Flat spot at 6rpm

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Sean1987
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Joined: Sun Apr 27, 2014 11:00 am

Flat spot at 6rpm

Post by Sean1987 »

Hi all got a problem with my storm when I Open the throttle fully on it when riding it sticks at 6rpm and the whole bike seems to judder but if I pull the throttle back slowly it goes past 6rpm and it Revs freely when when stood revving it
any help would be much appreciated
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VTRDark
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Re: Flat spot at 6rpm

Post by VTRDark »

First guess I would say timing 180 out. Have the cams been removed at all, front cct failure by any chance at some stage in the bikes life.

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Sean1987
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Joined: Sun Apr 27, 2014 11:00 am

Re: Flat spot at 6rpm

Post by Sean1987 »

Hi thanks for the reply I was told the CCT's were changed at 33k the bike has now done 46k I've got receipt to prove the they changed them but maybe they didn't time it right?
I've only had the bike about 4 month and when I first bought it it hardly revved until I took it out for a long test ride and it got better so I thought maybe it was dirty carbs so cleaned them and it just stayed at 6rpm still but carbs not been balanced so that might be it maybe ?
Sean1987
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Re: Flat spot at 6rpm

Post by Sean1987 »

Sorry meant to say it stuck at 6rpm then I cleaned the carbs and it was still same
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nt1980
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Re: Flat spot at 6rpm

Post by nt1980 »

New cct's can fail not long after fitting good idea to check the threads on this

As carl has said could be out of timing or has had a failed cct at some point

How long have you had the bike is it new to you ?
1998 black vtr (mods cbr900 fork conversion, ohlins rear shock, ohlins steering damper, prolite discs brembo master cylinder, goodridge braided lines, harris rear sets, Quick shifter,Mario Fairing, etc)
tony.mon
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Re: Flat spot at 6rpm

Post by tony.mon »

Agree with the previous post- this is classic cam timing 180 degrees out.

It's a simple enough check.
It's not falling off, it's an upgrade opportunity.
Sean1987
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Re: Flat spot at 6rpm

Post by Sean1987 »

Ok thanks only had the bike 4 month so guna check info on this 180 problem
Thanks
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VTRDark
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Re: Flat spot at 6rpm

Post by VTRDark »

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sirch345
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Re: Flat spot at 6rpm

Post by sirch345 »

I also agree, it certainly sounds like the valve timing being 180 degrees out. Don't follow the Haynes manual for correcting this, as for this particular job is slightly misleading.

This problem seems to arise when a CCT (cam chain tensioner) fails, the valve timing then in most cases needs resetting. Some mechanic's don't seem to realise the valve timing for the Firestorm's (the Superhawk in other countries) big V twin engine works differently than for an inline four cylinder engine. What appears to be happening in some cases is, a CCT fails, you take it to your local garage to get it repaired. The mechanic thinks he has to set the valve timing up for the failed cylinder, fit the new CCT and that's it, the trouble is that is not it on a Firestorm. Okay you do have two individual cylinders each with their own CCT I agree, but each cylinder needs to be timed with the other, that's where the confusion seems to be coming from, hence the 180 degrees out.

Chris.
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8541Hawk
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Re: Flat spot at 6rpm

Post by 8541Hawk »

nt1980 wrote:New cct's can fail not long after fitting good idea to check the threads on this
Or they can also work without any issues as long as they are replaced at the proper service intervals.
Personally I am about to hit 100K miles all with stock auto CCTs.

Carry on :thumbup:
Loud pipes don't save lives, knowing how to ride your bike will save your life.
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darkember
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Re: Flat spot at 6rpm

Post by darkember »

Not going down that route again Hawk :lol: :lol:
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Watty
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Re: Flat spot at 6rpm

Post by Watty »

8541Hawk wrote:
nt1980 wrote:New cct's can fail not long after fitting good idea to check the threads on this
Or they can also work without any issues as long as they are replaced at the proper service intervals.
Personally I am about to hit 100K miles all with stock auto CCTs.

Carry on :thumbup:
Lucky :lol: :lol:
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lloydie
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Re: Flat spot at 6rpm

Post by lloydie »

8541Hawk wrote:
nt1980 wrote:New cct's can fail not long after fitting good idea to check the threads on this
Or they can also work without any issues as long as they are replaced at the proper service intervals.
Personally I am about to hit 100K miles all with stock auto CCTs.

Carry on :thumbup:
Yes but you have had it from new and kept it in good condition and run it regularly .
It's these bike that have been stood for a while and only been run for a few minutes a month if that and then fail .

I'm a fan of the stopper mod myself just for piece of mind if they did fail it will save the valves and you keep the Aulto tensioning
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