Popping when closing throttle

[baldyshinehead]

When i close the throttle i get popping through the pipes, 3 or 4 pops, very loud, sounds like a shotgun . When the speed drops it stops or if i change up as i drop the revs.
Thought it was air getting in somewhere but have checked that and there are no gaps anywhere on either pipe.

Dragqueen V-star 1100.
Highway hawk pipes.
I have no idea if the carbs have been touched but it is the standard air box.

Any ideas :confused:

http://i51.photobucket.com/albums/f363/baldyshinehead/HPIM2276.jpg

[bigg]

It sounds like it is running a bit rich. As there is an aftermarket pipe it could probably do with the carbs setting up. Better to be to rich than running lean as this could scar your valve seats.

[Creature]

Better to be to rich than running lean as this could scar your valve seats.

I disagree here running too rich can remove the oil from teh bore liners causes excessive and premature bore ware

[BigBod]

One of my bikes did this, I balanced the carbs and changed the air filter for a K&N, problem solved.

[Pugwash]

Poppin usually means it's running too weak not rich as in it's getting too much Air ,

have the pipes got any baffles ?

as a rule turn the mixture screws in a 1/4 to 1/2 a turn each that'll make it a bit better but a Dyno Run with a CO2 probe stuck up it's arse will be the best thing for it

[Peirre]

its the "motorcycle farkle" that done it :D

[minxy]

Get it onto a dyno and see what the air fuel mix is doing. Have you got flames too?

[krammer]

My VTX18 does that with the Vance and Hines pipe's, i reckon it sound's fuckin' brilliant especially riding through Handsworth watchin' all the Darkies diving for cover :thumbsu:. Back to the point though removing the pare (sp?) valve rectifies the popping and banging issues :)

[baldyshinehead]

Get it onto a dyno and see what the air fuel mix is doing. Have you got flames too?

I will have to look to see if we have a dyno place nearby, and no flames as far as i can see, just very loud bangs :p

I have been looking at the v-star1100 forum and they recommend removing the AIS ( i think it was ). I had a look where it should have been and it isnt there, so looks like it has been removed allready. Obviously didnt fix the problem :rolleyes:

I wouldnt mind if it just popped once but its 3 or 4 times each time i shut the throttle and im worried it is doing harm somewhere.

[willie2006]

i had that problem, got me carbs balanced problem sorted. :thumbsu:

[krammer]

Has the V star got carb's?

[baldyshinehead]

Has the V star got carb's?

Yes.

You have to strip half the bike to get to them but they are there.

[minxy]

There's a dyno in Stevenage that I can highly recommend - SDC Performance. Give em a call on 01438 357 777.

[kwakerkeith]

mines been popin n banging for about 3 years n even set fire to me throw overs once(ooppps) but thats down to an air leak between the can and down pipes,,,,,sounds good goin down the hill in to matlock between some big stone walls:unsure::unsure:

[baldyshinehead]

There's a dyno in Stevenage that I can highly recommend - SDC Performance. Give em a call on 01438 357 777.

thanks Minxy :thumbsu:


Keith, if i went between big stone walls i would be heard about 3 miles away :o

[minxy]

For the price of a run, it's worth putting your mind at rest mate. That's a spanky clean bike you've got yourself there ;) :thumbu:

[XJphil]

Could be the exhorst gaskets, if new one wern`t fitted when pipes were put on, some folks don`t and use the old ones, then air could be leaking in through there causeing popping on the over run
for the coast of zorst gaskets its worth trying

[baldyshinehead]

Could be the exhorst gaskets, if new one wern`t fitted when pipes were put on, some folks don`t and use the old ones, then air could be leaking in through there causeing popping on the over run
for the coast of zorst gaskets its worth trying

I put new ones in today

[ChopperFXR]

This is a problem I have been asked to solve several times recently, all on jap cruisers.

Check the pipes for air leaks, including fitting new gaskets if that has not already been done. If you are sure there are no air leaks on the pipes, check your airfilter box.

Not done one of your particular model, but I know some of them have wierd electronic sensors. You need to check with whoever made the pipes if these things have to be removed, upgraded or altered in any way.

Check your mixture and balancing. You may need to alter the main jets. None of these things are expensive, but some are time consuming. If you do not have access to a rolling road/Dyno, its a case of trial and error.

