OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Briggs & Stratton Engines Starter motor on my B&S

So, after getting the carby issues sorted I have found the next problem.. the starter motor.

The photo is a little blurry but I think I can work out what's going on here. The gear doesn't appear to be coming back down after the motor has started and hence all the teeth are gone. I guess that's what happens when you get old, lose all your teeth



My plan would be to buy this (https://www.outdoorking-forum.com.au/index.p...mp;cPath=193_195_204&products_id=369) and replace the drive assembly.

Two questions:
Will that solve the problem?
How do I replace it, is it just the pin holding it all on? be great no having to disconnect the fuel tank again

Thanks
Nathan

There are two ways that damage to the starter pinion could have happened: staying engaged after the engine starts (which is what you have suggested) or "milling": trying unsuccessfully to engage when the engine is stationary (i.e. not rotating). To find out which of them occurred you will need to inspect the teeth of the flywheel. If it has been staying engaged, all of the flywheel teeth will show wear marks and/or be partly coated with aluminium. If it has been milling, the only damage to the flywheel will be on the bottom edge of its teeth, mainly in one single area (just before compression). Your picture may be indicating aluminium smeared on the flywheel's teeth, but it's not a great picture - it's up to you to look.

The causes of staying engaged versus milling are quite different. Staying engaged falls into two generic types. Option 1: the starter has been kept energised for a longish period while the engine was running. Option 2: the starter's gear (pinion) has tended to stick on its vertical slide along the starter motor's shaft. Milling, like Option 2, is caused by the pinion not sliding well along the shaft.

If you have aluminium on your flywheel gear (ring gear) the next diagnostic question is whether the over-running clutch (sprag clutch) between the shaft and pinion shows wear. It will be worn if Option 2 is the problem. If Option 1 is the problem the sprag clutch probably won't be worn, but the starter motor itself may show signs of wear, overspeeding, or both.

You have to remove the entire starter motor to work on the pinion. It is secured by the two nuts just below the pinion.

Do not repair the starter until you know what caused the damage. If Option 1 is the problem, the damage may recur unless you find and cure the underlying problem. (The problem may have been some act of stupidity by the former owner, but whatever modification he/she made to the wiring may still need to be fixed).

thanks.. I will take a better photo tomorrow. the battery in the camera died just as I was about to take that photo this morning so I used the phone instead.

Will try and see which problem has been happening..

will see if I can get the starter off without taking the tank off completely.. had enough of draining and re-filling the tank

Nathan

Nathan, I'm not saying an experienced technician couldn't remove the pinion mechanism without taking the whole starter motor off, but in this case you need to inspect the starter motor on the bench to see whether it has been trashed by running continuously.
Way back in my student days I recall a guy whose scooter's ignition switch (and everything else on the scooter) was worn out. He found himself 50 kilometres from home late one night and in a fix: the engine would only run while he held the ignition switch pushed slightly inward. (This is a very common problem when foolish people have had a heavy bunch of keys and dangly stuff hanging from their ignition switch for years). Unfortunately pushing the ignition switch inward activated the starter motor on that scooter. You guessed it: he rode it 50 kilometres while holding the ignition switch pushed in, so the starter motor ran continuously.

Nathan,

Below is some information on the starter.

Thanks for that Bruce - it looks in the diagram as if the starter has a Bendix drive, not a sprag clutch drive as I had guessed. If so, the clues I suggested Nathan follow to see whether the problem is Option 1 or Option 2 won't work. It also means the starter motor's bearings will probably be in sad shape, from turning at very high speed for an extended period.

I have ordered the bits to replace the top part. I will let you know how I go.

I think the problem is that it hasn't been lowering and would have been spinning at high speed by the engine but will see how we go. I have limited time to work on it so I figure I'd get the bits and then check it out when I pull it off...

If it turns out the starter motor is worn out, you may waste some money on a new Bendix drive for a useless motor. Not the end of the world I guess.

that's what I figured. the starter motor seems to go OK but spinning freely is a little different to turning the motor. until recently it was cranking it over fine.

If there is no slack in the starter motor's bearings, it is probably either OK or needs no more than minor maintenance. If there is slack, it is unlikely to be satisfactory - there is normally very little clearance between rotor and stator, so if the bearings are slack the fixed and moving poles will touch each other (known as "poling"). This results in poor performance and further damage.

Sorry if this is in the wrong place just shows im no computer buff ok down to problems
homelite E150 Carby was give a weed eater with E150 moter and a caby C1umain body by choke H10B 85P
Clean in side dia look oh but looks like it had a bulb hanging underside as there is a plate holding wht looks like plastic with two vents one to the out side pipe one into carby
?question runs good if you put petrol mix into air cleaner
is it missing a buld or am i missing the point Erica

So I have the starter motor off and got the new bits ready to go on. I take it I just get a hammer and a small "something" and hit the roll pin to push it out so I can take the parts off?

Erica, this is in fact a fairly spectacularly wrong place for this - it needed to be a new thread under trimmers.
I am not familiar with your machine and I haven't followed your explanation well, but you said in Shout Box that you have a fuel starvation problem. One fairly common source of this problem is the air vent into the fuel tank not working. You can check whether this is your problem easily by leaving the fuel tank cap loose and trying the trimmer outdoors with no load, keeping the fuel tank cap pointing upward. Please be very careful, because if you tilt the trimmer fuel will spill out near a running, spark-ignition engine.
I'd appreciate it if Bruce or Deejay would move these posts to a more suitable place - I don't have a clue how to do it.

Got the starter sorted and the engine is going again now.. I ground the end of a nail and used that as a punch to remove the roll pin, what buggers they are!

I will now continue my carby thread to sort out the "lean" issue.

Nathan, you are supposed to use a pin punch to tap out the roll pin. It is just slightly smaller diameter than the hole, very hard, and has a flat end. A pointed end (such as a nail has) is bad because it tends to expand the roll pin and make it harder to get out. Even with the right tool they are a bit of a pain to remove and install.

I ground the pointy end of the nail to make it flat, was the perfect size, worked anyway

I've done the same thing when I didn't have the right size of pin punch. (Unfortunately one of the standard pin punches seems like just the right tool to unscrew the spool part from a Massey 40 Industrial's power steering control valve spindle. If it is really, really tight, the outcome is a broken pin punch, and then you take the valve to the tractor dealer to disassemble. Since then there has been a gap in my range of pin punches.)

My custom made roll pin remover worked a treat, once the pin decided to start moving.. best thing is that I can throw the tool out and make another one when I need it (hopefully never)