Rev limiter?

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KiwiBiker
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Rev limiter?

Post by KiwiBiker » Sun Nov 27, 2016 5:33 pm

Do the GK76s have an eletronic rev limiter to stop you destroying the motor? Have been finding it hard at times to hear my own engine at times when racing due to the noise of other bikes around me.

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4hundread
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Re: Rev limiter?

Post by 4hundread » Mon Nov 28, 2016 4:29 pm

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Last edited by 4hundread on Sat Feb 18, 2017 11:34 pm, edited 1 time in total.

SevenThreeSeven
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Re: Rev limiter?

Post by SevenThreeSeven » Tue Nov 29, 2016 5:56 am

Do you have a copy of the Service Manual for your GK76?

I ask because in the Electrical System chapter of the GSF400 Service Manual (chapter 6, page number 5) there's a description of the Ignition System that includes the following:

Image

Maybe Suzuki put information about the GSXR400's rev limit in the same place.

(side note: that added "CAUTION" statement is interesting to me because it shows just how basic/rudimentary/old-school the Ignition Controls are on these '90s bikes. On modern bikes you can't accidentally overshoot the rev limiters because they have the capability to invoke both "soft" and "hard" limits to fine tune the cutout. But on our older bikes the ignition cutoff circuit only works well when you approach the RPM limit at a reasonable rate.)

KiwiBiker
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Re: Rev limiter?

Post by KiwiBiker » Tue Nov 29, 2016 7:34 am

SevenThreeSeven wrote:Do you have a copy of the Service Manual for your GK76?

I ask because in the Electrical System chapter of the GSF400 Service Manual (chapter 6, page number 5) there's a description of the Ignition System that includes the following:

Image

Maybe Suzuki put information about the GSXR400's rev limit in the same place.

(side note: that added "CAUTION" statement is interesting to me because it shows just how basic/rudimentary/old-school the Ignition Controls are on these '90s bikes. On modern bikes you can't accidentally overshoot the rev limiters because they have the capability to invoke both "soft" and "hard" limits to fine tune the cutout. But on our older bikes the ignition cutoff circuit only works well when you approach the RPM limit at a reasonable rate.)
I dont have a service manual but cheers for the info. A couple of times on the weekend when racing hard I felt the power drop off and looked down to see the tacho needle on 15K but I wasnt sure if the drop in power was due to the valves bouncing or a rev limiter. Either way it was definitely under load at the time so not expecting any damage. Was just curious really.

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Re: Rev limiter?

Post by moforockband » Sun Dec 04, 2016 8:41 pm

You may destroy your motor running it that high. You will get valve 'float' eventually, and then the pistons hit the valves, causing usually catastrophic damage. I've done it :(
The motor loses power after 12.5 K, so change up at 13 if you wanna keep it in one bit, and make more progress
The limiter will cut in at 13500 electrically, but if you downchange too fast, you will mechanically overspeed the motor and kill it.

KiwiBiker
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Re: Rev limiter?

Post by KiwiBiker » Tue Dec 06, 2016 11:36 pm

moforockband wrote:You may destroy your motor running it that high. You will get valve 'float' eventually, and then the pistons hit the valves, causing usually catastrophic damage. I've done it :(
The motor loses power after 12.5 K, so change up at 13 if you wanna keep it in one bit, and make more progress
The limiter will cut in at 13500 electrically, but if you downchange too fast, you will mechanically overspeed the motor and kill it.
Thanks, yes I was using 13K as my change up point when racing. I found to be competitive I had to be between 10K & 13K in the meat of the power band. Ultimately tho it still wasnt quick enough so I purchased an '07 SV650 last week.
The Gixxer is now (reluctantly) for sale but it's been an enjoyable ride that got me into racing and put lots of smiles on my dial. And it was reliable.

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Re: Rev limiter?

Post by moforockband » Wed Dec 07, 2016 10:08 pm

I raced minitwins and F400 (for 20 years on and off lol). I loved the 400's, but found the sv's a little boring.
They didn't steer as fast or sound as mental. And the brakes are shit! Kept boiling mine.
You are right tho, the gsxr needs another 10 hp to be competitive, especially against modern 400 power. It's a shame it's so hard to tune and keep at 399cc, because it's a great bike.
I'm gonna keep my 400 forever, I love it! I'd miss the ear deafening racket(and upsetting modern sportbikes at cadwell park on track days)!
Good luck with the SV, and watch out for them twin piston brakes!!

KiwiBiker
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Re: Rev limiter?

Post by KiwiBiker » Sun Dec 11, 2016 10:52 am

moforockband wrote:I raced minitwins and F400 (for 20 years on and off lol). I loved the 400's, but found the sv's a little boring.
They didn't steer as fast or sound as mental. And the brakes are shit! Kept boiling mine.
You are right tho, the gsxr needs another 10 hp to be competitive, especially against modern 400 power. It's a shame it's so hard to tune and keep at 399cc, because it's a great bike.
I'm gonna keep my 400 forever, I love it! I'd miss the ear deafening racket(and upsetting modern sportbikes at cadwell park on track days)!
Good luck with the SV, and watch out for them twin piston brakes!!
The brakes are better than the ones on my GSXR. It has braided lines and sintered pads so don't know if that's the difference but was pretty impressed with them.


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