So I read that you can just drill out the jet to change sizes. Why doesn't somebody just figure out what size bit makes each size of jet then stick it in the WIKI? Why would you buy a jet when you can just drill it out?
So I read that you can just drill out the jet to change sizes. Why doesn't somebody just figure out what size bit makes each size of jet then stick it in the WIKI? Why would you buy a jet when you can just drill it out?
lowes doesnt carry .05 mm drill bits.
One problem is that jets don't all have the same numbering system. Make sure you file off the old numbers when you drill them out.
i personally think drilling jets is kinda foolish. you can mess it up, break your bit, crack your jet, and its harder to guage how much fuel its sucking up in reference to other jets. If you plan on owning a moped for a while, especially if you are going to modify/performance tune it, just buy a handful of jets. it's worth it in the long run.
Well I found a chart that somebody did like this and posted it up in the wiki.
they sell a set of 61-80 size drill bits on ebay. they range in size from .3-1.1 mm(off the top of my head, may not be exact) or jet sizes 30 to 110. here's some linkage: http://cgi.ebay.com/Tiny-Small-20-bit-61-80-DRILL-BITS-HSS-FREE-PIN-VISE_W0QQitemZ260165474729QQihZ016QQcategoryZ486QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
There are many other like it on ebay, search "drill 61 80" and you'll come up with a bunch. don't use them with your dremel though. it's really easy to drill them out with that pin vise or even a pair of pliers holding the bit
Dr. Jet says; This is stupid, Caused by insane prices from terrible moped webstores. Bing jet hole's have corresponding conical funnel like shapes that let petroleum flow to the hole efficiently and correctly, impossible to duplicate at home, and an ever important design element in jet functionality. therefor buy $3 jets off ebay!
dr. experience says i do it all the time, i dont buy jets if i dont have to, and my bikes are fast as fuck.
they are actualy jet reamers not drills. and yes they work just fine like harold said. I havent bought a jet (besides a bunch #48s to ream out) in forever.
reamer kit
http://www.cbperformance.com/catalog.asp?ProductID=525
plug gauges (.45mm to 1.50mm is moped range)
Thanks Vic adding those pieces to the wiki I made now
In hydraulic physics the restriction to flow is dictated by the smallest orifice in the system. A tapered hole would flow the same. With air it is different because air compresses but fluids don't except at other than this worlds pressures. I am going for the number drills.
There's a way cheaper alternative to that and it's the same thing it seems. If you have a harbor freight or just go on their website, they sell MIG welding tip cleaners which act as teeny tiny files (I'm sure in the same way). I plan to use as necessary as the temperature drops here in GA for the winter and I change jetting to then go real real fast on crisp cool air.
If no Harbor freight this ones a cheapie:
http://www.welders-direct.com/merchant2/merchant.mv?Screen=PROD&Store_Code=WD&Product_Code=STC-KTC
still a waste of time, economics says: today's supply and demand of original jets will retain their value, so just buy and sell what you don't need.
Drill them out ? HUH thats what top fuelers have been doing since the early 70's .Why buy a bunch of pre-drilled jets when the drilled one will do the same thing?Also have you ever bought spares in different numbers and the when you go looking for say the size 77 jet you cant find it? What do you do when you need it now and aint got time to dick around looking for another one, going to the shop, and coming back?You drill the shit out of it!
those tip cleaners probably wont work too well. they arent designed to cut, just break off carbon deposits. plus they arent indexed in any way.
a jet reamer is like a 4 sided tapered needle. as you turn it and press in the brass gets cut and pushed to the side. this is also how you control the size of the reaming. the further down the needle you go the bigger you get. you can even concievably do half sizes or even quarter sizes.
those jet reamers are the best way to go, i've used them once. I just posted the micro drill bits as a cheap alternative.
As I understand there are many micro drill side numbers between each jet size so you can go between jet sizes
Only a few number drills match up to normal jet sizes. Plus, these are very small, delicate drills... you better know what your doing.
It's not hard to drill out jets. For the price of shipping and two jets (which you will probably need more than two) you can buy a set of microdrills from a hobby shop and drill out any jet to any size. That's what I did and my bike runs perfectly. If a jet is too large you can fill the hole with solder and redrill the jet.
Good Luck,
Eric
DRILLING AT HOME IS MORE ACCURATE THAN STORE BOUGHT JETS YEAH RIGHT YOU DRILLERS SHOULD BUILD RACE ENGINES IN YOUR SPARE TIME!!!!!
The links Vic put up for the reamers and plugs are sold out of them. Anyone know anywhere else to order them from?
those reamers and gauges look pretty handy, and i'm all for new gadgets and doing things oneself, but for the cost of those tools, you could go to the local motorcycle shop and buy about 24 jets.
i pay ten bucks for a set of ten micro drills from drillbitcity.com, they are awesome, i have the corrolating jet sizes right above them written on the case. works like a charm, its absurd to pay 5 bucks a jet when you can just 'fix it' in a second. I keep a full set of jets, just to dial it in, cause i dont always guess right the first time, and i jet rich for breakin, but once i find the right size i drill the jet. works great, super cheap and easy. never soldered one back up before.. not sure how well that works, usually i only have to go bigger, if i go too big i keep it for something even bigger and use a different small jet.
24 jets for a bing/dellorto carb would run you like 150 bucks, the reamer and gauge set is that expensive?
jets for the mikuni carb on my qt50 cost me $2.50 each at the local motorcycle shop. i think i read somewhere that the bing/dellorto jets are interchangeable with mikuni jets. i don't know if the numbers match up though.
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