my VTR appears to be back firing,

[Taz69]

Hi all,

I have a 98 VTR which has been sat for a year, I have drained the fuel put in some fresh fuel, the bike starts but it appears to have a back fire now when revving, it is in my garage on a rear stand at the mo.

The plugs were new last year, it has MIG high level cans on along with a stock filter, it was running fine before being sat up.

Any ideas where I should look first please peeps?

Thanks
Mark
Bristol

[bazza696]

Carbs might be out of balance, but to be honest, if i blip my throttle quickly a few times on the trot I can get her to pop and backfire..

you want to hear mine on over-run it sounds like a M60 backfiring, and mine has just be dyno'd and the mixture on idle is a little weak, but 3500 revs on is spot on for mixture, I have an air leak in the exhaust somewhere.

passed the MOT so I am happy to keep the popping, I look at it as she is talking to me.

[Taz69]

Thanks for the reply chap, I am just a little concerned about it, it may have done it before, its been so long since I rode her last I may have forgot.

Wheres the best place to get the carbs balanced, any ideas, regular motorcycle workshop or a tuning workshop?

Thanks

[gilson]

Check your exhaust first by giving the end cans a wobble and looking for any flex in the pipe at the links. Often it just needs lossening off, pushin back on and tightening up.

Firestorms do make some noise and it's even more noticable with aftermarket cans.

If it has been sat it's also likely that the carbs need a clean. It could be that some gunge has got under the float bowl cut off switch which causes too much fuel to be pushed into the carbs than nessecary, making it run rich. It's what happened to my track bike after winter. This caused it to pop a little more than usual and lose some power. I need to take them off, open the float bowl and give it a good clean with some carb cleaner. I've never done this, but it sounds easy.

Carb balancing is an easy job for a mechanic.

[bazza696]

Thanks for the reply chap, I am just a little concerned about it, it may have done it before, its been so long since I rode her last I may have forgot.

Wheres the best place to get the carbs balanced, any ideas, regular motorcycle workshop or a tuning workshop?

Thanks

Where do you live, there is a number of people on her that have the tools. My balancer paid for itself the second time I used it.

[Taz69]

Hi chap, I thought the carbs may have been dirty but first I thought I would run her up with some redex in the fuel to see if that helps, I have had her running for 30mins on idel and the temp gauge gets to just under 1/2 way, the popping/back fire tends to happen if I run her up to about 3/4k rpm and hold her for a around 60secs then I get a pop, regarding the exhaust, everything seems tight, if I hold my hands over the ends, the bike cuts out like you would expect.

I am not afraid of getting my hands dirty and I can certainly take and engine in and out of a car etc, its just that I have never had a go at balancing the carbs, lol, I mainly do any other repairs myself.
Its the 1st V-Twin I have had.

Mark

[Taz69]

Thanks for the reply chap, I am just a little concerned about it, it may have done it before, its been so long since I rode her last I may have forgot.

Wheres the best place to get the carbs balanced, any ideas, regular motorcycle workshop or a tuning workshop?

Thanks

Where do you live, there is a number of people on her that have the tools. My balancer paid for itself the second time I used it.

Hi mate, I live in Bristol, not far from the M5/M4

Thanks

[playerone]

Hi mate, I live in Bristol, not far from the M5/M4

Thanks

Cant be far from me then, but i'm not much use to anyone at the minute

[AMCQ46]

I am not afraid of getting my hands dirty and I can certainly take and engine in and out of a car etc, its just that I have never had a go at balancing the carbs, lol, I mainly do any other repairs myself.
Its the 1st V-Twin I have had.

Mark

if you search in the workshop section I did some photos and a "how to" when I last did mine.

I didnt cover taking the tank and airbox off, but I thibk you should be able to work those bits out no problem

[Taz69]

Hi mate, I live in Bristol, not far from the M5/M4

Thanks

Cant be far from me then, but i'm not much use to anyone at the minute

Hi mate, where abouts are you then? whats happened to you then?

AMQ, I have found the how-to thanks chap, I was hoping someone local might have a set and fancy a cuppa, lol.

Mark

[playerone]

Hi mate, I live in Bristol, not far from the M5/M4

Thanks

Cant be far from me then, but i'm not much use to anyone at the minute

Hi mate, where abouts are you then? whats happened to you then?

AMQ, I have found the how-to thanks chap, I was hoping someone local might have a set and fancy a cuppa, lol.

Mark

In Downend, had a slight spill on the Wales trip last weekend, have a look in the ride-out section for pics of damage

[Taz69]

Jeepers mate, glad to hear your okay though, thats good.

If there is anything I can do for you mate, give us a shout.

Mark

[pariah]

Just take it out for a good run and blow the cob webs out of her.

[AMCQ46]

my vote is air leaks, either on the inlet side [ with a perished rubber on the vac hoses etc] or exhaust connections.

as said, get it out and give it a good run to clear the pipes and get the plugs good and hot, then if still doing it, tank off and check all the pipes, then if not that check airbox for mice then carbs balance then carbs off and strip.

[Taz69]

Thanks for the replies guys, I have to get it MOT'd before I can take it out for a blast, I will have a look at the vacuum hoses I think, as I said it has been sat for a year so 1 may have perished a little.

Mark