Hard to start when cold

[Duane Ausherman]

When I crank her with the choke fully engaged, I get no spark. Seems that the choke is too effective. I get spark with no choke, but need some choke to get 'er lit.

My plugs are relatively new (4 months) and the plug wires & caps were new a year ago.

You have an ignition problem. The choke should have no affect on the spark of a healthy ignition system. Don't even bother to test the coils, just replace them.

A coil set is only $50-$70 and they are good for 10-15 years, often longer. In the worst case, that is only about $.50 a month for ignition and usually only half that. How much is it worth the go through the hassle that you now have?

For other readers, if you haven't replaced your coils for 15 years, or don't know, now is the time to replace them. Just do it.

It is "nice" when coils just fail completely, but so often that isn't the case. The labor in my shop was too great to bother with using old coils.

Oh, did I mention to just replace them?

[Manfred]

Duane,

When I said "spark", I was referring to the engine firing. Don't know if it's actually lack of spark or bad fuel mixture. Would a bad coil also cause problem starting a hot engine? My bikes starts immediately when hot - but it suddenly die at idle when hot once in a while.

I have read on an airhead forum that needle jets, jet needles, and gaskets on old carbs are a sure thing to improve operation - not expensive either. I'm not opposed to replacing the coils - don't want to do it if that isn't the problem.

Also, any thoughts on using a Harley coil, as advocated here? http://www.advrider.com/forums/showthread.php?t=497014

[Duane Ausherman]

To use the term "spark" means that you have removed the plug wire and placed it on a plug against the head/case and observed a fat red/yellow spark.

That is about step #1 in any diagnosis procedure of this type symptom. To check for fuel, just remove both plugs and drip in a few drops of raw gasoline, replace the plugs and fire it up. Does it then start easily for a few strokes and die as it runs out of fuel? If so, then when it won't start in the cold, it is lean, or completely starved.

Just about any defect has simple easy tests that will show up the failure. Learn and perform them. Operate from a basis of science and avoid the "shot gun" appraoch. You will save time, money and frustration.

[Manfred]

Thanks, Duane. I should have been more specific in my initial post. The bike is warm right now, having returned from a nice ride about an hour and half ago. I pulled one spark plug at a time the bike started on one cylinder - the left one easily with a steady idle and the right one not so easy with a desire to die. The sparks on each plug look weak to me - not fat at all and barely visible in the light of my open garage. The right plug has black - like too much fuel - on the side opposite the gap. Good brown around the gap. The left plug looks good and brown all around.

When she is cold, I will see what fuel in the cylinders does.

[Manfred]

Update - I took the bowls off to check the float needles, and measured the amount of gas in each. The right bowl had nearly 30mm while the left was just over 25. I adjusted the right to match the left. She was nearly cold and started up fine.