Makita GN420C, Instruction Manual

11

Nail-driving of concrete

 WARNING:

• Use hardened nails only for concrete.

Using other purposed nails may cause serious injuries. 
Do not nail directly on the concrete. Failure to do so 
may cause concrete fragments to fly off or nails to 
strike back, causing serious injuries.

• When driving nails, hold the tool so that it stands 

upright to the driving surface.
Slanted nail-driving may cause concrete fragments to 
fly off or nails to strike back, causing serious injuries.

• Do not use the tool on the surface that objects hang 

from, such as area where hangers for sewer pipe, dust 
pipe etc. are set up.

Choose and use appropriate nails so that the penetration 
amount into concrete ranges 15 mm - 20 mm.

 (Fig. 21)

 CAUTION:

• Use this tool only for soft concrete built up not so long 

before. Using on the hard concrete may cause nail 
bending or nail-driving to insufficient depth.

• When the penetration amount into concrete is required 

more than 20 mm, driving nails to the sufficient length 
may not be obtained. Nails may be driven too shallow 
causing unstable workpiece, resulting in personal injury 
and damage to property.

Anti dry fire mechanism

This mechanism prevents the tool from firing without nail.
Dry fire prevention automatically functions when the rest 
of nails get to the last 2-3 pieces. 

Jammed nailer

 WARNING:

• Always be sure to remove the fuel cell and the battery 

cartridge before clearing a jam.

 CAUTION:

• Do not use deformed nails or nail strip. Failure to do so 

causes poor nail feeding.

Follow the removing nail procedure and remove the 
jammed nails.

 (Fig. 22)

Remove the fuel cell, the battery cartridge and nails.
Loosen the bolt on the magazine. Remove the magazine 
and remove the jammed nails. 

(Fig. 23)

If the nails cannot be removed after performing above 
method, do as follows.
Insert a small rod or the like into the ejection port and tap 
it with a hammer to drive out the jammed nails from the 
ejection port. 

(Fig. 24 & 25)

If the nails still remain in the ejection port, do as follows.
Loosen the bolts on the ejecting port by using a hex 
wrench. Remove the under driver guide. And remove the 
jammed nails.
Return the under driver guide and tighten the bolts after 
the jammed nails are removed.
Return the magazine and tighten the bolt.

MAINTENANCE

 CAUTION:

• Always remove the fuel cell, the battery cartridge and 

nails before attempting to perform inspection or 
maintenance.

• Never use gasoline, benzine, thinner, alcohol or the 

like. Discoloration, deformation or cracks may result.

Maintenance after daily work

At the end of daily work, conduct an end-of-workday 
routine.
These simple steps are based on maintaining the safety 
and performance of the tool.

Before leaving the work site:

• Remove the battery cartridge and store in a tool-

carrying case. Always use the tool-carrying case for 
transporting and storing the tool.

• Dispose of all empty cells where they will not be found 

by children, crushed, punctured or burned.

When you get home:

• Place the battery cartridge in its charger if it needs 

charging as indicated by the red indication lamp.

• Wipe the tool with a clean, soft cloth.
• Check the filter and clean if it is dusty.

Cleaning the air filter (Fig. 26 & 27)

Press slightly up the filter cover and remove it. And then 
simply lift out the filter.
Tap the filter lightly to remove any dust. Soap and water 
restores the filter to an almost new condition
To maintain product SAFETY and RELIABILITY, repairs, 
any other maintenance or adjustment should be 
performed by Makita Authorized Service Centers, always 
using Makita replacement parts.

Thoroughly cleaning

If dry fires occur frequently, which means the tool is 
needed to be cleansed thoroughly.
See the accompanying cleaning guide for detail, and 
perform the cleaning.
If you have any questions regarding to cleaning, please 
ask your local Makita Service Center.

OPTIONAL ACCESSORIES

CAUTION:

• These accessories or attachments are recommended 

for use with your Makita tool specified in this manual. 
The use of any other accessories or attachments might 
present a risk of injury to persons. Only use accessory 
or attachment for its stated purpose.

If you need any assistance for more details regarding 
these accessories, ask your local Makita Service Center.
• Nails
• Magazine
• Safety goggles
• Fuel cell
• Cleaning kit
• Makita genuine battery and charger

NOTE:

• Some items in the list may be included in the tool 

package as standard accessories. They may differ 
from country to country.