Brass Jet Vs Aluminum Tool?

[great white]

I have to make a tool to change jets in my bike's carburetors.

The "head" is a 6 mm round slotted deal. Like so:


You can't use a normal screwdriver on them as the slot has square edges and a regular common tends ot slip and mar them up.

Normally, I'd just use a tool like this:



It centers the jets and applies the force in the proper place. But my bike has downdraft carbs with small side mounted float bowls. This means the plug over the jet area is very small. Just large enough to extract the jet, no room to fit a tool like above in there.

The other option is removing the carbs and bowls to change the jets. As you have to drop the engine to get the carbs out of my bike, that's obviously not an attractive option.

So I'm looking to machine a tool that will fit the slot in the jet and fit in through the bowl plug hole. BAsically a square sided screwdriver bit arrangement.

My question is: is aluminum a suitable material to make this tool for a brass jet out of?

I don't want it to be too soft, but I'm not keen on using steel either. It doesn't have to stand up to a lot of use, just a couple rounds of jet removal/installation with I get the mixture right. Very little torque/force on a jet also.

Aluminum is also attractive to me as it's easy for me to machine with my limited capabilities (milling attachment on the lathe).

Thoughts?

 

[Tony Wells]

I would think the aluminum to be too soft unless you happen to have some 7075. And in the right condition.

Have you looked at gunsmith screwdrivers? They have parallel sides and don't try to cam out as much as the common slot driver.

 

[kd4gij]

I have a set of bits for that. They are steel. I have also taken the small screw driver from the HF give away set and ground it for that purpose .

 

[great white]

I would think the aluminum to be too soft unless you happen to have some 7075. And in the right condition.

Have you looked at gunsmith screwdrivers? They have parallel sides and don't try to cam out as much as the common slot driver.

I'll have to have a look at that option.

Thanks.

 

[John_Dennis]

I would not use a soft HF screwdriver on an important part. If you damage the jet you will suffer a lot.

 

[roadie33]

I use a set of Gunsmith screwdrivers as they are for the square screws used on firearms to be able to tighten them better. I have this set. Different sizes for the different screws on a firearm.

 

[RJSakowski]

I have to make a tool to change jets in my bike's carburetors.

The "head" is a 6 mm round slotted deal. Like so:


You can't use a normal screwdriver on them as the slot has square edges and a regular common tends ot slip and mar them up.

Normally, I'd just use a tool like this:



It centers the jets and applies the force in the proper place. But my bike has downdraft carbs with small side mounted float bowls. This means the plug over the jet area is very small. Just large enough to extract the jet, no room to fit a tool like above in there.

The other option is removing the carbs and bowls to change the jets. As you have to drop the engine to get the carbs out of my bike, that's obviously not an attractive option.

So I'm looking to machine a tool that will fit the slot in the jet and fit in through the bowl plug hole. BAsically a square sided screwdriver bit arrangement.

My question is: is aluminum a suitable material to make this tool for a brass jet out of?

I don't want it to be too soft, but I'm not keen on using steel either. It doesn't have to stand up to a lot of use, just a couple rounds of jet removal/installation with I get the mixture right. Very little torque/force on a jet also.

Aluminum is also attractive to me as it's easy for me to machine with my limited capabilities (milling attachment on the lathe).

Thoughts?

I made a tool for a similar purpose. The tool was made by milling the blade on the end of a shaft and gluing a sleeve to prevent slipping off the adapter. Similar in concept to you pictured tool but it could fit inside a 1/4-36 threaded piece.

 

[ARKnack]

I think I'm going to disagree here. I would think aluminum would work. First, your driver blade is short and thick so it will have a decent resistant to shearing. Second, brass is a soft materiel like aluminum so you are not torquing the jets very hard. Third, this is a specialized tool made for a specific job so it will not be used more than a few times. So ware isn't a factor.

I suggest you make one and try it out on a scrap carburetor. If it works, epoxy a old screwdriver handle on it. If starts to ware out just make o new one.

 

[Ebel440]

I think aluminum would work at least if the jets are not corroded in and stuck. I like the idea above about epoxing a thin wall tube over it. I would just regrind a round screwdriver to a better angle then slip thin tube over and epoxy or solder it. Fast and easy. I actually have some webers I need to rebuild and that's what I'm going to use for it

 

[British Steel]

I think aluminum would work at least if the jets are not corroded in and stuck.

That's a big "IF", dissimilar metals threaded together in the presence of newfangled hygroscopic "gasohol"... [1]

I'd definitely use steel, and a decent grade too! Piece of rod (could be any old mild steel), piece of gauge plate loctited in a slot after hardening and tempering, make the plate a *tight* fit in the slot, the rod a close fit in the thread into the carb (or the hole (bowl plug hole?) you have for access if the jets stands proud).

If there's clearance enough, a piece of suitable tube (if necessary with a bit of boring out) that locates on the carb body and guides the driver to keep it square and central would be a good compromise... Carb' bodies, especially Webers and Keihin etc., aren't cheap!

Dave H. (the other one)

[1] The "super unleaded" allegedly has no ethanol in it, so kinder to carb' O-rings, less risk of internal corrosion.