Sparks ignition key vs XR 400 ignition key

[Braff1]

I have been looking at putting in a Sparks ignition advance key on my 400 EX. But while researching about it I began to wonder if the Sparks key (15.00$) which returns the 400 EX back the XR 400 timing is the same key used in the xr 400 engine (3.23$).

I'm not sure, but wouldn't the sparks key have a slight offset in it to move the ignition rotor on the crank end? The difference is where Honda machines the keyseat in the crank, not the key itself.Please tell me if this is the real deal or if I'm off base.Thanx.

I think your right! Always assumed that the flywheel was notched different but could just as well be the crank slot. Dollors to donuts that the EX and XR woodruff keys are identical, probably even same part #. :)

[shook]

How does that 400ex of yours run Im looking at doing the same mods you have used on your quad will it fly.

Shook

I doubt that it's as fast as the big bore motors here but it's a whole lot faster than stock!
If I did it over again I probably would get a slip on silencer instead of a complete system because I run the quiet core and spark arrester so I don't think I get much benefit from a complete system.
I just installed the ignition advance key and noticed that the engine has even better throttle response and pulls harder from the bottom end.
After my mods I found that the machine is easier to ride quickly and the power band feels about the same, but--- way more power from bottom to top. Reliability and maintenance seem about the same, engine doesn't run hot, I can use pump gas, etc.
About the only drawbacks are that the exhaust is louder than stock and the exhaust pipe feels hotter without the heatshield by your leg. I've got a modded airbox lid and haven't had any water or dust problems--- yet. Hope this helps! :D :D :D

[max400EX]

Who has had problems with TDC and their timing keys? I hear it messes up the way you adjsut your valves and stuff (the key does)

Yes, the advancement key will cause your indicator mark on the flywheel to be off in locating TDC. You will need to use an indicator through the spark plug hole.

[sduncan]

Does anyone know for sure if these two keys are the same or not? I'm tempted to try the XR key to see if there is a difference . Any particular year to ask for at the dealer?

[max400EX]

Thanks dirtyp,
So I can still adjust the valves to the stok configuration and it will be fine right?

[MIKE400EX]

Flywheel keys are identical. The crankshaft assemblies and flywheels are different. The timing difference is probably (only) in the ignition box, that would be the least expensive way for Honda to do it - production wise. Does someone out there have access to an XR400 & 400EX? Put them both at TDC and compare the pickup location.