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good luck and if that doesn't work then try longer and locate someplace you know is well protected

and don't be the least bit afraid to break out the wire gauge drill set and open the tiny vent hole a bit larger


this may sound crazy but after I found the sweet spot for my vent

it got just a bit better when I slash cut the end of it

borderline voodoo if you ask me

I don't know if that one picture actually shows the melting ice off that intake runner

that was on a 50 degree day after a 5 minute heat soak

guess how much faster that bike is on a good cold day than it is during 100 F degrees ambient

amazingly enough the fuel mileage becomes more phenomenal the colder it gets too



I really have to wonder if many people tinkering with many of these japanese carbs limit their tuning efforts to strictly the following:

1) main jets

2) idle jets

3) float level

4) needle (not the float needle but the painful ones to tinker with in the slides) jets


if that is the limits of your tuning efforts

you'll only be lucky if you change the intake and exhaust and manage to have a decent running bike

heck........ I've never heard of anyone changing the air filters and exhaust pipes saying anything about changing the slide cutaways, emulsion tubes, or air bleeds yanno...... carb tuning junk like replacement, soldering and/or redrilling, filing... etc

much less getting ugly on the low speed idle and transition discharge holes

and really...... it can take all of that and more

no shame in it, many tuners are simply stuck at a compromise if off the shelf and readily available tuning bits don't make theirs sweet
 

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Discussion Starter #22
Finished downsizing the jets to 115's, dropped in new plugs ran a speed test up the street. Chop the Plugs and they look much better, mid-range and high end ran good but just a tad boggy on the bottom end. I'll adjust the air jet later this week and sync the carbs. That should take care of the bottom end. I took the bike for a 50 mile loop ride tonight and it ran much better.
 

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so i cut my fuel bowl vent tubes so they were more of less hidden. That fixed my issues above 50mph. It makes sense to me how those tubes hitting turbulent air could cause a pressure issue in the bowl, but i would have never thought that it was enough to effect the running of the bike. but it totally did. thanks for that recommendation!
Shaun
 

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hey thanks for not painting me with the bucket of "crazy paint"

glad that helped

you may end up with even better results by actually enlarging the internal hole size of the vent nipple into the carb
 

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One way to tell if your needle jets are too small is to remove the mains and make sure the engine dies when you give it full throttle. If it doesn't die, then your needle jets are restricting your main jets, and going any bigger on the mains doesn't do anything.
 
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