Impact Driver Tool | Vintage Honda Motorcycles
The screws that hold the engine side covers on a vintage Honda are often stuck so hard that a regular screwdriver won’t move them, and every failed attempt chews up the head a little more. An impact driver is how we get them out. You seat the bit in the screw, hit the back of the driver with a hammer, and it breaks the screw loose without stripping the head.
Why You Need This
The engine side covers on the Honda CT90, CB100, CB125, CB175, CB200, CB350, CB360, CB450, CB550 and CB750 are held on with cross-head screws that look like Phillips but are JIS (Japanese Industrial Standard). The shape is ever so slightly different from an American-standard Phillips, so a Phillips screwdriver strips the heads more easily. Trying to remove them with a regular screwdriver is a futile effort if not impossible.
Once a head strips, you’re drilling it and using a screw extractor to get it out. The impact driver makes quick work of the job before it gets that far. Once the screws are out, we replace them with our stainless steel Allen bolt kits so a stuck side-cover screw is never a problem again.
It isn’t only for side covers. It’s what we recommend for stubborn points cover screws too, and it’s very handy for breaking stubborn screws loose on any mechanical device. It’s a toolbox must for working on vintage motorcycles.
Specifications
| Spec | Detail |
|---|
| Type | Hand impact driver, struck with a hammer (not an air or electric impact wrench) |
| Head | 3/8" quick release |
| Included Tips | Four: two Phillips and two flat head |
| Optional Add-On | Long-reach JIS impact bits in Size #1, #2 and #3 |
| Fits Models | CT90 / Trail 90; CB100 / CL100 / SL100; CB125 / CL125 / SL125; CB175 / CL175 / SL175; CB200 / CL200; CB350 / CL350 / SL350; CB360 / CL360 / CJ360; CB450 / CL450 / CB500T; CB350F / CB400F; CB500K / CB550K / CB550F; CB750K / CB750F / CB750A |
| Warranty | 90 days from the date of purchase |
| Sold As | Sold Individually |
It’s a universal tool, not a model-specific one. The models above are the vintage Hondas we list it for, but it will break loose a Phillips, JIS or flat-head screw on anything its tips fit.
What’s Included
- Impact driver
- Four tips: two Phillips and two flat head
- Metal storage box
Optional JIS bits: the four standard tips are not JIS. For a matched fit on JIS screws, add the long-reach JIS impact bits with the Size #1, #2 and #3 checkboxes on this page. The #2 and #3 are the sizes you’re most likely to need. The #1 tip is narrower and isn’t a common size.
How to Use It
Difficulty: Beginner (it takes a little practice)
Tools needed: A hammer. We use a 2 lb brass hammer.
- Fit the tip that matches the screw. The correct size matters.
- Seat the tip in the screw head and hold the driver square to the screw.
- Push in hard and twist the driver the way the screw needs to turn to come out, with a firm grip. That pressure keeps the tip from slipping out of the head and stripping it.
- Give it a firm seating tap first, then strike the back of the driver with a solid blow.
- When you hear a good “crack” and the screw head moves, you hit it hard enough.
Don’t hold back. First-time users tend not to hit it hard enough. The larger the hammer, the more force you can put into the driver. We like a brass hammer because it bounces less than a steel one.
Tight spots: to reach a recessed screw, fit a 3/8" extension between the bit holder and the driver. If the bit holder still gets in the way, as it can around the right engine cover, longer bits solve that. The long-reach JIS bits on this page are made for this driver.
The start of this CB450 engine removal video shows the technique on the side cover screws: push in, twist toward loosening, and give it a good crack with a brass hammer. The driver on camera may look different from the one we ship now, but the technique is the same.
Frequently Asked Questions
Is this the same as an impact wrench?
No. An impact wrench is an air or electric tool. This is a hand impact driver, sometimes called an impact screwdriver. You put a bit in it, set it in the screw, and hit the back with a hammer to break stubborn fasteners loose.
Will it work on my bike?
Yes. It’s a universal tool, not model-specific. It breaks loose any Phillips, JIS or flat-head screw its tips fit, on the CT90 through the CB750 and on other bikes of the era.
Are the included tips JIS?
No. The four standard tips are Phillips and flat head. We regularly use the impact driver with its standard tips to break loose the stock JIS side-cover screws before swapping them for Allen bolts. If you want a tip that matches the JIS screw head, add the optional JIS bits. You’ll most likely need the #2 and #3.
Should I use this or JIS screwdrivers?
Both have a job. A JIS screwdriver fits the screw properly, but if a screw is truly stuck, even a JIS screwdriver won’t get it out. The impact driver is our go-to for extremely stuck screws that aren’t yet stripped. If you’re working on a lot of JIS screws you won’t need to impact, the JIS Screwdriver Set (3-Piece) is handy to have too.
What if the screw head strips anyway?
Work up the list from easiest to hardest. First the impact driver. Next, grab the head with vise grips if you can reach it (often you can’t on these engines). Then drill the head just enough to use a screw extractor; reverse-spiral extractors tend to work best. As a last resort, drill the heads off, slide the cover off, and grab the leftover studs with vise grips. Some screws, like the tachometer drive screw on the CB360, can still break and need drilling out even with an impact driver.
Should I put the old screws back in?
We don’t. We replace them with our stainless steel Allen bolt kits and put anti-seize on the threads, so the covers come off easily next time. See the kits for your model below.
You Might Also Need
- JIS Screwdriver Set (3-Piece) — #1, #2 and #3 JIS screwdrivers for the cross-head screws you turn by hand
- Impact Driver Bit Set — four replacement tips (two Phillips, two flat head) for this driver
- Anti-Seize Lubricant — for the threads of the new Allen bolts
- Stainless steel Allen bolt kits to replace the side-cover screws:
- Allen-head ignition points screw sets:
Last updated: September 2026
