Removing botched up idle jets

Removing a mangled idle jet can be a pain.

To prevent damage to the soft brass jets, only install and remove them with a good quality screw driver that has a square tip in excellent condition.

My technique for removing mangled idle jets is to use an easy out. I like the "Micro-grabit" easy outs made by Alden Company.  They have a drill bit on one side and an easy out on the other side. I mount them in my drill press to keep it straight, and then turn the drill press by hand using the chuck key.

Mount the carb upside down in a drill press vice with soft jaws.

1. When setting the easy out into the hole you drilled in the remnants of the idle jet, release the return spring of the drill press (if your drill press permits) so that the weight of the quill assists you in inserting the easy out into the hole. Do not use the drill press motor.  Turn the drill chuck by hand using the chuck key or thumb wheel.

2. Once the easy out has a bite into the idle jet stub, raise the drill press quill slightly so that there is some upward tension lifting the weight of the carb and vice. Now lock the quill. This will keep some tension on the easy out and make it easier to remove the stub of the idle jet.

3. Once the stub of the idle jet is removed, mount an M4 x 0.7 tap in the drill press and start the tap in a few threads.  Remove the tap from the drill press and finish cleaning the threads by hand.

Honing Bing Carburetor slides

Sticking carburetor slides are often a problem on /2's.  Before you go about attempting to hone your carb slides and bores, check your cables, cable routing, and throttle grip mechanism. Often times a sticky carb can be linked to a bad cable that otherwise looks fine or cable routing that pinches the cable.

If you cables look old, replace them.  If you have teflon lined cables, do not lube them.

Typical Situation of Pinched Throttle cables

A good rule of thumb for pinched cables is to check to see if the problem is worse when the bars are turned to the left or right. If moving the bars seems to affect the problem, it is probably a pinched cable.

Another area to check is the twist grip mechanism itself.  Check out this other article about that.

Ok, now let's have a look at those carbs.

I use a sharpie to mark up the slide like this:























So when I slide it inside the bore, I can see where it is rubbing.  Then I can take a piece of 1000 grit sand paper and take down that area a bit.























Sometimes you find that the slide is tight in the bore all the way around. This is often the case when replacing parts or when fitting a carburetor together from parts.

Before going this route, be absolutely certain your slide is good. Check to be sure it is a true cylinder by measuring at different points up and down the cylinder using a micrometer or caliper. All measurements should be equal.

If your slide is worn, replace it.

Once you are certain your slide is good, then you can bore the carburetor body to fit the slide.

Using a brake cylinder hone, hone the carburetor body. Use plenty of WD40 as a lubricant so that particles will not scratch the new surface. Measure at frequent intervals by cleaning the debris out of the bore and inserting your slide. Ensure that the new slide is as tight as possible while still allowing easy movement in the bore.