carb jets

H

highstrung74

New Member
i cant find the site but i remember one of the sponsor having a "jet set" that had about 12 diffrent sizes for 14.99....does any one know the site cuz i cant seem to find it...lemme know if you can link me to the site thanks again
never mind found the site...
 
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You could buy a lot of solder for $15. bucks.
Many of us never bother with jet sizes. First place they're too nebulous. What one vendor calls a #65, another will say it is a #68. There doesn't seem to be any dependable standardization.

If you can solder and work a pin vice, you can solder the jets and re-drill to fine tune the carburetor to your specific needs. You'll need a means of soldering, either gas or electric and a set of micro-drill bits, oh, yeah, and about 20 cents work of solder. And you don't end up with a bag full of jets you can't use because they're too big or too small.

Tom
 
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I like having tons of jets in my stash drawer in my toolbox tho...

The problem with the jets most places sell for these is that they're not very accurate at all, you can order 3 jets of the same size and have 3 different size jets so you got 2 real chioces... Solder and redrill your exisitng jets or buy genuine namebrand jets... and the jet sizes aren't exactly the same from brand to brand either... some are sized in milimeters (fractions of a milimeter actually), some in thousandths of an inch, and then some are sized by gallons per minute, liters per minute etc... every carb company has their own method...

When you solder and drill your own all you need is a soldering iron, some solder, and a set of tiny drill bits, there are people who mae up jetting bit sets on ebay. You can drill them by hand with a pin vise, or if you got a Really steady hand, they can be chucked into a small drill or dremel with a finger chuck. I'd recommend the pin vise if not experienced here... Usually these drill sets cost about what 3 or 4 jets cost so it's generally cheaper to get the drill set, a soldering iron, a small roll of solder, and about 15 minutes of yor time...
 
here is all you need along with a soldering method and a tiny bit of ine wire size solder.

all of my NT carbs had a #70 wire gauge bit size orifice.

In my elevation and with my engine set ups a #73 or #72 wire gauge bit has drilled all mine to run very good.

http://www.widgetsupply.com/product/drill-bit-twist/BLU01.html


mThis is where I get most of my tools for port work on the jugs and bits for drilling carb jets, best fbang for the buck pla e Ive found on these items.
 
Here ya go. This is a wire gauge drill index and a pin vice.
Mapbike uses about the same size of drill that I've found works for me. That's odd because I'm at 6000' above sea level.
But, hey, whatever works, right?

Tom
 

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2door said:
Here ya go. This is a wire gauge drill index and a pin vice.
Mapbike uses about the same size of drill that I've found works for me. That's odd because I'm at 6000' above sea level.
But, hey, whatever works, right?

Tom
Click to expand...

Yeah I know that is wierd about the jet sizes being so similar for me here at 1,250' A.S.L. and you being @ 6,000'

All I know is that my plug color is good, and I have just a slight amount of 4 stroking at low throttle without a load on the engine and no 4 stroking under throttle from about 10mph all the way up to top engine rpm.

I just try to make sure if anything I'm leaning on the edge of rich rather than lean since I make long high rpm runs at times and don't want to run the engine any hotter than necessary here in the hot dry Texas summers.
 
mapbike said:
here is all you need along with a soldering method and a tiny bit of ine wire size solder.

all of my NT carbs had a #70 wire gauge bit size orifice.

In my elevation and with my engine set ups a #73 or #72 wire gauge bit has drilled all mine to run very good.

http://www.widgetsupply.com/product/drill-bit-twist/BLU01.html


mThis is where I get most of my tools for port work on the jugs and bits for drilling carb jets, best fbang for the buck pla e Ive found on these items.
Click to expand...

Cool... I just bought me a couple sets of these from that link just now.. Mine's definitely ready for some re jetting now that it's almost done with it's second tank of gas
 
Davezilla said:
Cool... I just bought me a couple sets of these from that link just now.. Mine's definitely ready for some re jetting now that it's almost done with it's second tank of gas
Click to expand...

oh yeah, she'll come alive when you get the jet size dialed in, very little blubbering and a nice smooth buzz right on down to the taco shop......!

Myself I reduce jet size befors I ever even start the engine for the first time since I've found what seems to be a zweet spot that has worked on all my engines so far.

No doubt widgetsupply is the best bang for the buch on these items, I haven't found a better deal anywhere else, bought my first set from them in 2010 and a pile of other odds and ends, they ship quick and have a dang good price on all their stuff.
 
Wish I'd have had access to them back when I was building R/C planes. Some great tools for modeling.

By the way I just noticed those drills are on special right now. I hope Dave got the sale price.

Tom
 
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Yeah, mine does tend to blubber a little bit on top then clears up when I back off the throttle a little bit so I'm definitely on the rich side with it still...

I've used these bits as small as #80 on other jobs and checked them into my dermel to do the drilling at the lowest rpm setting. then I got some bits that are so small I need to keep them in their paper bag to keep them from getting lost or accidentally bent or broken, drilled a .010" hole thru a piece of 1/8" brass just to see if I could do it without breaking the bit, same thing, chucked into a dremel with a small finger chuck installed, then just held the tool upright on it's slowest setting and just let the weight of the dremel do the work.

Anyway, I decided to get a few of these bit sets to keep here at the shop since I got some really small bits but none of them are organized, they come in packs of 5 in these tiny paper envalopes and once they get mixed up or put in the wrong envalope it's near impossible to figure out which one is which size without checking every one with a micrometer. I'm also most likely missing the "in between" sizes that I'll need for jet drilling.
 