Sorry to sound vague but there are so many variants. Some remedies work on some but not on others. Look for the most simple things first.

Good lcuk

Chopper.

[krammer]

These chap's might be able to offer a few pointer's...




http://groups.msn.com/yamahastarclub/1100vstartech.msnw?action=get_message&mview=0&ID_Message=17012&LastModified=4675632353771519577

[baldyshinehead]

Balanced the carbs, checked the mixture, did everything possible and it all made no difference.
So i gave up and put the original pipes back on, with one or two mods done to them first ;)
No popping now, not as good a sound but its better than stock.
Thanks for the help everyone.

[kitkatman]

Balanced the carbs, checked the mixture, did everything possible and it all made no difference.
So i gave up and put the original pipes back on, with one or two mods done to them first ;)
No popping now, not as good a sound but its better than stock.
Thanks for the help everyone.

bloody hell gal, bet she looks different....thanks for the tea yesterday, nice to catch up with you and yours again, lee's done a bloody good job on that 125 mate, i was well impressed:D

[baldyshinehead]

Chears kkm, the bike does look different without them pipes, but i do like the looks of the standard ones now i have cut a few inches off the back :D
Lee loves that little bike and he is getting more and more confident on it, he will be happy to hear you liked what he had done.

[baldyshinehead]

Just had a look on the highway hawk site, turn down pipes the same as i have just taken off are £500 :eek:
Think i will have to do a little more research on fixing the popping :D

[kitkatman]

Lee loves that little bike and he is getting more and more confident on it, he will be happy to hear you liked what he had done.

he's done bloody well with it mate and good on him.......sorry if i upset one of your neighbours yesterday as i left, if he wouldnt have moved his car over i was going to knock his teeth out as the silly fucker decided he was a continetal driver and drove of my side of the tarmac:D

anyway, do you think the bikes loud enough:eek::thumbsu:

[Sir Ewok]

What about ignition, I know most modern bikes are all electronic, but altering the ignition timing may help. If you do not get the negative pressure wave back from the tuned length pipes, then the cylinder may not be scavenged properly or the valve may be opening too soon. Worth a check if all else fails.....:unsure:

[erizo]

if you´ve got chromed shiney pipes of around 12mm diameter running down the other side of the engine with some rubber unions near the sidepanels, that´s the ASI plumbing. to disactivate it, i normally take off the rubber pipes, stick an M10 bolt in the tube, then put the pipe back. this does NO damage.

depending on how much popping there is on the overrun, you should be able to get rid of it using the PMS screws. DON´T arse about with the ignition!

check for air leaks on the carb side. a short squirt of carb cleaner or WD round the rubbers with the engine running will tell you if you´ve got an air leak with an increase in revs. at the exhausts, hold a piece of paper near the head exhaust clamps and rev the engine. if it flutters, it´s blowing, so fit new gaskets.

[baldyshinehead]

Thanks erizo, and thanks to bosun for checking with a few people to see if the UK models had AIS, which they dont, so thats not it :p
Have checked all the areas is could be leaking, no leaks anywhere.
Balanced the carbs and while i was able to get to them played around a little with the PMS screws, Out made it worse, in made it better but wouldnt stop it and screwing them in far enough to make a difference on the backfire it wouldnt idle.
I will crack this sooner or later :D

[odie]

Try this: http://www.mikuni.com/fs-tuning_guide.html it might point you in the right direction

[baldyshinehead]

Try this: http://www.mikuni.com/fs-tuning_guide.html it might point you in the right direction

That explains it so much better than anyone has so far, thanks odie

[odie]

Was i helpfull?:eek:
Makes a change if i was!:D

[baldyshinehead]

Yes. get yourself a cookie :D

Fixed the problem today, found an old baffle, cut it into 2 bits about 4 inches long, shoved into end of pipes and welded in place.
No loss of sound, still nice and deep, a little loss in volume but nothing to shout home about and very minimal backfire :D
Happy bunny now, i can wake up the neighbours again at 6am :p

[Grav]

What a thoroughly useful link, Odie, are you ill?:D

In fact, it's so useful that I am putting it in it's own thread in the workshop forum and making it a sticky.:thumbsu: