Misfire - 3,500-4,000 RPM
- cliveyandrews
- Posts: 1041
- Joined: Tue Jul 07, 2009 9:01 pm
- Location: Tamworth, Staffordshire
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Misfire - 3,500-4,000 RPM
I've been riding Pauline's 'Storm for the last few days - and I've noticed a misfire/splutter around 3,500-4,000 RPM, usually after using more throttle/revs, backing off, then rolling on the throttle. It clears its throat with more Revs and throttle - and is fine at high revs or large throttle openings.
The bike had manual CCTs about a 1000 miles ago - and had to have the head off as the mechanic had the chain jump some teeth and bend valves (he is a qualified mechanic honest!)
It's had new plugs (iridium), at that 1,000 mile point, a very recent new battery and reg/rec. the bike has a K&N - but when I looked at the old plugs they weren't obviously weak.
Soooo - any thoughts? Anything obvious/known failure points that I need to check? (Do coils fail, any diaphragms fail?)
I can ride through it, but its Pauline's bike - and I need it to run right and be smooth for her to gain experience safely....
Cheers guys!
The bike had manual CCTs about a 1000 miles ago - and had to have the head off as the mechanic had the chain jump some teeth and bend valves (he is a qualified mechanic honest!)
It's had new plugs (iridium), at that 1,000 mile point, a very recent new battery and reg/rec. the bike has a K&N - but when I looked at the old plugs they weren't obviously weak.
Soooo - any thoughts? Anything obvious/known failure points that I need to check? (Do coils fail, any diaphragms fail?)
I can ride through it, but its Pauline's bike - and I need it to run right and be smooth for her to gain experience safely....
Cheers guys!
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Audi, Vide, Tace
aurantiacus tempestas es ocius
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Audi, Vide, Tace
aurantiacus tempestas es ocius
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Re: Misfire - 3,500-4,000 RPM
Try a normal filter if it hasn't been rejetted for the K&N.
When were carbs last balanced? Check for any air leaks in the intake/exhaust system. Is the vacuum hose intact and correctly placed.
When were carbs last balanced? Check for any air leaks in the intake/exhaust system. Is the vacuum hose intact and correctly placed.
It may be that your whole purpose in life is simply to serve as a warning to others.
VTR Firestorm and other bikes t-shirts
VTR Firestorm and other bikes t-shirts
- cliveyandrews
- Posts: 1041
- Joined: Tue Jul 07, 2009 9:01 pm
- Location: Tamworth, Staffordshire
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Re: Misfire - 3,500-4,000 RPM
I'll double check the vacuum hose. It was faultless until the CCT replacement - the workshop know Storms well and have done loads, so I'm not inclined to think something's been replaced wrong. I wonder if a coil could be going? I'm sure fuel is getting through. I'm gonna try another few tanks of fuel in case it's dirty - the bike doesn't do many miles - and stands around a lot....Wicky wrote:Try a normal filter if it hasn't been rejetted for the K&N.
When were carbs last balanced? Check for any air leaks in the intake/exhaust system. Is the vacuum hose intact and correctly placed.
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Audi, Vide, Tace
aurantiacus tempestas es ocius
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Audi, Vide, Tace
aurantiacus tempestas es ocius
=====================================================
- cliveyandrews
- Posts: 1041
- Joined: Tue Jul 07, 2009 9:01 pm
- Location: Tamworth, Staffordshire
- Contact:
Re: Misfire - 3,500-4,000 RPM
It's been suggested I pull the Iridium plugs for OEM spec...? (Mine runs fine on Iridium mind you)
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Audi, Vide, Tace
aurantiacus tempestas es ocius
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Audi, Vide, Tace
aurantiacus tempestas es ocius
=====================================================
- cliveyandrews
- Posts: 1041
- Joined: Tue Jul 07, 2009 9:01 pm
- Location: Tamworth, Staffordshire
- Contact:
Re: Misfire - 3,500-4,000 RPM
It's been suggested I pull the Iridium plugs for OEM spec...? (Mine runs fine on Iridium mind you)
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Audi, Vide, Tace
aurantiacus tempestas es ocius
=====================================================
Audi, Vide, Tace
aurantiacus tempestas es ocius
=====================================================
Re: Misfire - 3,500-4,000 RPM
Humm, they know their storms well even after bending your valves or was that another mechanic???cliveyandrews wrote:I'll double check the vacuum hose. It was faultless until the CCT replacement - the workshop know Storms well and have done loads, so I'm not inclined to think something's been replaced wrong. I wonder if a coil could be going? I'm sure fuel is getting through. I'm gonna try another few tanks of fuel in case it's dirty - the bike doesn't do many miles - and stands around a lot....Wicky wrote:Try a normal filter if it hasn't been rejetted for the K&N.
