Be careful drilling your jets

[anickode]

I am in the process of tweaking the Intek 190 a bit on el-cheapo. Got greedy, overdrilled the jet, and now it's junk. Makes a **** of a noise above half throttle though

Sounds like the anti-lag on a rally car.

New jet is $19 shipped from Jack's small engines.

New OEM carb is $18 shipped from Amazon, and it'll be here in half the time.

Or I can bust out the flux and solder and go old-school on it to take the jet back down a size.

What a pain in the behind.

 

[Ebrownie]

I bought a micro drill bit set from HF for that purpose, I haven’t used them yet though. I believe one of them is 0.0325” which is smaller than an aftermarket 0.036” for a predator but bigger than stock. Seems like drilling too big would be easy to do.

 

[anickode]

Yep, it's pretty easy to do, especially when the numbers are worn off your drills. Maybe it's time I ordered a new set.

 

[bob58o]

Yep, it's pretty easy to do, especially when the numbers are worn off your drills. Maybe it's time I ordered a new set.

On those little ones, I always have to measure with my calipers to know which one it might be.

 

[65ShelbyClone]

I do that even with marked drills just to make sure they're not tapered from wear.

This is also a PSA that drills typically make a hole that measures marginally larger than the drill itself. I think jets are reamed to achieve the precise diameter, but the price of reamers makes them impractical for casual tinkering.

Fun fact: years ago I made from scratch a bunch of half-increment jets for one of my motorcycles. I even engraved the size on each one under a microscope. Why? because I thought it might actually make a difference in tuning. Did it? Sure....made it take twice as long.

 

[mckutzy]

You could always go to a lawnmower/rental shop and see if they have any carb bits in there junk bin... I'm sure if you ask nicely and if they don't seem busy, they'll let you take a look.. Might even cost you a six-pack or less..

I did the same and got a bunch of jets and a few E-tubes that way..cost me $5.. Cause that's the only bill I had at the time..

 

[TT540]

Fill with JB weld. and redrill!

Keep with the theme.

 

[anickode]

Fill with JB weld. and redrill!

Keep with the theme.

I wouldn't trust JB in there, and it would be a pain to get it through.

50/50 lead solder will flow right through, with proper use of flux. Actually, if you fill it with solder and then blow the solder out before it's cooled, it will tin the bore of the jet, bringing the ID down by a few thousandths. Whether that will be enough is another question. If not, then fill it completely and redrill.