Drilling jets

Those will work for most applications... Most metric jets are numbered in hundredths of a milimeter like for instance a #75 jet is 0.75mm so you would need to convert the milimeters into inch then to the wire gauge size which will work since there are several size conversion charts on the net you can download.
you can usually just find the jet size by pushing a bit thru to find which one fits the hole, then go up one size to drill it out and be just fine as well, you can always solder the holes shut and re drill if you do go too big so it will work either way...
 
Ok good, so I have enough range with those bits to go down far enough? Bigger bit numbers meaning the smaller the hole drilled. I was planning on matching the bit with my existing jet size and go down as you suggested. I'm running a 66 right now I believe, but still 4 stroking.

How do you solder the jet? Just get it hot with a torch and touch the solder to the hole?
 
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It should give you enough size options to get you dialed in, if you're still 4 stroking you can solder the jet shut and re drill it to the next bigger number size which will be the next smaller diameter.
If you do get stuck between sizes you can always get a set of micro drill bits in fractional or metric fractional sizes or if you're lucky, you can just get the individual size needed for the final tune if needed.
 
bits used to be a little cheaper, so I have both US & metric sets onhand

a small manual drill is also handy
 
Toothy;560991How do you solder the jet? Just get it hot with a torch and touch the solder to the hole?[/QUOTE said:
Yep, what I do is hold it with a needle nose vice grip & hover it right at the edge of the blue flame of a benzine bottle torch(the kind used for sweating pipe), 2 or 3 seconds is enough as brass is an excellent conductor of heat, then just lightly brush the solder to the hole. Make sure you use flux core solder or it may not stick, & not too much either, because the more you use will mean that much more you have to drill out.
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Toothy,
You don't need as much heat as a gas torch will provide. I use an electric soldering gun.
You should use solid core solder, not flux core, and I've always had good luck with either 60/40 or 50/50 solder. I like Nokorode paste flux.
The jet MUST be clean and oil free. I like to sand them a little with a 3M pad making sure to get any surface oxidation off leaving clean shiny brass around the orifice.

A pin vice is almost an essential tool for drill bits the size we're talking about. Don't try an electric drill. Run the bit by hand only.

Tom

EDIT: Sorry SuperDave. We were typing at the same time and gave the guy conflicting information. Just another example of "use what works for you" :)
 
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SuperDave said:
Yep, what I do is hold it with a needle nose vice grip & hover it right at the edge of the blue flame of a benzine bottle torch(the kind used for sweating pipe), 2 or 3 seconds is enough as brass is an excellent conductor of heat, then just lightly brush the solder to the hole. Make sure you use flux core solder or it may not stick, & not too much either, because the more you use will mean that much more you have to drill out.
Click to expand...

Thanks....I figured that would be the best way. I'll be going to a test area so it will be good to be able to use my cordless drill and torch in the back of my truck bed.

As far as price goes, that website is about the cheapest. I guess you need to proper chuck so I bought that too. Around $30 total. This hobby adds up, thats for sure!
 
2door said:
Toothy,
You don't need as much heat as a gas torch will provide. I use an electric soldering gun.
You should use solid core solder, not flux core, and I've always had good luck with either 60/40 or 50/50 solder. I like Nokorode paste flux.
The jet MUST be clean and oil free. I like to sand them a little with a 3M pad making sure to get any surface oxidation off leaving clean shiny brass around the orifice.

A pin vice is almost an essential tool for drill bits the size we're talking about. Don't try an electric drill. Run the bit by hand only.

Tom

EDIT: Sorry SuperDave. We were typing at the same time and gave the guy conflicting information. Just another example of "use what works for you" :)
Click to expand...

Thanks for the great info.
 
If you're stuck without a pin vise, I have had some luck chucking the jet in a cordless drill and running it onto the bit clamped in a hobby vise.
Be aware these bits break VERY EASILY and you need to be VERY CAREFUL drilling with them.
 
I agree with 2door, those microdrill bits break super easy so use a pin vise & hand drill. Go slow, be patient. It sucks having to wait another 3-5 business days shipping because you broke the only bit that will jet your carb correctly.

I tried a solder gun, after 20 minutes I gave up & grabbed a torch. Gas & flux core solder worked for me, electric & solid core works for 2door, both of us are happy with our results. Choose your blues & report back your news.
 
