Carburetor Rebuild: photographic tour.

[Cinciride]

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Installed the carbs today.  Fired up right away and it is 40 degrees outside.  

I could not help but give the throttle a couple of quick twists, and it was quicker to rev, and quicker to settle too.

Off choke after warm up and a quick spin around the block demonstrated it was a little hesitant off idle.  I popped the plug caps off one side at a time, and found that it did not idle on the left cylinder.  A quarter turn of the air mix screw and idle was 500-600 RPM on right and left cylinder and off idle hesitation was gone.  One quick rip down the nearest 50MPH road and I found the bike pulling with authority past 65, 70, 75.  My last highway trip on this bike before the carb rebuild and It would cruise at 70, but was a bit of a dog when I got on the throttle to pass, and even acceleration to 70 was a bit labored past 55-60.  I can not wait until kinder weather settles in, and I can take it out to stretch its new lungs.  

A couple of things I will be keeping track of, once commuting begins in earnest again.  
1. Acceleration at highway speeds (not many highway speeds on my commute, but I may take the long way).

2. Mileage.  Pre carb rebuild mileage was 40 MPG.  

Thanks to all for the advice.  

Colby

[Bob_Roller]

Where do you have the idle set ?

I don't know how much truth there is to this, but 'they' say that the idle should be around 1000 rpm or so .

Reason, the timing chain area doesn't get enough lubrication at a low idle .

For what ever that's worth !!!!!

[Cinciride]

It will idle just over 1000 RPM.  It is just that when you pull one of the spark plug wires it drops to 600.  Both in place 1000-1200.  Not sure if this is how it is supposed to work.  

When I fired it up my son (10yrs old) was outside and he said.  Dad, that sounds great.  Much better than last year.  He knew I rebuilt the carbs, and was probably trying to make me feel good, but the engine does have more of a snap to it.  

[Barry]

It will idle just over 1000 RPM.It is just that when you pull one of the spark plug wires it drops to 600.Both in place 1000-1200.Not sure if this is how it is supposed to work.

That's exactly what you would expect when you short one of the spark plug leads to earth. 1200 RPM is getting a little on the high side though.  1050 is a good target.

[montmil]

... It is just that when you pull one of the spark plug wires it drops to 600.

Did you ground the removed spark plug cap while the engine was running?

IIRC, isn't running the engine with one spark plug terminal removed but ungrounded considered a no-no for the Airheads? Might somebody confirm or correct this thought?

[Barry]

I did wonder which is why I made a point of mentioning grounding the spark plugs.

Just pulling the plug cap is an absolute no no on electronic ignition bikes as it stresses the coil insulation by open circuiting the secondary winding which will then develop the maximum possible voltage it's capable of. That voltage will be something like 20-30,000 volts which is at least double what is normally required to spark the plug and possibly enough to break the coil insulation down or fry the electronics.

Even on points ignition it's still bad for the coil for the same reasons. The maximum voltage will be a little lower that's all.

The only safe ignition systems for "pulling the plug caps" are magneto ignitions which have a safety spark gap built in that arcs across before dangerous voltages are reached.

[Cinciride]

Might have had an amateur moment there.  I did have the plug cap in contact with the cylinder while I did it, but that was not on purpose.  Thanks for the info.  I will check the idle a little more closely next time I fire it up.  Cheers, colby.