When were carbs last balanced? Check for any air leaks in the intake/exhaust system. Is the vacuum hose intact and correctly placed.
Re: Misfire - 3,500-4,000 RPM
Sounds like a carb strip is in order, and check the vac hoses when you have the airbox off beforehand.
And make sure the plug caps are properly pushed on....
And make sure the plug caps are properly pushed on....
It's not falling off, it's an upgrade opportunity.
- cliveyandrews
- Posts: 1041
- Joined: Tue Jul 07, 2009 9:01 pm
- Location: Tamworth, Staffordshire
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Re: Misfire - 3,500-4,000 RPM
Same mechanic. I do trust him. sh1t happens - and he rectified it all. I'll even go back to him if I can't find an answer....
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Audi, Vide, Tace
aurantiacus tempestas es ocius
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Audi, Vide, Tace
aurantiacus tempestas es ocius
=====================================================
- cliveyandrews
- Posts: 1041
- Joined: Tue Jul 07, 2009 9:01 pm
- Location: Tamworth, Staffordshire
- Contact:
Re: Misfire - 3,500-4,000 RPM
I'm thinking crap in the carbs. It's the erratic nature of it. Like a block in a pilot jet?tony.mon wrote:Sounds like a carb strip is in order, and check the vac hoses when you have the airbox off beforehand.
And make sure the plug caps are properly pushed on....
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Audi, Vide, Tace
aurantiacus tempestas es ocius
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Audi, Vide, Tace
aurantiacus tempestas es ocius
=====================================================
Re: Misfire - 3,500-4,000 RPM
[I'm thinking crap in the carbs. It's the erratic nature of it. Like a block in a pilot jet?[/quote]
I would try carb cleaner first
I would try carb cleaner first
Duffy1964
Yellow 1997 Storm R.I.P. Orange 2000 Streetfighter (Rufus), Red & Silver 1968 Triumph Trophy 650, Blue 2003 Storm Project, Red 2007 Montesa Cota Trials 250 & 1959 BSA D7 175cc Bantam Trials Project
Yellow 1997 Storm R.I.P. Orange 2000 Streetfighter (Rufus), Red & Silver 1968 Triumph Trophy 650, Blue 2003 Storm Project, Red 2007 Montesa Cota Trials 250 & 1959 BSA D7 175cc Bantam Trials Project
- cliveyandrews
- Posts: 1041
- Joined: Tue Jul 07, 2009 9:01 pm
- Location: Tamworth, Staffordshire
- Contact:
Re: Misfire - 3,500-4,000 RPM
Well - I pulled the carbs off and apart last weekend. Some gunk in the rear main, but that's it. Cleaned the bowls etc, but by then my back was fooked, so no test run. If I can drag my lazy butt out of bed I might stick some miles on it this morning.
Make sure it's ok for RTTW next week....
Make sure it's ok for RTTW next week....
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Audi, Vide, Tace
aurantiacus tempestas es ocius
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Audi, Vide, Tace
aurantiacus tempestas es ocius
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Re: Misfire - 3,500-4,000 RPM
So was that the outcome to the problem ? Crap in the carbs.
Re: Misfire - 3,500-4,000 RPM
Clive was last on here in 2016 mate, so you may not get a response.
Carpe diem, quam minimum credula postero
F3, 954 USD front, K Tech springs, Braced swinger, Penske shock, Six spoke Mockesini wheels, Harris rearsets, QaT, Flywheel diet!, A&L stacks, stick coils, K&N, FP Ti jets, lashings of Ti & CF
F3, 954 USD front, K Tech springs, Braced swinger, Penske shock, Six spoke Mockesini wheels, Harris rearsets, QaT, Flywheel diet!, A&L stacks, stick coils, K&N, FP Ti jets, lashings of Ti & CF
Re: Misfire - 3,500-4,000 RPM
Hi kev, Thanks for you're reply. I did notice it was a while back the thread was on here but thought I would chance my arm to see if I got a response. Im assuming that was the outcome as he didn't return to ask anymore questions. Its a shame he didn't post the outcome for others to see. Cheers m8
Re: Misfire - 3,500-4,000 RPM
my yellow one had the same problem. new plugs and all. but when i changed the few hundred miles old plugs for another set it cured mine. dont trust new plugs
the older i get,the faster i was