stripping starter one way bearings?

C

cking

Member
Trying to start a YZ250 using a regular Coleman starter and a 500 plus cranking amp battery.
I bought 2 used starters and I have stripped the one way bearings on both. Are others having problems with starters with the one way ratcheting shaft? Does the starter have to have a one way bearing? What's the best affordable starter if I need a new one?
 
Where are you starting from crank or jackshaft? Or somewhere else?
One way bearing is an advantage.
It could be done with out , it could create other issues.
 
I am starting it right off the crank.
I didn't know if anyone else was having problems with the one way bearings or how the heavy duty starters were holding up. I assume all handheld starters have some sort of one way bearing to keep the starter from.getting ripped outta your hands or messing up the crank?
 
Actually most starters don't have a one way bearing. You're having an opposite thought process. If it had a one way, when the engine fired, the bearing would lock and consequently​ rip your arm off. Most starters are free spinning both directions and only the solenoid and motor provide rotation. From what I have used and seen, a standard high torque/gear reduction starter is more than enough with a good battery. Of course it's a bit more of a struggle for a smaller (300cca) battery but will still do the trick. Particularly with the decompression.
 
Actually, Briggs built flatheads for a long time with a robust one way clutch. I cannot recall one of those ever stripping. Adapt one of those to your starter if it is a concern.
 
Its not the starter that has the one way bearing, its the shaft that attaches to the starter.
So once the motor fires, the crank can freely spin. Here is a link to the ratcheting (one-way) shaft that comet kart sales... https://cometkartsales.com/Starter-Ratchet-Driver-11-Long.html
I had a 300 cca battery and it really struggled to spin this motor. Its a 250 2 stroke so there is no compression release.
If a one way bearing isn't needed, I am tempted to just weld the shaft together which will eliminate the stripped bearing problem.
 
You will need to put some relief in the drive /socket so it will release easier.
Maybe remove every other tooth from a 12 point .
A custom milled adapter would be optimum or starter nut.
We're there is a back angle that tends too push it off when the engine exceeds the starter speed.
Like you stated some form of brace that reaches the ground to avoid a broken arm or hand. Even just. An extension that braces on the chassis or engine.
I think it's doable without much trouble.
We used a 250 Honda to start a big twin it had a clutch though and sat on the gound.
Another guy used a chain saw with a modified bar to drive the start nut.
That could work has a built in Clutch . Course then ya got another engine to start.
66 Ford starter has a big enough bendix and long front shaft that could work.
 
Jimbo925 said:
Actually most starters don't have a one way bearing. You're having an opposite thought process. If it had a one way, when the engine fired, the bearing would lock and consequently​ rip your arm off.
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It sounds to me like you're not familiar with one way bearings.

When you hit the starter button, the starter shaft is driving the bearing, thus the lug, thus the engine. When the engine fires, the engine drives the lug, and the one-way bearing allows the lug to exceed the rpm of the starter shaft.
 
instead of welding the shaft , drilling it and driving a roll pin is an option.
actually as long as you have a good technique for starting and the starter is well lubricated. it should spin at engine speed.
top fuel and funny cars seem to use direct drive starters. any one know?
 
if I'm not mistaken, I think automobiles use one way bearings on their starters now instead of the old Bendix type. Maybe you just need a heavier duty clutch bearing?

Back in the 70s I used one way bearings in the rear wheels to act like a differential. Two bearings in each wheel. I never had any trouble with the bearings going out. I raced both Enduro and Sprint with that axle. It wasn't all that great an idea, but the bearings were good.
 
Anyone knows where to find the bearings and what size are they? Or replacement shafts with bearings? Seems like most kart storws don't have them anymore.
 
c king, A 300cca would never start my 270 2smoke, one way bearing yes, I went for a deep cycle marine battery 850 cca it will last a 2day show no problem and start anyone else that has the same starter nut . It sucks to have every else right only to have a crap battery keep you from leaving the grid.lol Chuck
 
cking said:
Trying to start a YZ250 using a regular Coleman starter and a 500 plus cranking amp battery.
I bought 2 used starters and I have stripped the one way bearings on both. Are others having problems with starters with the one way ratcheting shaft? Does the starter have to have a one way bearing? What's the best affordable starter if I need a new one?
Click to expand...
We had the same problem. The sprage clutch is just too flimsy in the smaller starters for the compression. We finally went to the Burris heavy duty starter. They are expensive, but no problems after that (that was 4 years ago and it's still working perfectly). Give Kurt Burris a call and tell him Uncle Bob recommended it.
 
nobozos said:
Rain I showed you the bearings how quick we forget Chuck.
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I saw the bearing on the starter but forgot you had some. Where did you get them? I thought yours were a different size too. I'll call you later today. i have your fuel pump.
 
