Estart setup

[Neil E.]

My estart only engages about 70% of the time. Works perfectly when it engages; spins up and buzzes when it doesn't. The buzz comes from the pinion teeth running against the top of the ring gear.

The starter motor was not square with the machined surface of the mounting hole so I made up a .032 shim to go betwwen the motor tabs and the PV cover tabs. This made no difference to the operation.

Next I measured up the vertical play in the bendix assembly. There was a total of .048", which is reduced to .032" by the two factory shims at .008" each. I was able to modify a .040" washer to match the shim ID/OD.

Including one stock shim that gave me .048" total. I put both above the assembly to reduce the engagement travel. The theory being that the unit travels a bit less to engage the ring gear. This made only a slight improvement. All testing was done with a fully charged battery.

The witness marks (from tooth contact) on the ring gear shows lots of engagement. My only conclusion is that I may need two gaskets on the ignition cover (and matching thicker spacer at the starter).

Has anyone else needed two gaskets?

There is a sprag clutch inside the bendix assembly and it works fine. It handles the momentary over-rev as the engine starts. I also tried some different greases/oils in the bendix unit and they made no difference.

 

[rgranger]

try doubling up on the side gasket. Mine was binding even after adjusting the starter, so I made a gasket of some rubberized material which was equal to about two gaskets.

The ktm starter I had to adjust with shims, the gasgas apparently gaskets.

 

[Neil E.]

Was yours binding it terms of "fail to release" (having trouble after starting the engine)? Mine releases fine, but has trouble on the initial engagement.

 

[rgranger]

Was yours binding it terms of "fail to release" (having trouble after starting the engine)? Mine releases fine, but has trouble on the initial engagement.

If I remember, that was almost 5 months ago, it just seemed to start slow and then stall, like it was dragging.

 

[Neil E.]

I had a more detailed look at my estart setup and have reached some new conclusions. My previous note about shimming is WRONG. Using a depth micrometer and gauge blocks I came up with an internal casting measurement of 2.253" face to face where the bendix would sit.

I clamped the spug gear in some soft jaws and rotated the pinion gear out firmly to full extension (bottomed against the clip ring). The bendix package measures 2.223" in length. This leaves a difference of .030" which can be shimmed. The two stock shims (.008" each) bring this down to .014", so only one more stock shim could be added.

The point I'm making is that the bendix has a cam action when it extends. This camming action should be taken up in the unit itself so no thrust tries to push the top cap away from the main casting. The camming thrust is absorbed at the clip ring. You will lose starting force when too many shims allow the cam action to try and spread the castings apart.

Pic of unit with tape holding it extended.

Since my problem is the initial engagement, I needed to determine if the pinion spacing was correct. I taped the unit in it's "thrown out" condition and reassembled the ignition cover. This kept the gears engaged and I could feel that there was a reasonable amount of play (pinion to ring gear). I could feel the play by rotating the spur gear back and forth.

There would be no value to adding an extra cover gasket as this would reduce tooth contact. Since my issue is intial engagement I decided that the tooth profile needed work. Automotive starter teeth are beveled on both sides to assist engagement; the GG pinion is only beveled on one side.

Pic of unit taped ready for grinding. Lower cover has been pulled down compressing the spring to create more room for the dremel wheel.

Pic of the finished gear. Factory bevel on the right side of the teeth. Added bevel on the left side.

I'll post up my conclusions after the next ride. My jetting parts have arrived so I'll start in on the carb soon.

 

[rgranger]

Cool, good luck and please post a follow up when you have time. This should not be that difficult, but my KTM had issues also.