .
Awesome, thanks.
 
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