Need choke or it won't turn over

[johnny42]

Hey,

This year, unless I have a bit of choke, the engine will barely turn over. Brand new battery this year and I removed/cleaned/lubed the starter motor over the winter. At the end of last year, without me touching anything, the idle somehow got to 1200 rpm. I've since lowered the idle to 950 rpm

Wondering a couple things......

Does me lowering the idle have anything to do with starting the bike?
Could it be my sprague clutch?
I thought using choke simply enriched the mixture. Is there something else the choke does like interact with the starting mechanism?

I can certainly live with using a bit of choke while starting, but it's only been doing this this year.

The symptom is, the engine won't even turn over once. It just bogs and then nothing. With a bit of choke, the starter is robust. Even if the engine is warm, I need that bit of choke.

What's going on?

[DenverWinger]

If the battery is good the starter should turn that engine over with authority and a quickness.

Probably time to pull the starter and give it a good servicing. You'd be amazed what a new set of brushes will do for a weak starter.

[johnny42]

I pulled the starter this winter and cleaned and lubed. The brushes were fine. No where near the "replace" measurement.

The starter is robust and turns the engine over with vim. But only when I have some choke. Without choke it chugs once or maybe not even once.

I can live with this new procedure of using choke while starting. My question was to find out what might be causing this condition and if there's a fix.

[winguyjo]

all i can think is that movement of the choke cable is nudging a wire somewhere causing a temporary short or open in the starter circuit. the richness of the fuel mixture shouldn't affect the cranking speed of the engine in any way.
i would try wiggling the choke cable (but not actually pulling on the knob to actuate the choke) while hitting the start button and see if you can replicate this symptom.

[ct1500]

I would re-visit the starter work. The positive brush wires inside the starter when new had insulation and after all these years it is more than likely gone. If the wires are not put back into the starter housing just so, there can be small touching/shorting to ground problems. Get the new brushes and install and then come back with some good news.