Drilling out jets

I wonder if you could ream them out a bit with a torch tip cleaner kit available from a welding supply shop?

kpier998 wrote:

I wonder if you could ream them out a bit with a torch tip cleaner kit available from a welding supply shop?

It would have to be awful close or they wouldn't go through. I asked a guitar player if he could play it behind his back? Response was. "I'd play it out my ... if I could get it in there." Determination brother! Backstage at the afterparty chick asks ozzy what's the little tiny one for? Boy did she have a story! And a welt alongside her face. Is that twice bitten or what.

otakar wrote:

$10 for a pack of four jets. What exactly are we talking about here? :ohmy: The postage is half the cost of the jets.

Beats me. It's been a long time since I would hassle with the headaches for a part that cheap.

nads.com wrote:

Hey maybe you'll break something else in the process! lol.:woohoo:

Ain't that the truth!:laugh:

Dark... What exactly are you wanting to do this for / accomplish... More power...? :huh:

I must be missing something here... I can understand jetting for too lean, too rich, custom exhaust with pods thus rough idling, rough low/mid/high range responses etc... but more power gain, too what degree...

I have brand new Keihins and jets average no more than $4-5 each (mains & pilots) and a little more for needle jets. All in all, jets aren't really that expensive.

OMR

Well the bike is running very lean, i have NO power, and she idles very rough. There are pod filters on the monster, and strait header exhaust, and i am getting ready to baffle that. But yes, I want power, i get to a stop sign, and she can bairly cross the street because she has no power, so yes.I really need help figuring out what size needles i need and all of that. BTW i hate dealing with carbs,but some point in life i need to over come that....

BTW i hate dealing with carbs,but some point in life i need to over come that....... :laugh: Don't we all....

"Well the bike is running very lean, i have NO power, and she idles very rough. " .... There's a saying Lean is mean but too lean is NOT GOOD indeed!

Now I understand where your not speaking in the terms of obtaining more power (go fast power) but just in getting this motor to run correctly power... Yes, big difference, ok I get it now...

How about we start over where WE can help...
What carbs are we speaking of?
Data not in your profile so you may want to update this sometime (model, year, modifications etc...) .

If known, which jets do you presently have installed... Mains, pilots, needles etc...

What settings (number of turns out, float heights etc...) do you have these at now?

Does the motor smoke, if so which color?

Are you hearing pinging sounds when running at idle, mid throttle, WOT...?

What are the spark plug insulator colors and overall plug condition?

What are the conditions of your intake manifolds, possible leaks?

Valve clearances and ignition timing good?

Have you tried a different set of carbies just to see if it makes a difference, maybe the problems elsewhere...

NOTE: Yeah I know, who but a few has an extra set of carbies laying around....

Just a few things to consider first...

OMR

For initial pilot settings... ColorTune for you.... Worth the expense...

Your main jets have absolutely nothing to do with initial acceleration. They only come into affect in the last 20% of throttle opening. You have other issues you should be looking at. It may not even be your carburetors. (I am not saying it is not, but it MAY not.) You will have to change your jets about three maybe four sizes larger for sure just because of the mods you described, but your off the line laziness IS NOT due to your main jets.

Your main jets have absolutely nothing to do with initial acceleration. They only come into affect in the last 20% of throttle opening.

...

Very true... I only asked due to extreme lean conditions and total lack of power with no mention above dead stop lack of power. And to also find out exactly what he presently has in a combined carb configuration.

This is the jetting curve for the Keihin CR's... Obviously each carb is different where it falls in the range but the concepts should be similar just the same for most carbs.

remember manufactures of jet kits will put their own number on the jets, not an OE size. i've seen this with an older Dynojet kit. that's why i purchase all mikuni brand jets. at least you have an accurate baseline.

don't forget to write things down.....always a big help when changing exhausts or other things.

gershom wrote:

remember manufactures of jet kits will put their own number on the jets, not an OE size. i've seen this with an older Dynojet kit. that's why i purchase all mikuni brand jets. at least you have an accurate baseline.

I've been told this too, by many people. However, when it comes to actually measuring the jets, the jet number always corresponds to hundredths of a millimeter. I even called Dynojet to confirm, and the tech said quite emphatically, the jet sizes are hundredths of millimeters, just like on OEM jets.

This urban legend probably comes from drilled jets where the person drilling them doesn't remove the jet number stamp. I always grind the number off or stamp punch marks through the number.

However, having the same jet number and hole size does not mean two different shaped jets will have the same flow. If the jet is longer the hole will be more restrictive even though the inside diameter is the same. Also, how far down in the float bowl will affect the flow rate.

gershom wrote:

remember manufactures of jet kits will put their own number on the jets, not an OE size. i've seen this with an older Dynojet kit. that's why i purchase all mikuni brand jets. at least you have an accurate baseline.

don't forget to write things down.....always a big help when changing exhausts or other things.

This is very true. Dinojet uses the actual "measurement". Mikuni uses the "flow rate" Keihin uses "who knows what". I do the same thing I just switch to ALL MIKUNI jets, and that way I know where I am. With Mikuni jets the hole size is very close to the measurement when you are between about 95 and 125. once you go larger than 125 the hole is no longer the measurement size. I have gaged most of the Mikuni jet sizes with metric pin gages and know this for a fact.