Cold start throttle

[cywelchjr]

Not here. It doesn't get cold enough to freeze plain water here very often.

[Rasputin]

I went thru the carbs again. Everything checks out to the best of my knowledge. Did the colortune again, tweaking it patiently. I synched, colortuned, synched again...blah blah blah. The battery is charged up and in good shape. The plugs are a nice tan color and it seems to be running great.
It absolutely refuses to start cold without the throttle open a small amount. Man I am puzzled. I wish the roads here were in better shape so I could test ride the old girl. here is a pic of what it looked like around here the past month.

[dbeardslee]

Makes me cold just looking at that picture. Here's a link to some fuel and aire flow diagrams for mikuni carbs - maybe it will help with diagnosis. Looking at the slow system diagram it appears that with the butterflies closed they only draw air from the air jet on the side of the carb bell. Might be worth a shot of carb cleaner through the air jets to make sure they're clear. Then again maybe it's being hard to start because it's afraid you're going to take it out in that white stuff .

[dbeardslee]

Another thought

You mentioned the battery earlier - you might try a jumper cable from another source to see if the problem persists. A car battery would work. Probably best if the car isn't running.

[Rasputin]

Thanks for those diagrams. Very helpful to see that. I think it is too rich so I best be checkin the air routes again. As soon as it gets a bit of breathing room it fires right up, so that makes sense to me. I do have it on a load tested, fully charged battery, so I know that part is ok. Thanks ever so much for the help.

[XSokieSPECIAL]

here is a pic of what it looked like around here the past month.

Looks like a bad episode of Ice Road Truckers.

[Larrym]

Captioned for the Driving Impaired

Which caption:

"Chain of Fools" ?

or

"Fools Without Chains" ???

[Rasputin]

That is the main Hi-way between Edmonton and Calgary, near Red Deer on Dec/04/09. It was also about the time it was -46 in Edmonton. It is a four lane highway and the secondary gravel road is off to the right in the pic. Not every day we get that kind of stuff go on but often enough to make one nervous about travelling some of the busier holiday type days. We deal with that stuff all the time up here, but drivers get stupider every day and think they can still do 70-80 MPH. As a professional driver it just makes me cringe the way most of em drive. Then my kid heads of to Edmonton on the 23rd of dec to go shopping at west ed mall. Busiest time of the year on that hi-way and was sh*tty roads to boot. Then I have to think back an YUP I did the same sh*t when I was young.

[DenyP]

Touching on what Ivan asked - where are you setting your idle speed, engine warm, no choke? I like mine slower then spec. It will not idle cold with enricher set. I always have to add a little throttle at cold start.

Deny

[Rasputin]

Idle speed with engine warm is 1050-1100 Rpm after this latest reset of the carbs. That is the same speed it was set at in my previous posts as well. Am I setting it to low at that rpm?

[DenyP]

Your idle speed should be fine. Sorry I must have missed this in earlier posts, when I scanned them.

Deny

[cywelchjr]

Is this using the tach or another more accurate device? The manual and personal experience have shown the XS tach to be far too inaccurate at low RPM's to use to properly set the idle. You really need something other than the tach to set the idle speed. In my case, the tach tends to read a good bit high at idle, so it has to be idling too fast according to the tach to be idling at the proper RPM.

[DenyP]

I have both a Sun and a Snapon Tac myself

Deny

[Rasputin]

I have just been using the tach on the bike. I dont have any other type to set it with right now. Gives me something to think about for sure.

[skids]

Here's a link to some fuel and aire flow diagrams for mikuni carbs -

You know, those are some really good diagrams that are pretty close to the way xs11 carbies work. Good stuff.