Starter can not turn motor through compression stroke

[Jssussex]

Is it possible to have a weak starter motor. I have a Sabre 2000 mdl 1542HS that I have a problem starting and it has gradually gotten worse. It use to start if I backed the engine up to the end of the compression stroke, then when it started it had enough momentum to get through the compression and start the engine. The starter motor can spin the engine but stalls when it get to the compression stroke so it will not start. If I pull the spark plug the motor will continue turning. I've even bypassed the circuit and used my truck engine and jump started it at the starter motor ( bypassing everything) with a full automotive battery and still cannot force the engine to turn through compression. I can turn the head manually with difficulty but can slowly push it through the compression stroke.

Before I buy a new starter motor I want to confirm that a starter can get weak and not just fail.

I don't want to waste my money on a starter motor if I have some other engine problem causing too much resistance during the compression stroke.

 

[buickanddeere]

Weak battery, high resistance connections and over advanced timing while cranking. Could be the starter too. What is voltage on the starter terminal while cranking?

 

[PHPaul]

I would also check for bad bearings and/or brushes in the starter motor.

 

[Soundguy]

ditto. a worn bushing can put side force ont he start gear and make it bind!

weak brush springs or short brushes can cause issues too.

 

[Rocky Hoffler]

You need to do a draw test on starter to see how many amps it pulling. But it does sound if starter is the problem

 

[Clint S]

For any and all of the above reasons it can get weak. I just replaced the starter on mine and it was similar problem to yours. Sometimes it would turn over real slow, but start sometimes one crank and unable to turn over more. Replaced starter and cranks as it should, just be sure it is not your battery or wires.

 

[Soundguy]

Can do a v drop test on the wire to the starter, measure across wire while starting, use a low v setting like 1-10, etc

 

[Gary C.]

Sounds like it could need the valve clearance checked also. If it is too wide it will act as you described. Valve Adjustment, Compression Release and a Hard to Start Briggs and Stratton Engine

 

[k0ua]

Sounds like it could need the valve clearance checked also. If it is too wide it will act as you described. Valve Adjustment, Compression Release and a Hard to Start Briggs and Stratton Engine

Above is your answer... Famous Briggs valve adjustment problem.. happens to all of them sooner or later.

https://www.youtube.com/watch?v=0cWoEk5Guos

https://www.youtube.com/watch?v=PbYbSKN4CxI

your starter is fine.. I have a nice new one if you would like to buy it.. I bought it for the same reason as your problem.. it is not likely the starter.

 

[k0ua]

Further information. The starter solenoid may be damaged as well, as the high starter currents that are pulled when the tractor will not start on trying to roll the engine thru Top Dead Center pulls more current than is normal. The contacts can become pitted and burned. It is easy to replace. If it starts fine after the valve adjustment, then fine, but it has received a lot of wear and tear. Millions of dollars have been needlessly spent on starters for these Briggs OHV engines. I was a sucker that bought one too. and a couple of batteries. I still have that starter if you need it!