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3TJ Rev limiter

Posted: Mon Apr 20, 2009 10:40 am
by magsmagsmags
what should the limiter come in at when riding? in neutral it seems to redline at around 15,500 but in gear it seems to hit the limiter a lot sooner

Re: 3TJ Rev limiter

Posted: Mon Apr 20, 2009 11:22 am
by Evilchicken0
Tell me your revving your bike to 15.5 thou rpm in neutral.

Riding flat out yes it's 15.5 I've run into it on a trackday.

If you have a M-Max box the bike will rev out depending on the tail wind and length of the downhill straight but the peak power is at 13.5 for a healthy fresh engine.

Re: 3TJ Rev limiter

Posted: Mon Apr 20, 2009 11:25 am
by magsmagsmags
mine seems to cut in closer to 13,000 when in gear, does this mean its still jap restricted?

Re: 3TJ Rev limiter

Posted: Mon Apr 20, 2009 12:09 pm
by Evilchicken0
The restriction comes in in two ways:

Generally in top at 180 ... but nearly 190 kmh it will cut the spark on one and then two cylinders. It's at 112mph ish - so not really a problem
Then if the CDI doesn't recieve a signal from the speedo at 0 it will restrict to 12,500 in all gears.

The M-Max or other boxes like it removes the restrictor or a KMH/MPH converter moves the restriction to 180mph so it doesn't become an issue.

Re: 3TJ Rev limiter

Posted: Mon Apr 20, 2009 12:18 pm
by plodder
Mine was doing that when one of the coils was breaking down. It got to about 12K and then struggled up from there.

Replacement coils fixed it.

Re: 3TJ Rev limiter

Posted: Mon Apr 20, 2009 12:32 pm
by magsmagsmags
Evilchicken0 wrote:The restriction comes in in two ways:

Generally in top at 180 ... but nearly 190 kmh it will cut the spark on one and then two cylinders. It's at 112mph ish - so not really a problem
Then if the CDI doesn't recieve a signal from the speedo at 0 it will restrict to 12,500 in all gears.

The M-Max or other boxes like it removes the restrictor or a KMH/MPH converter moves the restriction to 180mph so it doesn't become an issue.
12,500 sounds about right, so your saying a derestriction box would sort this?

the kmh to mph converter, does that just remove thr 112mph restriction or would that stop the 12,500rpm restriction too?

Re: 3TJ Rev limiter

Posted: Mon Apr 20, 2009 12:54 pm
by Taggyd
with the speed converter you dont go fast enough for it to be an issue so it will never cut in the rev limiter, on the road its easier to just stick a converter in then you can use the kph clocks as mph job done!
have use of an mmax for the race bike cos i dont want to know how fast im going :scare:
specially into edwins at mallory where i binned it on wednesday! oops!
but it means no speedo cable and no rev limit to intrude as you will hit over 112 mph on the straight!

Re: 3TJ Rev limiter

Posted: Mon Apr 20, 2009 1:14 pm
by Evilchicken0
If your speedo has been butcherred then the CDI restricts to 12.500 so you'd need a M_Max box or another speedo to send the 0kmh signal to the CDI.

If however theres a different problem then the box won't alter it.
Take the top fairing off and have a looking the back of the speedo. There should be some wires (a 3 wire block and a single) that go ing to the speedo check they're ok and connected before you move onto something else.

Re: 3TJ Rev limiter

Posted: Mon Apr 20, 2009 7:02 pm
by magsmagsmags
checked today, when riding it definitely redlines at about 12,500 to 13,000 in any gear. I will try and have a look at the speedo tomorrow.

If i do get the M-Max box, will i still have a working speedo? or will i lose it all together

Secondly, if i got the speedo converter would this sort the rev limiting issue? or would it only affect the 112mph restriction

Re: 3TJ Rev limiter

Posted: Mon Apr 20, 2009 10:08 pm
by Evilchicken0
If - it's just the speed restriction that's cusing it then the a derestriction box will work if all it does is plug into the loom.

You have to look at the back of the speedo before you can decide what is causing the problem