Will this cause damage?: Sprockets forum: Grassroots Motorsports Magazine

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Aug. 22, 2011 10:08 a.m. Morbid Reader

The short story is that my XS400 is moody when first take off on it. Pull out of the driveway and onto the street and I have no throttle response, the engine cuts out for half a second then comes back and all but pulls the bike out from underneath me. It only happens on the first acceleration, and only after it's been sitting for several hours.

Through a rather spacey moment on my part, I found a preventative for this little hiccup, but need to know if I'm causing any damage by using it regularly. The other day I started the bike, which has 2 choke positions, one for starting and one for warming up, pushed the choke in one click and put my gear on. When I left, I forgot to push the choke the rest of the way in and it didn't hiccup. Rode about a block with the choke out, noticed that it was idling high, pushed the choke in and it was fine. Still no hiccup.

So, is it safe to make a habit of leaving the choke out until I shift into second, or am I going to cause damage?

Thanks :)
Aug. 22, 2011 10:52 a.m. 44Dwarf Dork

Yes your bike not warm enough to leave yet kind of normal leave the choke out one click at the end of the side street or next stop click it off the rest of the way. some bikes even had cables to the bars just for this.

44
Aug. 22, 2011 11:00 a.m. Mook New Reader

WAY back when I was the proud owner of my blood red XS400. One of the things I was schooled on by my dealer is that you sould start on full chocke, then moved to half choke until the engine warms up. You can tell the engine warms enough by hearing the idle "run up". I put just over 41k miles on that little bike, the first three years I had it it was my DD rain or shine, hot or cold.

Never missed a beat. I'd buy another on in a skinny minute if I could find one.
Aug. 22, 2011 2:26 p.m. Morbid Reader

OK, so leaving choke out isn't going to hurt anything. Thanks
Aug. 22, 2011 2:41 p.m. Woody SuperDork

That's the way chokes work.
Aug. 22, 2011 2:42 p.m. Morbid Reader

Sorry, my only other carburated vehicle was a dirtbike, still figuring things out
Aug. 22, 2011 3:33 p.m. 44Dwarf Dork

Nope will not hurt a thing except gas mileage if you forget..
Aug. 22, 2011 3:57 p.m. pinchvalve SuperDork

Choking most things for a long time will eventually kill them, but not a carb.
Aug. 22, 2011 6:28 p.m. Osterkraut SuperDork

Morbid wrote:

OK, so leaving choke out isn't going to hurt anything. Thanks

Well, for short jaunts. Leaving the choke out much past warm-up can cause some nastiness.
Aug. 22, 2011 8:33 p.m. Morbid Reader

Osterkraut wrote:

Morbid wrote:

OK, so leaving choke out isn't going to hurt anything. Thanks

Well, for short jaunts. Leaving the choke out much past warm-up can cause some nastiness.

I'm pushing it back in when I reach the stop sign on my street, about a block away.
Aug. 23, 2011 9:08 a.m. MadScientistMatt Dork

Morbid wrote:

Osterkraut wrote:

Morbid wrote:

OK, so leaving choke out isn't going to hurt anything. Thanks

Well, for short jaunts. Leaving the choke out much past warm-up can cause some nastiness.

I'm pushing it back in when I reach the stop sign on my street, about a block away.

That's about what I have to do on my street bike - on cold days, I need to leave the choke on for several blocks.
Aug. 23, 2011 10:01 a.m. Woody SuperDork

Eventually, leaving the choke out would create a lean condition and subsequent overheating of expensive bits, but you would have drivability issues long before that. It's sort of self correcting; you'd notice that something was wrong and then open the choke all the way.

It sounds as if you are riding the bike as it was designed to be ridden.
Aug. 23, 2011 11:45 a.m. RealMiniDriver Dork

Huh? How does leaving it choked create a lean condition? The purpose of choking (Brits call it enRICHening) is to feed more fuel. Sure, too much fuel will cause running issues, but not lean.

Or am I confused?
Aug. 23, 2011 12:47 p.m. 44Dwarf Dork

Woody's been eating to many of Bullseye's biscits... Choke lets in more fuel. On bike carbs it is an secondary air path to draw more vapor up in the the throat. 1 click out is a very small opening and is only effective at slow speeds once the throttle is over 1/4 open no flow though the hole is seen. If she were leaving with choke fully open then yes she'd have flow at higher throttle openings and would have the potential for carbon fowling the plug and or gas washing the Cly.