Rev limiter ???

4 replies to this topic
  • skippy

Posted April 19, 2002 - 01:02 PM


I've got a wr400-99 Australian ,Canadian bike. No grey wire.
Can anybody tell me at what revs does the rev limiter cut in & how do you test it.? What to use & where to connect it.

  • SFO

Posted April 19, 2002 - 01:32 PM


When I tested my us wr on the dyno the limiter kicked in at 10.5k.
The yz stock is 11.5k.
I wouldn't no load test it...I would do it on a dyno with an inductive tach.

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • Taffy

Posted April 19, 2002 - 01:51 PM



i've been here two years and i'd heard the rumour without facts but that does sound pretty emphatic.


  • Mark_Cantrell

Posted April 19, 2002 - 11:41 PM


I'm not saying this applies to a 99 400. On the newer bikes, the rev limiter is higher but is affected by the sky blue wire which detects neutral gear. In neutral the rev limiter is reduced (according to popular theory).

If you test it, I would recommend an inductive tach. An inductive tach may be tricky. The stator is on the crankshaft and pulses every revolution. A four stroke has a power stroke, and therefore needs a spark, every other revolution. I believe, but don't know, that this bike which gets a stator pulse every revolution, actually fires the plug every revolution, even though it is wasted on an empty cylinder every other time. This means a tach for a car would show twice the RPMs that are actually turned while a tach for a two stroke bike would show the correct RPM.

On the other hand, if the CDI only fires when needed (how would it know unless the stator was on the camshaft where any good 4 stroke motor's stator should be, 1/2 the RPM of the crankshaft) a car tach would measure correctly and a tach for a two stroke would show 1/2 of the true RPMs.

Finally, if you test it on a stand (not a dyno), it would show the neutral rev limiter (unless you're brave enough to hold the clutch on a screaming beast in gear or have the wheel spin just above the ground). On a dyno or on the road, it would show the non-neutral rev limiter which is more of interest. Again, I don't know if the 99 has a neutral detect circuit.

I meant to be helpful but now I may have confused the issue. Sceptor is an EE, maybe he could run a quick and dirty test. Also, on the 250F forum under the subject "CDI 101" is an introduction to the CDI.


  • SFO

Posted April 20, 2002 - 07:10 AM


The dynojet dyno has its own tach that you can manipulate for # of sparks.
You can't really get a reading without knowing your rpm.
Actually I tested the stock wr ignition without the grey wire, and a vortex.
The party was over before 10.5k anyways, no point in spinning it harder.
The ignition does spark every rev btw.


Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.