The BIGGEST hesitation I have ever experienced

I'll try to check the coils today and see what voltage they are getting and their resistance. Will post findings.
Carbs still off so I will check by blocking the air passage as you suggested.
Thanks,
Ken

Click on image to enlarge view.]



Good Luck!

I have done the above on all the carbs and all of the passages show good flow and, as much as it is possible to tell using carb spray, they all flow equally, comparing carb to carb.
Thanks,
Ken

idle circuits clogged

No, Please read the other posts. Idle circuits cleaned and tested.
thanks
Ken

When u get the cargs on try connecting a wire from the batt. to the coils and drive it. See if the voltage to the coils rises and drive it to see if the hesitation goes away. If it does, find the coil mod in this forum and follow the steps. I think it's listed under "voo doo magic":huh: :huh: , just kidding.

I thoroughly agree with the pilots going to 20. After that you probably need to rejet to a bigger main. If thats not the problem... I've seen this in other bikes and the problem is a loose timing change that jumps a cog on the cams. The bike will still run but it will hesitate and won't rev past about half way through the rev range. This may not be the case though because I think if your off one cog on this motor it will hit the pistons against the valves. To test put a set of vacuum gauges on it and see how much vacuum its pulling, a low number would mean that its off. If you don't have a vacuum gauge pull the cam covers and check the cam timing that way. I believe you said you have a manual so it should say how in there. Go with the jetting change first though. It sounds more like an air fuel problem since pulling up on the choke makes it better. What elevation are you at?? What do your plugs look like?? do you have pictures??

...Coil mod... :laugh: :woohoo: :laugh:
You got 13+ volts at those coils???

No seriously though, man, your running the bike real lean.

As per suggested...
1 size up on the pilots, then tune your air screws.

If everything is as clean as you say, then turn ALL your air screws about 1/2 turn at a time, at the same time.
Blip the throttle half. If the revs fall down below the idle rpm add more air (counter-clockwise), if it hangs slightly above add more fuel (clockwise). Turn them all in equal increments. Afterwards, you can turn them 1/4 or so either way listening for highest idle.
This I find is the best way to get a nice quick off idle response.

Needle clip on 4th slot down.

Main should be around a 115 to prevent the power curve from arcing down after half throttle.

You will have to experiment with mains/needle for best power delivery, then your done.

DONE. Like dinner.

Cheers!

TeK9iNe wrote:

...Coil mod... :laugh: :woohoo: :laugh:
You got 13+ volts at those coils???

No seriously though, man, your running the bike real lean.

As per suggested...
1 size up on the pilots, then tune your air screws.

If everything is as clean as you say, then turn ALL your air screws about 1/2 turn at a time, at the same time.
Blip the throttle half. If the revs fall down below the idle rpm add more air (counter-clockwise), if it hangs slightly above add more fuel (clockwise). Turn them all in equal increments. Afterwards, you can turn them 1/4 or so either way listening for highest idle.
This I find is the best way to get a nice quick off idle response.

Needle clip on 4th slot down.

Main should be around a 115 to prevent the power curve from arcing down after half throttle.

You will have to experiment with mains/needle for best power delivery, then your done.

DONE. Like dinner.

Cheers!

my bike, 1015cc ported and cammed, never hesitates with no filters at all, never. I used a 112 jet and 17.5 pilots and it never hesitated. Shouldn't be any reason to change the clip, once u get people doing that it's more confusion and problems with jetting. I have seen where spark was weak and choke helped it run better. He seems to be aware of the passages in the carb and says they are clean. If it has no power it may be the timing and a compression test is in order. If air spits out the carb at the end of the intake stroke, timing needs to be checked.

nads.com wrote:

TeK9iNe wrote:

...Coil mod... :laugh: :woohoo: :laugh:
You got 13+ volts at those coils???

No seriously though, man, your running the bike real lean.

As per suggested...
1 size up on the pilots, then tune your air screws.

If everything is as clean as you say, then turn ALL your air screws about 1/2 turn at a time, at the same time.
Blip the throttle half. If the revs fall down below the idle rpm add more air (counter-clockwise), if it hangs slightly above add more fuel (clockwise). Turn them all in equal increments. Afterwards, you can turn them 1/4 or so either way listening for highest idle.
This I find is the best way to get a nice quick off idle response.

Needle clip on 4th slot down.

Main should be around a 115 to prevent the power curve from arcing down after half throttle.

You will have to experiment with mains/needle for best power delivery, then your done.

DONE. Like dinner.

Cheers!

my bike, 1015cc ported and cammed, never hesitates with no filters at all, never. I used a 112 jet and 17.5 pilots and it never hesitated. Shouldn't be any reason to change the clip, once u get people doing that it's more confusion and problems with jetting. I have seen where spark was weak and choke helped it run better. He seems to be aware of the passages in the carb and says they are clean. If it has no power it may be the timing and a compression test is in order. If air spits out the carb at the end of the intake stroke, timing needs to be checked.

JUst noticed compression is good on this engine. It should not be so lean it only runs on choke. Something is not right here. Are the needles stock?

To nads and every one else who responded with there suggestions and with offers of help, I would like to thank all of you.
Not having any pilot jets at hand, I took out my old set of jet drill I've had since the 60's and took a stab at resizing the stock 17.5 pilots and drilled them out to .030". I reassembled the carbs and installed them on the engine.

With fingers crossed and fuel and full choke on I hit the starter. Heaven!! started on the first little pressure put on the button and happily idled at about 2000 rpm cold. I shut off the choke as soon as the rpm started to rise and she then dropped to a steady 1200rbm idle. A little turn on the idle adjuster an she was now happily purring along at 900 rpm.

I pushed the bike out side for the real test. Having never making it past my mail box before either stalling or needing to slip the clutch at 5000 rpm to keep from bogging out, away I went. This time she accelerated away as sweet as can be. I only did a short five mile loop as the temperature here was in the mid 20 degs Fahrenheit.

So for so very good. When the tempature comes up into the 30s I will try a longer loop to see if getting the engine hotter causes any need for further adjustments, but for now I'm very VERY happy with the performance I have. So happy that today I made arrangements with my painter do repaint all the fiberglass body work.

Once again thanks for the great response from this group
Ken Smith

timebomb,
Altitude 500ft. mains 117.5 needle clip 4 down
Thanks,
Ken