The Coleman starter bendix came in three versions.

Standard ( one sprag bearing)
Heavy Duty ( two sprag bearings)
Jr Drag ( three sprag bearings)

They also came in multiple bore sizes to fit various size shafts starting at .470" all the way up to .625"

Coleman used various size motors over the years and put a sticker on the motor noting shaft size for quick reference.

The bendix was stamped ( ex. 490 RH HD) to note size, direction, and type.

The sprag bearing was a common 1/2" ID sprag that was press fit into the aluminum housing. The depth of the housing bore was determined by the number of sprags. The shaft would have the bearing (or bearings) slid on, and then pressed into the housing.

Typically, when you had a failure and tried to repair, the press fit was gone and the repair did not work.

You had to have the right bendix for your application. Most 100cc two strokes used the Standard. A flathead Briggs stocker required the HD and you really needed to make sure that you had it on the right stroke to make it start easy.

The triple bearing HD was for the really high compression engines, especially JR Drag engines.

We sold thousands of bendixes over the years. Most were replaced from misuse. It was never a good idea to leave your 100cc starter on the grid, as at some point, some Briggs racer who forgot to charge his battery would grab the first available starter on the grid and destroy your bendix, usually setting it back down hoping they hadn't been seen.

Brad Coleman never like selling the replacement bearings because of the interference fit loss. Plus he obviously made more money selling the complete bendix.

Pretty sure he has not made new production for 8 to 10 years.

The bearings can probably be found at McMaster-Carr or Amazon, and making a new tube should be a fairly simple task. I would highly suggest a triple stack of bearings if you tackle the project.

If your original bendix is a single bearing, you can probably bore the depth for the original bearings and keep the interference. If the original bearing did not spin in the housing, you may be able to heat it up and knock the shaft out and keep the original fit.

Regardless, when you put new bendix on motor shaft, file flats for the set screws if that is not already done, and put some antiseaze on before installation.
 
Michael Curry said:
The Coleman starter bendix came in three versions.

Standard ( one sprag bearing)
Heavy Duty ( two sprag bearings)
Jr Drag ( three sprag bearings)

They also came in multiple bore sizes to fit various size shafts starting at .470" all the way up to .625"

Coleman used various size motors over the years and put a sticker on the motor noting shaft size for quick reference.

The bendix was stamped ( ex. 490 RH HD) to note size, direction, and type.

The sprag bearing was a common 1/2" ID sprag that was press fit into the aluminum housing. The depth of the housing bore was determined by the number of sprags. The shaft would have the bearing (or bearings) slid on, and then pressed into the housing.

Typically, when you had a failure and tried to repair, the press fit was gone and the repair did not work.

You had to have the right bendix for your application. Most 100cc two strokes used the Standard. A flathead Briggs stocker required the HD and you really needed to make sure that you had it on the right stroke to make it start easy.

The triple bearing HD was for the really high compression engines, especially JR Drag engines.

We sold thousands of bendixes over the years. Most were replaced from misuse. It was never a good idea to leave your 100cc starter on the grid, as at some point, some Briggs racer who forgot to charge his battery would grab the first available starter on the grid and destroy your bendix, usually setting it back down hoping they hadn't been seen.

Brad Coleman never like selling the replacement bearings because of the interference fit loss. Plus he obviously made more money selling the complete bendix.

Pretty sure he has not made new production for 8 to 10 years.

The bearings can probably be found at McMaster-Carr or Amazon, and making a new tube should be a fairly simple task. I would highly suggest a triple stack of bearings if you tackle the project.

If your original bendix is a single bearing, you can probably bore the depth for the original bearings and keep the interference. If the original bearing did not spin in the housing, you may be able to heat it up and knock the shaft out and keep the original fit.

Regardless, when you put new bendix on motor shaft, file flats for the set screws if that is not already done, and put some antiseaze on before installation.
Click to expand...
Thanks.
 
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