Cold Natured XS1100

[jyork]

Why is my '79 XS1100 cold natured at start-up, I've measured the floats/adjusted air/fuel mixture screws/sync'd the carbs/ good gas, following the manual, even consulted one of those Magic 8 Balls! still runs crappy at start-up!

Thanks
Jeff York
'79 XS1100 x 2 (black one-runs crappy, red one-repainting)
'80 XT500
Tulsa,Ok

[Dennyz]

I have a SF with 17K on it that is very cold blooded. It takes several mile of riding before I can take the choke off. I have complete gone through the carbs and even increased the main jets to 140s. It helped but still takes to long to warm up. My other XSs, come off the choke in 100ryds.

I suspect the valves are too tight. The P.O. had a valve adjustment done by a shop (first clue). The motor is very quiet when it runs, even cold I hear no tappet clatter (second clue). Too tight of valve shimming is like advancing the cams (sort of) which moves torque up the RPM range (If I remember correctly). This would be more noticeable at during cold starts (third clue).

This is my theory and I am sticking with it (at least until I check the valve shims).

[DiverRay]

Did you check the compression? If it has a low reading cold, and gets better when warm, that could be part of the problem. I know some of the bikes didn't run well cold because of problems in the "choke" circut. If you have one or two carbs with restricted ports in the circut, that could also cause the problems.
Number two reason, check your wires from the pickup's. My 78 wouldn't run well cold, until I repaired one wire. at low idle, it ran on two instead of four.

Ray

[beechfront]

#1 special has ALWAYS been this way. no work i have done to it has changed this behaviour.

it doesn't bother me. it starts up like a champ every time. runs great. i don't care if i have to leave the choke on for 5-10 minutes.

[John]

Cold blooded?

Mine starts right up within two revolutions of the starter, and without using the choke. I ride every day that it's not raining. The early morning (5 am) temps are in the low 40', high thirties, and it busts right off as soon as I hit the starter button. I keep the bike in an unheated garage everynight. I don't know if it's because of the increased compression of the big bore kit, or the fact that I have bigger jets in the 78 carbs that I have on my bike. What ever it is, I'll not complain.