OutdoorKing Repair Forum Forums Restoring, Customising and Modifying Tech Talk Screeching pull starter

Hi, Hope you can help with this one. I have an old B&S 3.75hp mower that screeches soon after starting. I have had this before on other mowers and I fix it by pulling off the pull starter, removing the piece that contains the ball bearings and add a drop or two of automatic fluid to the sock and bearings. However, this mower doesn't have that 5 sided bearing container. I got the mower from the recycle centre and maybe it was removed before I got it. I'm surprised the pull starter even works at all. Do you think somebody has removed the bearing container or does this older model not have that piece?

When oiling the ratchet type starters you shouldnt put oil on the bearings, just clean the crankshaft and the square center part (I gently linish the crank) and make sure the ball bearing cavity is dry.

Anyhow, On the motor you have pictured there, that is a newer model engine by the looks of it but has the wrong carby. There isnt a lot to go wrong with that starter and shouldnt be anything in constant contact to cause screeching.

Parker, you should not need to take off the part that has the ball bearings... from memory there is a small hole in the metal plug at the top and you can add a small amount of oil in thorugh there to lubricate the shaft and stop the screeching... No doubt someone will tell me if I am wrong?

While that hole was intended for oiling, these starters are very old now, the felt washer under the hole is dry solid and there is always a buildup of rusty dust, 10 or so years ago this method might have worked a lot better than it does now, always pays to spend 5 extra minutes being thorough to save pulling it apart twice.

Hi Joe Seem to think there was a little rubber sponge thing under that lid with the hole . I will sort an old engine out, (that's the only sort I have now) and pull apart just to refresh the brainbox.

As you say those engines are really old hat but were good engines if you looked after them.
My current use mower, used every week is a Rover with a Briggs and is now close to 40 yrs old. I traded it before I went on the farm; 25 yrs there and now 10 yrs back in Sale and still going really well.
Was used in Sale for at least a couple of years before going to the farm and would have been a couple of years old when I traded it.... Cheers Joe

Hi Joe, It's an old carby but still seems to work OK.

Thanks, Joe; The problem here is that there isn't anything to lube on this one. I know I'm mechanically challenged but what is causing the screech and how can it be fixed? I put a couple of drops on that hole but it didn't seem to go anywhere.

sparker, it sounds as if the piece of felt under the oil hole has rotted into a solid mass that won't absorb oil. It may soak in very slowly, over a period of days at least, or you might try a couple of drops of Penetrene instead of ordinary lubricating oil. Otherwise, you might need to replace the piece of felt. Remember though, you mustn't get liquid oil anywhere near the compartments that hold the balls: we are talking about a trace of oil on the shaft, not drops. The felt is supposed to smear a tiny amount, not let oil drip through.

Hi Grumpy, There is no place holding ball bearings. I think you're talking about the odd shaped piece that holds 5 ball bearings that you can take off. This mower doesn't have that bit, there's just a shaft. The photo doesn't show what is under the fins. I'll post another one but I can't do it until tomorrow.

Both of you guys, there is no bearings, bearing holder or spindle used on that engine, the cup you see in the photos is dragged by pawls in the blower housing, its a much newer design than those using the ratchet type mechanism.

Since there is no contact between starter reel and flywheel side of things while the engine is running it only leaves a few possibilities, I think either the mesh around the starter cup is hitting the blower housing or the start cup is making contact with the bottom of the starter from being mounted too high.

This engine has had a few tennants improvements already, going by the flywheel on it, it would have originally had a vertical pull side mounted starter.

The starter sounds similar to the ones Honda uses. A radial misalignment between the starter and the cup seems likely to produce a screech. Since the air cowl on the vertical pull starter engines didn't need to be well-aligned with the center of the crankshaft, I guess anything could happen. If the outside of the cup is touching something, there should be a shiny witness mark that is easy to see.

Why a previous tenant would have converted a vertical pull engine to radial pull is a mystery. I have always thought the vertical pull starter was one of the best things about the third design series (i.e. a 2 as the second digit in the model number) vertical crankshaft Briggs engines - along with the automatic choke. Well, those things plus lasting forever.

Thanks Joe, Grumpy,
As promised I've added another photo for posterity. You can see there's no bearing case like Joe said. I can't see any obvious shiny marks and I've been thinking it might be the mesh cup not being tight enough on the shaft, if that's possible. Mechanically challenged again.

Yes, as we've already gathered this is a pawl starter...

But sparker, I think you've got it, not so much the grill being not tight enough but more the edges of the grill being bent out a bit and dragging on the outside of the starter housing, look for shiny spots along the inside of the housing and report back!


Kori

i had an old rover once simillar screeching too i think , turned out it was the metal tabs that hold the rope pulley into the top cowling . adjusted and a little graphite powder and seemed to go away . sorry i dont know if its the same setup but worked for me for a year or more , and the rope retracted properly again too . hoping it helps ? cheers Dave

As Joe Carroll said, the obvious spots for the problem to develop are the mesh screen or the starter cup touching something stationary. I notice some odd shiny spots on the top of the cup:


One of Joe's suggestions was that the top of the cup might be touching the underside of the rope pulley. I may be missing something, but at the moment I don't see why the top of the cup is so shiny unless it is touching something while rotating.

We can't see the outside of the flywheel in the picture supplied. Note that there must be clearance - about the thickness of a business card - between the flywheel and the ignition module. If the flywheel has been touching the module there will be shiny or scratched areas on the outside of the flywheel. I haven't heard one screech, but it may be possible.

Thanks to all who have helped (or is it whom?)...anyway, to finish this one off there are shiny marks on the bottom of the wire cage and on top of the blower. So you guys were right about the problem. Put it back together and it is now fixed.


Edit: Grumpy, the marks you see on top of that cup look like shiny ones in the photo (well spotted) but were actually parts where the paint had flaked off.

Thanks for letting us know the outcome, sparker. I'll close this thread - if anyone needs to post to it, just PM a moderator.