2door said:
Wish I'd have had access to them back when I was building R/C planes. Some great tools for modeling.

By the way I just noticed those drills are on special right now. I hope Dave got the sale price.

Tom
Click to expand...

Oh yeah they have a load of smalls for modeling and all kinds of craft type work.

I stumbled across the site back in 2010 and I've enjoyed finding it for sure, I've found the very same bit sets they sell at other site for like $20 and widget sells them for a small fraction of that and everything I have bought from them has been excellent quality.

That is why I share this link any time someone gets in a conversation on here about porting jugs or needing to change jet size.

all kinds of goodies at a great price is my kind of place when the products do what they should.
 
mapbike said:
Oh yeah they have a load of smalls for modeling and all kinds of craft type work.

I stumbled across the site back in 2010 and I've enjoyed finding it for sure, I've found the very same bit sets they sell at other site for like $20 and widget sells them for a small fraction of that and everything I have bought from them has been excellent quality.

That is why I share this link any time someone gets in a conversation on here about porting jugs or needing to change jet size.

all kinds of goodies at a great price is my kind of place when the products do what they should.
Click to expand...

No kidding... After making a purchase there I had to restrain myself from pulling out the credit card and buying more goodies after seeing some of the other stuff they sell there...
 
Davezilla said:
No kidding... After making a purchase there I had to restrain myself from pulling out the credit card and buying more goodies after seeing some of the other stuff they sell there...
Click to expand...

Yeah I have that weakness myself.......

they take pay pal which is my preferred way to buy online and it's so dang easy..

I dropped about $36 their way yesterday on several different size and shaped rubber grit polishers, 1/4" drum sanders and a few other odds and ends, if you spend at least $30 then they ship for free and if sanders and stuff like that is what someone orders they can get a big pile of stuff for $30.

These places make me feel like a woman with a sack full of hundred dollar bills in K-Mart when it rings out over the intercom... " Blue Light Special" on isle 4, all womens goods marked down 80% off for the next 15 minutes.....

Picture this for a moment............ Oh Yeah when I find good deal on the parts and pieces I use or like, it's hard to restrain myself...LOL

My wonderful wife tells me as she laughs at me all the time that I wouldn't know what to do if I didn't get a package in the mail almost everyday....!

I'm not a big spender, but I do buy a lot of smalls and odds and ends to use when tinkering with my bike stuff, the wife says I have that ADD mess and that's why I do what I do...LOL!
I am fairly high strung and never been good at taking crap off of man or machine, but as I get older and by the grace of the Lord I continue to get better and tunnel my energies toward my faith, family and hobbies in a positive way and so I tend to hoard junk related to my hobbies as a pass time.

Widget supply and places like them who offer good bang for the buck is good medicine and I only buy what I can actually use so nothing is really waisted.

The terrible and horrible murderous to the wallet ebay addiction is real folks.... and its so easy to contract it, be afraid.... be very afraid....!

going-crazy-1.jpg
 
Yup... I got the ebay addiction as well as Harbor freight... everytime we drive by the Harbor Freight my wife just looks at me and says "No"... but I can go in there and look around for hours putting stuff in the basket as I go, then seeing something else I want so I'll take stuff out of the basket and get that instead... then heading toward the checkout line I'll start thinking to myself.. "well, that other stuff isn't That much more so I'll go back and throw everything I took out of the cart earlier back in before finally making it to the checkout line... then if the line is long or slow... or both, sure enough something else catches my attention and I'm off to decide whether to get it this week or want til next time I stop by...
 
Im trying to wrap my head around this topic, as there's noo thread describing the theory of jetting in a detailed manner...I've never soldered before, would i be better off buying a set of jets???

And if the stock jet for these engines is too big, why would we need to "re-drill" it out to an even bigger diameter? Im trying to understand the fundamentals of jetting : ) thanks
 
You'd probably never want to "drill out" a stock jet. They are typically always too big to start with.
When we talk about drilling we're talking about redrilling after the jet has been soldered closed.

Finding the right jet orifice size is a study in experimentation. There seems to be no 'silver bullet' or one-size-fits-all. Different carburetors/engines/rider weight and style/ terrain/gasoline/oil etc. all play into what will perform best.

Start small and move up. That means solder the jet closed, redrill with a small size and ride the bike. You'll know quickly if you're in the ball park. You'll usually have to redrill a couple of times, or more, until you find what works 'for you'.

You will need to learn to solder and have the tools to do it correctly. They aren't expensive but do take a little practice to master.

I did a video tutorial on jet resizing. I'll post it here for you, if I can find it again.

EDIT: Here's that link > https://www.youtube.com/watch?v=GcYd97t-6ns

Tom
 
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When I solder in the jet I don't fill the hole completely. I just add enough solder to close the hole some, then drill out to the size I need.
 
Ninja Turtle said:
When I solder in the jet I don't fill the hole completely. I just add enough solder to close the hole some, then drill out to the size I need.
Click to expand...
Right. There is no need to fill the jet completely full. You're only concerned with the orifice size. The drilling process would be difficult if you had to drill the full depth of the jet body. That's why, in my video, I show drilling from the bottom of the threads upward. The original hole acts as a guide to get the drill bit centered.

Tom
 
thaaaank you, its all coming together now..

You said start from the threaded side & go upwards,

Now if you dont drill the full length of the jet body, how does one know where to stop?
 
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