Help with carb sync

[glstine]

Is it firing on all cylinders?

I would take a spray bottle of water and spray some on the exhaust header pipe, if it is running properly the water will sizzle and evaporate. A pipe that is not firing will cause the water to basically roll off. If your not firing on all cylinders I would try cleaning the carbs again.

You mentioned that you turned the engine without the cam tensioner. Did you verify that the timing marks are aligned and that the cams are aligned. It could have skipped a tooth when you turned it.

It's hard to tell from the pictures but I would expect to see a discoloration (blue/brown) in the first couple of threads on the spark plug if the bike is running properly. I seem to remember chef1366 commenting on this discoloration before. The insulator should be tan and you should see discoloration on the first couple of threads if the mixture is correct.

I did check the timing marks afterward and they were per spec. The plugs are new so I don't think they would have been used enough to discolor up the threads. I did check for firing on all cylinders by pulling the plug caps off one at a time and checking for change in rpm's.

[chef1366]

If you have the carbs all clean and set than it's ignition.

[glstine]

If you have the carbs all clean and set than it's ignition.

So what do I check and how do I check it? Timing marks line up and I have spark on all 4 cylinders. I don't know what else to check.

[almarconi]

You say the timing marks line up, did you take the valve cover off to see if the timing marks and the cams line up correctly. Did you count the correct number of links on the cam chain. It is very easy to be off a tooth and not even realize it.

[glstine]

You say the timing marks line up, did you take the valve cover off to see if the timing marks and the cams line up correctly. Did you count the correct number of links on the cam chain. It is very easy to be off a tooth and not even realize it.

Yes, counted them multiple times to make sure.

[almarconi]

How about plug caps and wires? Did you measure the resistance of the caps and wires to rule these out? If the caps are OK try cutting a 1/4" off the wires and reinstalling the caps.

Air filter clean and airbox sealed?

Did you inspect your slide diaphragms to make sure there were no pin holes? Did all the jets and other brass parts match. There should be numbers etched on all the parts. I rebuilt a set of carbs one time and one of the cylinders would not fire, turns out one of the jets I used from a rebuild kit was not the correct one.

It's sometimes difficult to diagnose problems without actually seeing the bike. Another option would be to try another set of know good carbs to see if you are having the same problem. Its common for fuel problems to look like ignition problems and vice versa so its takes awhile to get everything sorted out.

[glstine]

I measured the coil resistance, but I want to make sure I did it right. For the primary resistance I measured across the two incoming wires. For this I set the meter to 200 Ohms and just got a 1 on the left of the display. I switched to 20 kOhms and got 1.04 on both coils, so I guess that is 1040 Ohms compared to the 3.5-4.5 Ohms the service manual says, I'm guessing I'm either doing something wrong or the coils are toast.

For the secondary measurement I measured across the spark plug caps and got 26 and 27 kOhms, service manual calls for 35-38 kOhms. So if I measured correctly, I guess I need to get new coils.

I have dielectric grease in the connectors, I am assuming this should have little to no effect on the readings.

[almarconi]

The meter I have is auto ranging. When set to resistance you get a reading in the 3-5 ohm range for the coils.

You should measure the primary resistance between one of the terminals and ground. Use one of the bars on the coil for ground or a suitable chassis ground. The secondary resistance should be measured with one probe on the spark plug wire and the other to ground. Some coils may test OK cold but fail when warm. I would also remove the cap and measure the cap for its resistance.

Try remeasuring and report back.

[chef1366]

If they do test bad I have a good pair.

[almarconi]

If they do test bad I have a good pair.

Chef is there a part you DON'T have

[glstine]

The meter I have is auto ranging. When set to resistance you get a reading in the 3-5 ohm range for the coils.

You should measure the primary resistance between one of the terminals and ground. Use one of the bars on the coil for ground or a suitable chassis ground. The secondary resistance should be measured with one probe on the spark plug wire and the other to ground. Some coils may test OK cold but fail when warm. I would also remove the cap and measure the cap for its resistance.

Try remeasuring and report back.

I get nada when measuring between terminal and ground and spark plug wire and ground (I tried several different grounding locations too). I do get 6.0 to 6.25 kOhms on the spark plug caps (year old NGK 5kOhm caps)

[Steve]

Chef is there a part you DON'T have

If there is, I'll bet it's shaft-related.

.

[chef1366]

Chef is there a part you DON'T have

Alot less if people would buy them
Gotta pay for a motor.

[glstine]

Chef, sent you a PM.

[almarconi]

Well it sound to me like the coils are bad.

Here is an article that describes how to measure coils with your type of meter. The method is similar to what I described.

http://www.ehow.com/how_5770664_check-resistance-motorcycle-ignition-coil.html