Can i use different head nuts on my xr400 - 1998 Honda XR 400R

NGK DPR8Z is the standard plug.

https://www.google.com/search?q=spark+plug+02+XR400

this page is informative.

https://thumpertalk.com/forums/topic/520486-ngk-dpr8ea-spark-plug-for-the-xr400/

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Before you do any work turn you steering to the 'straight ahead position.
This job will depend on if yours is fitted with an airbag. The versions with NO airbag usually have a push fit centre cap you can usually 'Gently' lever out to get access to the mounting nut.
The versions WITH an airbag usually have the centre cover bolted into place.
**If yours has an airbag REMOVE the battery wire BEFORE you start to prevent the airbag going off accidentally.** The heads for these bolts are on the back of the steering wheel and often in deep holes to hide them, so you'll be working blind trying to get them out. Different companies use different styles of bolt so the heads could be a cross head screw, a hex head (Allen key?) or a torx bolt so try one of each.
Once the bolts are out, CAREFULLY lift the airbag out and CAREFULLY disconnect the wire to the airbag. This is the trigger wire which make the airbag detonate. Put it safely to one side, I usually tuck it under the vehicle for safety.
Removing the actual steering wheel is the same for both types. There is a large nut in the centre holding the steering wheel in place. This nut will be tight so you might need a helper to hold the steering wheel still while you use a socket to loosen the nut the first half turn. DO NOT take the nut all the way off, leave it on two or three turns. This stops the wheel hitting you in the face if it comes off suddenly. Rock the wheel as you pull on it. It should come free with a little bit of effort. Remove the nut all the way off. Pay attention to where the airbag wire goes as you lift the old wheel off.
Refitting is the opposite of the above method. First thread the airbag wire into place, Position the wheel so it sits straight. Then fit the nut by hand until finger tight then tighten with a socket. The nut pushes the steering wheel into place so recheck that the nut does not unscrew easily. Refit the airbag wire to the airbag, remount the airbag and reconnect the battery.

Exhaust manifold nuts 10-14Nm
Exhaust mounting bolts 30-14Nm
Engine mounting nuts 45-50Nm
Oil drain bolt 11-15Nm
Oil filter screen cap 10-20 Nm
Spark plug 10 -14Nm
Crank case bolts 8-12Nm
Cylinder head bolts / nuts 18Nm-22Nm
Variator center nut 35-40 Nm 49cc gy6 149cc gy6 40-60NM
Clutch assembly nut for spring 50-60Nm 49cc gy6
Clutch center nut 35-40Nm 49cc gy6 1 49cc gy6 40-60NM
Gear box drain and fill bolt 9-15Nm 49cc -149cc gy6
Fan bolts 9Nm 49cc -149cc gy6
Valve lash adjusting nut 7 Ft Lbs



Standard Torque Setings
M5-Bolt or Nut--5Nm
M6-Bolt or Nut--10Nm
M8Bolt or Nut--21.5Nm
M10Bolt or Nut 35Nm
M12Bolt or Nut 55Mm

M6Bolt or Nut flanged head 12Mn
M8Bolt or Nut flanged head 27Nm
M10Bolt or Nut flanged head 40Nm

There is a special socket set made for stripped nuts and bolts. Sears sells it. There are about five sockets in the kit, each covers a couple different sized stripped nuts/bolts. The socket is spiraled inside and tightens onto the stripped head as you turn it counterclockwise to remove..... DW

No.

The torque specs for your cylinder base nuts are 25ft.-lb.and the head flange nuts at 18ft.-lb.tighten them in criss cross pattern,at three different stages,ex.25ft.-lb.start with 8 then15 then 25,18ft.-lb.start with 5 then 10 then 18.good to go.Hope this helps.

I would try using some Loctite Threadlocker, they offer different strengths, removable and non-removable.

if you can pull the rubber cover off the solenoid you will see two nuts that are the cable terminals, short across these with a screwdriver or similar(may make a spark) if this causes the starter to turn you probably need a solenoid. You could also try a multi meter or test light on the terminal to the starter, it should have power when you press the start button, if not , new solenoid. to change it disconnect the battery , undo the two cable nuts, and follow the other wire back to its connecter

here we go you ready because this is fun the first time. i have included the fishe for this so print it out you'll need it. after removen the fork tubes from the bike you'll remove the nut from the top # 17 it has spring pressuer on it.after you have it off you need to push the spring down and get a wrench on # 18 with the wrench on there twist off #17. remove spring. good luck and for more info hit me back
http://fiche.worldofpowersports.com/wps/Honda_OEM/HondaDB.asp?Type=13&A=161&B=29
Mark
C.C. Motorsports

There is a nut above the head, place a wrench on the nut then unscrew the head from the shaft, unless yours is different from mine this is how it works. I hope this helps.