not rev'ing past7500

Twangled your powervalve grommit in your woodruff key? ask someone how to fix it here
Mouser
Heavy Smoker
Posts: 118
Joined: Tue Nov 05, 2013 9:57 pm
Location: Luxemburg

not rev'ing past7500

Post by Mouser » Sat May 26, 2018 4:06 pm

Hi people,

I suddendly now have that strange problem that my Kr1 won't rev past 7500. At 7500 it just "stops", just as you would keep the gas as to keep 7500, it does not do any strange noise or anything like that...it just won't go further.... always exactly at 7500. If i switch to a lower gear then, I do get to ~9000. Then it rev's but with a very deep sound and has no power at all and slowly falls to 7500 where it then stays..

I did switch the CDI. Nothing changed. What could this probyble be???

Until 7500 it behaves absolutely normally, sound, power etc.

Has anyone had that before?

Thanks
Mouser

User avatar
Binetta Steve
Oil Injector
Posts: 820
Joined: Sat Nov 10, 2012 6:13 pm
Location: Lancashire

Re: not rev'ing past7500

Post by Binetta Steve » Sat May 26, 2018 5:29 pm

Do your kips vaves cycle when the ignition is switched on. Then do they open as the revs rise towards 7000rpm

Steve

User avatar
JanBros
Premix Junkie
Posts: 2986
Joined: Wed Jul 26, 2006 11:50 pm
Location: the land of Francorchamps
Contact:

Re: not rev'ing past7500

Post by JanBros » Sat May 26, 2018 11:50 pm

you seem to atract electric gremlins, Mouser.

I would put a strobe on it ang go riding, you'll immediatly see if your ignition cut's out or not.
You know it's cold outside when you trip over dog shit instead of standing in it.

Mouser
Heavy Smoker
Posts: 118
Joined: Tue Nov 05, 2013 9:57 pm
Location: Luxemburg

Re: not rev'ing past7500

Post by Mouser » Sun May 27, 2018 6:20 pm

The valves do their normal check when i switch on. They are in the correct position.

I should check if they switch at 7000 rpm...good idea.
So they do turn completely at 7000 or do they turn progressively from 7000 on?

@JanBros

I don't see what you want to say with putting a strobe on it and then trying a run?? You mean charging the battery? If yes why would a battery that does not charge correctly (and so the voltage being too low give that problem and always precisely at 7500 with apparently no problems below 7500?

Thanks for you replys
Mouser

Gerrit
Heavy Smoker
Posts: 247
Joined: Fri Jun 26, 2009 12:09 am
Location: Kingdom of the Netherlands

Re: not rev'ing past7500

Post by Gerrit » Sun May 27, 2018 9:33 pm

The KIPS valves are either in fully open (above 7,000 rpm) or fully closed position (below 7,000 rpm); unlike Yamaha's Power Valve they do not open gradually.
"Mine is a long and sad tale", said the mouse.
"Indeed it is", said Alice, looking at the mouse's tail.

User avatar
JanBros
Premix Junkie
Posts: 2986
Joined: Wed Jul 26, 2006 11:50 pm
Location: the land of Francorchamps
Contact:

Re: not rev'ing past7500

Post by JanBros » Sun May 27, 2018 11:57 pm

a strobe is used to check the timing of the ignition. if the strobe flashes, the plug emits a spark, so if you strap the strobe on the bike and it still flashes at 7.500 rpm, you know at least that your ignition is still working.

KIPS not opening can never be a reason why the engine wouldn't rev past 7.500, that's way to early.
You know it's cold outside when you trip over dog shit instead of standing in it.

Gerrit
Heavy Smoker
Posts: 247
Joined: Fri Jun 26, 2009 12:09 am
Location: Kingdom of the Netherlands

Re: not rev'ing past7500

Post by Gerrit » Tue May 29, 2018 7:35 pm

If you have a spare ignition coil try that. It's possible that the coil may be breaking down at higher RPMs; remember that these bikes are now well over 25 years old as are their ignitions.
"Mine is a long and sad tale", said the mouse.
"Indeed it is", said Alice, looking at the mouse's tail.

Mouser
Heavy Smoker
Posts: 118
Joined: Tue Nov 05, 2013 9:57 pm
Location: Luxemburg

Re: not rev'ing past7500

Post by Mouser » Tue May 29, 2018 8:08 pm

I'll see if the kips switch at 7000rpm. If yes, I'll try another coil. I have a spare one.

