WOT...bog.
- daveo
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WOT...bog.
20 Jun 2016 11:08
Had a chance to open it up on some long country roads outside of town.
My couple feeble attempts at WOT, the bike accelerated great to 3/4 throttle, then it bogged down like it was running out of gas.
The fuel pump is adjusted to start before 1/2 throttle, and ends at the 3/4 (recommended) setting, but that shouldn't impact the situation, if I'm thinking straight.
I did not set the vacuum fuel petcock to the prime setting for that ride, but am not sure if that would matter anyway. Wondering if the fuel demand was greater than the petcock allowed to pass. Anyway, I have a set of 135 main jets coming, and plan to try them in there next time.
Thoughts for consideration?
My couple feeble attempts at WOT, the bike accelerated great to 3/4 throttle, then it bogged down like it was running out of gas.
The fuel pump is adjusted to start before 1/2 throttle, and ends at the 3/4 (recommended) setting, but that shouldn't impact the situation, if I'm thinking straight.
I did not set the vacuum fuel petcock to the prime setting for that ride, but am not sure if that would matter anyway. Wondering if the fuel demand was greater than the petcock allowed to pass. Anyway, I have a set of 135 main jets coming, and plan to try them in there next time.
Thoughts for consideration?
1982 KZ1100-A2
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- SWest
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Re: WOT...bog.
20 Jun 2016 11:32
Mains could be too big. Throttle chops will tell that.
Steve
Steve
Z1b1000 1975 Z1b
kzrider.com/forum/11-projects/598262-kz-...-will-it-live#672882
kzrider.com/forum/2-engine/597654-poser?start=240#704229
kzrider.com/forum/11-projects/598262-kz-...-will-it-live#672882
kzrider.com/forum/2-engine/597654-poser?start=240#704229
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- daveo
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Re: WOT...bog.
20 Jun 2016 12:10 - 21 Jun 2016 06:29swest wrote: Mains could be too big. Throttle chops will tell that.
Steve
Thanks Steve. I've read about the plug chop method, but haven't actually tried it. Especially unsure the process in this situation.
I prefer swapping jets, having been idiot-proof so far.
132.5 were last installed to stop (lean condition) persistent deceleration pops with 130's, so in my mind the mains may be too lean for the increased air mass beyond 3/4 throttle.
1982 KZ1100-A2
Last edit: 21 Jun 2016 06:29 by daveo.
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Re: WOT...bog.
23 Jun 2016 06:39swest wrote: Mains could be too big. Throttle chops will tell that.
Steve
With 135's the hesitation bog remains, but is less noticeable. Plug color is getting better.
Anyone know of a source for velcro grips? :whistle:
I'm going bigger...
1982 KZ1100-A2
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Re: WOT...bog.
24 Jun 2016 21:19On mine, decal pops were from lean pilot jets not mains. I do know too rich on the mains will make it bog at WOT.daveo wrote:swest wrote: Mains could be too big. Throttle chops will tell that.
Steve
Thanks Steve. I've read about the plug chop method, but haven't actually tried it. Especially unsure the process in this situation.
I prefer swapping jets, having been idiot-proof so far.
132.5 were last installed to stop (lean condition) persistent deceleration pops with 130's, so in my mind the mains may be too lean for the increased air mass beyond 3/4 throttle.
1979 KZ-750 Twin
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Re: WOT...bog.
24 Jun 2016 22:23bountyhunter wrote:On mine, decal pops were from lean pilot jets not mains. I do know too rich on the mains will make it bog at WOT.daveo wrote:swest wrote: Mains could be too big. Throttle chops will tell that.
Steve
Thanks Steve. I've read about the plug chop method, but haven't actually tried it. Especially unsure the process in this situation.
I prefer swapping jets, having been idiot-proof so far.
132.5 were last installed to stop (lean condition) persistent deceleration pops with 130's, so in my mind the mains may be too lean for the increased air mass beyond 3/4 throttle.
Thanks for the input. Size 20 pilot jets (w/original air jets) took care of the decel-pops, but I still get ping sometimes when it is hot outside (90 degrees F) here, and I'm not giving enough throttle on pull away with regular fuel. The motor idles best with pilot screws at 1/8 to 1/4 turn out.
Bigger main jets arrive today, and will see what happens with that soon. I love the easy access to the main jets behind the bowl drain caps, but the bowls will have to come off to replace the pilots.
You may be right about the main jet size direction needed, but so far I've gained an improvement with each size increase. The theory I have with the bog is that the pump stops injecting fuel at 3/4 throttle, and the main jet needs to be large enough to pick up the slack the rest of the way open. I hope to install the new mains later today, which I anticipate will prove-out the situation one way or the other.
1982 KZ1100-A2
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- SWest
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Re: WOT...bog.
25 Jun 2016 05:19
Z1b1000 1975 Z1b
kzrider.com/forum/11-projects/598262-kz-...-will-it-live#672882
kzrider.com/forum/2-engine/597654-poser?start=240#704229
kzrider.com/forum/11-projects/598262-kz-...-will-it-live#672882
kzrider.com/forum/2-engine/597654-poser?start=240#704229
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