hi all, just replaced my 12mm bing with a 14mm. now matches 14mm intake. also have 18 tooth sprocket that will be installed later this week. it seems to be bogging alot. it has a # 58 jet in it. does this sound right? i did a plug chop with a new plug, and it seems good. a little on the dark side. any suggestions would be great.should i adjust the throttle needle? would that help???
Paul,
Describe "bogging" in detail. Speed, throttle opening etc.
Same for plug chop.
Ron
Adjust the slide needle, try moving it up a notch, then down a notch from the original location before replacing the main jet with a bigger one. This is time consuming because every adjustment you make to the carb will require a test run and a plug reading. I'll tell you what I've got in mine, it's a 2hp Cobra with a 14mm carb and manifold. It's got a 68 main jet and a 2,17 needle jet which is set in the first notch from the top. I've removed the head gasket, 3 perforated metal discs from the intake ( Cobra's don't have the white plastic snorkle ), and drilled holes in the exhaust pipe insert, so be warned, this may not work on yours unless it's set up like mine but it should get you in the ballpark.
ok i screwed up...... theres a # 68 jet in there. i already removed three layers from air box, and removed head gasket brian.( recommended by you awhile back). here we go..... the throttle needle was on the second notch from top when i got the carb. moved it to first notch from top. still bogging.... ron whats happening is its hesitating when i give it gas.( i call that bogging). it still did it with the needle position change. it seems to be four stroking at top speed. so like freds guide says, i removed air box and test rode it. seemed to be better. by the way i did a plug chop after needle position changes,and air box removel. plug seems fine not too light, and not too dark....... i LITTLE tan in the center, but dark on the outside. do i need to go to the third position on the needle, and do a plug chop, or go down to a # 66 jet size?????? sorry to be so long. but its driving me CRAZY!!!! please help......
Interested in selling the Bing carb?
Paul,
I wish I could give you a simple answer, but I can't.
If it is four stroking at high speed, you most likely do need a smaller jet. I notice you seem unsure of this, if it starts four stoking, you get an immediate loss of power and a very distinct change in engine note.
I'll describe your other problem as hesitation off idle. Does this happen if you roll on the throttle more slowly? Do you have an idle mixture adjustment and if so, have you tried turning it in or out to see if that makes a difference? Does moving the needle from all the way up to all the way down make a difference? If so, what?
Sorry I can't be more specific but these are the tests I would run if I had the problem.
Btw, have you made sure your timing is right and your carb has no crud in any of it's passageways?
Ron
Move the clip to the bottom slot and try it, that's as rich as it'll go with that main jet. I would go to a larger main jet if that doesn't work. Have you done any exhaust modifications to it ? The engines been de-carboned hasn't it ? How many miles on it ? By the way, look at the porcelin part of the plug to read it, ignore the rest of it.
ron, brian, anyone please........ i have an update to this older post. i recently ordered the # 66 carb jet, and installed it today.this was because # 68 seemed to be making it bog at low speeds, and four stroking at high speeds. after replacing it with the # 66 jet. i took it for a ride, and was very happy at first with acceleration, no bogging at all. :), then got on it, and it started four stroking again :( . my question is this should i have went with the # 70 jet???? would that have been better? PLEASE HELP!!! I AM FREEKING OUT.................
HURRY!!!!!!!
Paul,
Relax, it has been scientifically proven that freeking out about ped problems significantly impairs your ability to operate and enjoy your ped. : )
It sounds like your smaller jet improved things somewhat, so going in the opposite direction would most likely make it worse.
Have you tried running without the air box and/or filter to see if you still 4 stroke. Often, as you increase rpm and the need for air, the existing set up will restrict the air flow enough to cause the mixture to richen up.
Try this and post results.
Ron
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