MISFIRE Steady riding 30mph 2nd gear 3000rpm HELP

[CouncilBacchus5]

Hi,

I have just bought a 2005 VTR Firestorm 12000 miles on the clock (and looks to be in standard condition) and have a small issue that when riding along at roughly 30mph, 2nd gear, 3000rpm there is an intermittent misfire then the bike will be fine for about 10 seconds (approx) then do it again.

This does seam to go away / not be as bad once the bike is up to full working temperature (after 10 mins start stop riding)

Also the bike accelerates and decelerates as you would expect without misfire. Only misfires when at constant throttle opening at slower speeds.

This misfire also occurs if you try and hold the throttle at 2-3k rpm while idling. Again when the engine is not fully warmed up.

Is this normal for a storm?

Do I just need to get used to it and let the bike warm up fully?

If not what could be causing it?

Thanking you in advance for your help.

[MacV2]

Hi,

I have just bought a 2005 VTR Firestorm 12000 miles on the clock (and looks to be in standard condition) and have a small issue that when riding along at roughly 30mph, 2nd gear, 3000rpm there is an intermittent misfire then the bike will be fine for about 10 seconds (approx) then do it again.

This does seam to go away / not be as bad once the bike is up to full working temperature (after 10 mins start stop riding)

Also the bike accelerates and decelerates as you would expect without misfire. Only misfires when at constant throttle opening at slower speeds.

This misfire also occurs if you try and hold the throttle at 2-3k rpm while idling. Again when the engine is not fully warmed up.

Is this normal for a storm?

Do I just need to get used to it and let the bike warm up fully?

If not what could be causing it?

Thanking you in advance for your help.

Hi there, do you still have the pairs gubbins fitted ?

This can give the symptoms your describing.

Mine does it as well, it has had the pairs gubbins removed but I think there is an air leak causing the poor running.

The pairs gubbins is the ''air quality'' crap fitted to the later models to satisfy the US market air quality regs.

Other things to consider...tick over revs, turn them up to 12000 rpm, easy to do it may cure it a bit...Carb balance...check the air filter & change if ness, at that mileage it may never have been changed.

Start with the easy things...tick over, air filter.

[CouncilBacchus5]

Thanks for your reply.

I have fitted a new air filter and spark plugs but not had chance to test it yet. The old air filter was black with dirt.

My bike is a UK model. Will it still have the "pairs gubbins" if so where will I find it?

Once warmed up the bike ticks over at 1200rpm already but does have a slight flutter in the revs at tick over.

If the air filter and plugs doesn't fix it I plan to take the carbs off to clean them out and check all the fuel lines and make sure I don't have any air leaks anywhere. I just need some good weather the give it a go.

How long does it take a VTR to warm up so that you can expect normal riding without any lumpiness in the engine. Please forgive my ignorance its been a while since iv had a bike with carbs and I am struggling to get used to the quirks.

Thanks.

[MacV2]

Unless your bike is a very very late reg. it will have pairs system fitted from new...but a PO may have taken it off...

It's officially called the ''air suction valve''

http://www.bike-parts-honda.com/pieces- ... STORM.html

It fits under the air box & plumbs in to the rocker covers. If its been removed you should have some blanked off pipes unless early model covers have been fitted.

Before you strip the carbs off for a clean get them balanced up first...read this...http://www.vtr1000.org/phpBB3/viewtopic ... 31&t=18430

The other thing that springs to mind is that it may of been re jetted at some stage for different pipes & not be std jetting. Has it got standard exhaust on it or after market jobbies...?

[CouncilBacchus5]

Its still go original cans on it. that's not to say that previous owner didn't swap it back to standard before getting rid so may still have been jetted. Is there any way to tell?

[MacV2]

Its still go original cans on it. that's not to say that previous owner didn't swap it back to standard before getting rid so may still have been jetted. Is there any way to tell?

Only by stripping the carbs down & checking the jets...

[darkember]

If you want to remove the PAIR system follow the procedure below, with easy step by step photos. In all fairness if should not miss a beat no matter what revs you are doing. My 2002 model doesn't which does beg the question that you may have a vacuum leak.

http://www.vtr1000.org/phpBB3/viewtopic ... ir+removal

[gabi81]

Mine used to do same but mine is a late model ...tps+carb balance sorted it

[bazzashadow]

Mine used to do same but mine is a late model ...tps+carb balance sorted it

mine does the same
98 model
cleaned my carbs and balanced them but still got the problem
what is tps?

[gabi81]

Mine used to do same but mine is a late model ...tps+carb balance sorted it

mine does the same
98 model
cleaned my carbs and balanced them but still got the problem
what is tps?

Throttle position sensor

[kev64]

Yeah, could be the TPS as this affects low cruise speeds, as has been said,read the guide, its pretty easy, I managed to do mine with the carbs in place

[tony.mon]

Use more revs.
Open throttle wider.
Enjoy

[CouncilBacchus5]

I thought that might be the answer. There is a chance that there isnt really an issue at all. I know vtr's have a reputation for been terrible to ride at low speeds. So is what I am getting normal and do I just need to ignore it until the bike is fully warmed up? The Tps is a possible fix for me to consider if I do jave an issue.

[popkat]

I thought that might be the answer. There is a chance that there isnt really an issue at all. I know vtr's have a reputation for been terrible to ride at low speeds. So is what I am getting normal and do I just need to ignore it until the bike is fully warmed up? The Tps is a possible fix for me to consider if I do jave an issue.

I don't think it's normal, you can ride round it though. I used to own the bike Mac mentioned in his earlier post, it did it with me but not when I first had it, I thought it might have been the pilot screw settings with the big bore pipes I had.. It would take about five miles riding then the bike would work perfectly, to get round those first five miles I used to ride with the choke still out a little bit, this made it smooth.

[VTRDark]

Once warmed up the bike ticks over at 1200rpm already but does have a slight flutter in the revs at tick over.

Mixture. It's a fuelling issue not a misfire as in electrical, missing a spark. Take note of the rev needle as it drops back to zero. Does it drop below and pick back up or hang and drop to zero.
http://www.vtr1000.org/phpBB3/viewtopic ... 14#p238528

As has been said TPS/carb balance does help alleviate the issue but it's not the complete solution. Is it the standard filter your running or a higher flowing filter.

Have look through the Read Me for New Members below and you will find lots of info and direction there.

(:-})