I'll second that as well, I got a set of cobalt bits that go pretty small (I think I may have some .010" bits in my stash somewhere) and they'll break just by looking at them wrong.
What I do to prevent breakage is use a keyless finger chuck on my dremel with an arbor to hold the bit and put the dremel in one of those drill press adapter kits for the dremel, run it at the slowest setting and lube the bit with Boelube, then I just push down very gently and it'll cut thru 1/8" of brass without too much risk of breaking. It can be done without the press attachment with the dremel but i'll use just the weight of the tool to push with and hold it as straight as possible, the press just does a better job at keeping everything straight, but freehanding it can be done with steady hands. I also have a few pin vises for the ultra fragile stuff.

For soldering, I use a 100 watt soldering iron which will heat a carb jet fairly quickly without overheating and use solid core solder with paste flux on the part to be soldered. You can get the 100 watt irons on ebay pretty cheap, and I just picked up a 60 watt iron at HobbyTown last week for $10.
 
Thanks guys great words of wisdom...My problem is the area in which I live. I was hoping to drive to my test site and fiddle with the jets on site. I may need to just pre-drill the two extra jets at home and then try them out. Very hilly where I live and was hoping to test on the flats to see the difference when not under load.
 
You can pre drill a few jets then mark them so you can tell them apart, colored sharpies will work for this in a pinch, but if you can mark them more permanently just so you can tell them apart, even better.
Another thing you can do if you need more jets for tuning is measure the thread size of the jets and use genuine Mikuni, Keihin, Weber, or Dellorto jets that have the same thread size and basic body size and shape of the jets your carb came with.
I did that for my CNS carb since it's a Mikuni clone I got 2 sizes above what it came with and 2 sizes below so I'd have them on hand and ready to swap out on the fly. The advantage of the genuine name brand jets is that they are usually the most accurately sized compared to the chinese knock offs, of course, this doesn't matter if you're going to be drilling them, but it also comes in handy for future projects since you'll already have the jets on hand and ready for tuning.
 
2door said:
Toothy,
You don't need as much heat as a gas torch will provide. I use an electric soldering gun.
You should use solid core solder, not flux core, and I've always had good luck with either 60/40 or 50/50 solder. I like Nokorode paste flux.
The jet MUST be clean and oil free. I like to sand them a little with a 3M pad making sure to get any surface oxidation off leaving clean shiny brass around the orifice.

A pin vice is almost an essential tool for drill bits the size we're talking about. Don't try an electric drill. Run the bit by hand only.

Tom

EDIT: Sorry SuperDave. We were typing at the same time and gave the guy conflicting information. Just another example of "use what works for you" :)
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Ditto....

I use a propane torch myself and clean the jet with spray carb cleaner blow it dry with high pressure air and I cut a very small piece of solid core solder and place it over hole in jet, hold the jet with pliers and then apply heat just until solder melts and fills hole, no more heat is needed and I have done many jets this way without a single issue and unlike some I use no flux, never found it to be needed when soldering jets, its quick and simple, getting the jet hot while having it sit on an electric stove burned should also work just fine if someone doesnt have a soldering gun or torch.

Map
 
Being a fellow redneck I have to agree with the stove top method... just don't let the wife catch ya... lol...
I remember my wife not too happy with me throwing parts in the oven to cure the high heat paint or powder coating... I tried to explain the parts were too big for the toaster oven but I don't think she fully understood...

Seriously, the stove top method will work just fine and the wife should be ok with it too...
 
davezilla said:
being a fellow redneck i have to agree with the stove top method... Just don't let the wife catch ya... Lol...
I remember my wife not too happy with me throwing parts in the oven to cure the high heat paint or powder coating... I tried to explain the parts were too big for the toaster oven but i don't think she fully understood...

Seriously, the stove top method will work just fine and the wife should be ok with it too...
Click to expand...

lol............!
 
Unless you apply too much solder and it runs down onto the heating element or the flame ring. Then you'll have some explaining to do.

Tom
 
2door said:
Unless you apply too much solder and it runs down onto the heating element or the flame ring. Then you'll have some explaining to do.

Tom
Click to expand...

I have a glass top stove so Im not sure how that would work on it but yeah a mess might get a butt chewing going for sure....lol
 
Um... what if we try the microwave? ... it should work and it'll put out a nice light show while you're waiting on it to heat up... :eek:
 
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