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post #1 of 10 (permalink) Old 02-21-2014, 05:46 PM Thread Starter
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Carb jets

What are all the possible parts in the carburetor that are adjustable for air/fuel flow? As far as I can see, the two Jets housed in the drain section of the carbs are just screw-in. I only see the pilot jet as an adjustable part.

Is there something I'm missing? I ordered 40/140 Jets in anticipation of a full ear shave, although I plan on retaining a stock exhaust.

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post #2 of 10 (permalink) Old 02-21-2014, 06:45 PM
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....seek....and you shall find......the search engine is your friend....

...there are only about 124 posts on this subject....thanks....



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post #3 of 10 (permalink) Old 02-21-2014, 07:14 PM Thread Starter
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Did just that. Apologies for laziness. Didn't intend to quasi-troll. Seems the two Jets are snagged in, the long long needle is shimmed to allow for more clearance, and the adjustable screw... Well I'm confused about that. Does it only affect idle, or is it utilized throughout the rpm and throttle range?

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post #4 of 10 (permalink) Old 02-21-2014, 07:43 PM
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If you look for "Ear shave"...the entire proceedure is outlined, also explaining what and why...the long needle is to be shimmed if needed, and thats explained as well....if you are not going to change the stock exhaust, there should be no need to rejet or reshim after an earshave....yin/yang...you only need to rejet if you match your increased air intake with a more open (less restrictive) exhaust....the increase in air, without a proper out, is just that....more efficient, but no need for more fuel...all you may need to do is to adjust the idle mixture screws on each carb (counterclockwise) to allow a bit more fuel at idle and prevent popping...

If you kept stock intake...then added less restrictive exhaust, similar situation....all youd be doing is evacuating gasses easier...no rejet needed...

If you do BOTH, then the engine will require more fuel, or will run very lean....going up one jet matches the intake/exhaust mods. Performance will increase, but efficiency will suffer....

Sorry if i sounded like a hardass, but lately new folks been asking countless questions that have been answered countless times here. Im attempting to curtail that kind of thing....nothing personal...



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post #5 of 10 (permalink) Old 02-21-2014, 08:01 PM Thread Starter
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I understand. I've been on many forums over the past 14 years, and I know the Feeling you get when you see posts like mine. I tend to disagree on the subject of air movement.

Your claims are based on the assumption that at any given time, intake volume is ultimately limited by the exhaust. I say this, because I believe if you upgrade the intake, you will more easily pass air through the engine (remember, you never gain horsepower, you just free it [mods allow the engine to perform the same task with less energy]) and I don't believe the exhaust is restrictive enough for negate the increased intake performance. I would agree that upgrading the exhaust will allow more free air passage.

Writing this on my phone and watching TV and sipping some captain, so apologies if this post is sub-par or doesn't make complete sense.

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post #6 of 10 (permalink) Old 02-21-2014, 08:10 PM
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No problem....and no, I dont say these things from assumption, I never assume...I only speak from what Ive experienced over the years...and Ive been modifying motorcycles and cars since around 1970, and Ive also raced cars and bikes....by increasing intake, youre only making the engine more efficient (if set properly) and may even see a gas milage increase...you may experience some low end pep increase, but ultimately not throughout the entire RPM range...to achieve any real HP increase, you need to also modify exhaust....yin/yang...zen motorcycling...



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post #7 of 10 (permalink) Old 02-21-2014, 08:18 PM Thread Starter
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Oh, I'm too grumpy to debate. I concede, but beware, I may decide to discuss this further.

I need to say, also, that I mean no disrespect when I voice my opinion. I certainly respect everyone's experience and merely offer different insight.

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post #8 of 10 (permalink) Old 02-21-2014, 11:39 PM
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After my earshave with stock exhaust the pipes began to yellow within 200 miles until I increased the slow jet size. Every bike is a tad different but for my bike rejetting was badly needed after the earshave.

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post #9 of 10 (permalink) Old 02-22-2014, 08:50 AM
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Didn't need jets for mine. If anything, it's a tad rich still.

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post #10 of 10 (permalink) Old 02-22-2014, 09:26 AM
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Mine needed 140/40's.had a flat spot from about 4500 and up

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