Thanks
Mouser

Mouser
Heavy Smoker
Posts: 118
Joined: Tue Nov 05, 2013 9:57 pm
Location: Luxemburg

Re: not rev'ing past7500

Post by Mouser » Wed May 30, 2018 11:43 am

Hi guys,

I did change the coil. The KIPS valves won't open at 7000rpm. I tried driving and in neutral. It just "blocks"reving at ~7500rpm. Like a rev limiter....

I did change the CDI, the problem persists.
I had that problem with the bike not sarting anymore in 2017. I found 6V coming from the RPM tacho in winter...I cannot find the topic back....searched the whole forum....anyone knows where it did go ?!?

Anyway, I did change the RPM tachometer in winter then (6V on the cable going to the coil where gone then) and found out that the cable coming from the pick-up coil was broken.

I did change the pickup coil then with one from an zzr600 1991 from ebay. I could not find a KR1 one so I took that, I was similar....this one seems to work too, as the engine revs normally to 7000rpm....
I really don't get it. The valves do their test when switching on, but don't open at 7000rpm....

Has anyone an idea here please ??? I'm really stuck....what "elemt" has an influence on the valves opening at 7000rpm wich does not influence the test when switching on?

Thanks
Mouser

@Admin: Maybe this whole topic could be moved to the electrical subfolder as it seems to be an electrical problem. Thanks.

Gerrit
Heavy Smoker
Posts: 247
Joined: Fri Jun 26, 2009 12:09 am
Location: Kingdom of the Netherlands

Re: not rev'ing past7500

Post by Gerrit » Wed May 30, 2018 6:30 pm

The valves cycling open and shut indicates the servomotor responds to a command from the ignition box, so it must be OK. Not switching with the engine running suggests a duff ignition box. Perhaps you can borrow one that is known to be working properly to confirm?
"Mine is a long and sad tale", said the mouse.
"Indeed it is", said Alice, looking at the mouse's tail.

Mouser
Heavy Smoker
Posts: 118
Joined: Tue Nov 05, 2013 9:57 pm
Location: Luxemburg

Re: not rev'ing past7500

Post by Mouser » Wed May 30, 2018 6:59 pm

I do have 3 CDI's....tried them all.
Don't know anybody nearby with a KR1...

I tried them all 3 in winter when trying to solve out what was the problem in 2017.
I hope that I haven't f****up all of the 3 CDI's ?!?! Because I did have those "6V" on the coil with just the key turned.....(only later I found out that those 6V came from the RPM tacho) .

But then they would "behave" all 3 the same way (all 3 would have been "smoked" the same way)....wouldn't that be a bit strange??

Mouser

User avatar
Bertie_Mollie
Premix Junkie
Posts: 1304
Joined: Fri Apr 18, 2008 8:25 am
Location: Solihull

Re: not rev'ing past7500

Post by Bertie_Mollie » Wed May 30, 2018 7:30 pm

Are your pipes coked up?

I've had this before. Although having said that it did seem to rev normally in neutral.

Someone suggested this to me and I dismissed it but was out of ideas so tried a tatty spare set and it went off like a rocket.
GWB KR1s C2 - Now gone :-(
GWB KR1 - YES IT'S DONE!
AND NO S****Y H****A'S

Usque Ad Mortem Bibendum

Mouser
Heavy Smoker
Posts: 118
Joined: Tue Nov 05, 2013 9:57 pm
Location: Luxemburg

Re: not rev'ing past7500

Post by Mouser » Wed May 30, 2018 8:52 pm

No, not coked up.....would be a great incidence with the valves not turning and the power leaving at 7500rpm.....and the pipes be the reason....

Anyone has any idea what this could be else than the CDI....I don't really believe all 3 CDI's are screwed....any electric element that could be the reason?

IF the CDI would not get an info about the RPM state....would it be possible it fires correctly although no RPM info but not opening the valves?

@ADMIN: Could you move this topic to the electric subfolder?

thanks

Mouser

User avatar
Bertie_Mollie
Premix Junkie
Posts: 1304
Joined: Fri Apr 18, 2008 8:25 am
Location: Solihull

Re: not rev'ing past7500

Post by Bertie_Mollie » Thu May 31, 2018 9:19 am

Have you checked your voltage regulator? It's quite common that this fails and smokes your electrics including the CDI.

Won't fix your problem but could be a root cause.
GWB KR1s C2 - Now gone :-(
GWB KR1 - YES IT'S DONE!
AND NO S****Y H****A'S

Usque Ad Mortem Bibendum

Mouser
Heavy Smoker
Posts: 118
Joined: Tue Nov 05, 2013 9:57 pm
Location: Luxemburg

Re: not rev'ing past7500

Post by Mouser » Thu May 31, 2018 10:29 am

voltage regulator works fine....

Mouser

Post Reply

Who is online

Users browsing this forum: No registered users and 4 guests