davehill1974 Posted July 3, 2014 Share Posted July 3, 2014 Hi all, I have just bought a Virago 750 with Silver Tail (thats the make not the colour) pipes, baffles removed. The bike runs as it should with the exception on the pop pop pop. Now I know to expect "some" popping but this is pretty constant at low revs in 30 zones or when decelerating. Also at low speed/revs she can be a bit jerky like almost die, then accelerate. The carbs have been completely stripped and re-furbed. I am getting them synched at the weekend. I don't think that the carbs have been re-jetted and the standard filter is fitted. From what I have read online the mix is set at Yam factory and should not be messed with.. Is that correct? I don't know much about tuning i'm afraid so please could somebody advise on what should be done to try and make her run a little smoother? I really don't want to have to fork out for another set of pipes. If it can be helped. Thanks very much in advance. Dave Link to comment Share on other sites More sharing options...
Noise Posted July 4, 2014 Share Posted July 4, 2014 Hi Dave, welcome to the forum, it also is a good ifea just to pop into the new memebr section later and introduce your self to the masses. Best thing to do mate is to pull out your spark plugs and check them. if they are jet black and i mean like if you'd just dipped them in a bucket of soot then your running the bike too rich (too much fuel) and your need smaller main jets. If the plugs are white then you are running too lean (not enough fuel) and need bigger main jets. My big pops and farts all the time on over run and spits the odd flame now and then but i litrally have straight through pipes and ram filters on the carbs and the only issue i get is a slight flat spot mid range in the revs. Link to comment Share on other sites More sharing options...
davehill1974 Posted July 4, 2014 Author Share Posted July 4, 2014 Hi Noise, Thanks for the reply I will check out the plugs later then. Yeah I will go to the new members section and say hi in a minute. 1 Link to comment Share on other sites More sharing options...
Noise Posted July 4, 2014 Share Posted July 4, 2014 other thing you could consider is a set or 4" long baby baffles, i have them for my bike just for MOT perposes but these knock out the back fireing too. also check your inlet manifolds, these are rubber and tend to crack and let in extra air which again can course to popping. Link to comment Share on other sites More sharing options...
davehill1974 Posted July 4, 2014 Author Share Posted July 4, 2014 Hey again, Yep I have checked all of the rubber inlets for them being too brittle. No sign of that, that I have noticed anyway. I'm getting the carbs balanced tomorrow so I will let everyone know how that goes. I was looking at the plugs earlier as suggested and one of them had a loose top bit (the nipple) don't know if its made a difference but I swear it runs better since i tightened it up. The plugs were a reddy brown colour, A bit of soot build up on the bottom of the thread but thats it. There is a biker friendly MOT place near where I live and he doesn't care how loud your bike is a lot of the locals go there.. Staffs police tend to not care too much either, or at least i've never been pulled yet! Link to comment Share on other sites More sharing options...
Preload Posted July 5, 2014 Share Posted July 5, 2014 Generally popping on the over run is air getting into the cans and igniting the unburnt fuel. I would sort out the fueling at low speed first as it sounds like its rich and as Noise said get a pair of baffles, apart from reducing the noise they will help reduce the air coming in.. 1 Link to comment Share on other sites More sharing options...
KevtheRev Posted July 5, 2014 Share Posted July 5, 2014 You could also replace the exhaust sealing rings at the cylinder heads . If they weren't replaced when the exhaust was changed they could be leaking air and this also causes popping on the overrun . They only cost a quid or so . Link to comment Share on other sites More sharing options...
davehill1974 Posted July 5, 2014 Author Share Posted July 5, 2014 Thanks preload, I checked that and you can feel the air getting sucked in. I have for some baffles coming in the week to see if it makes a difference, I hopefully won't loose too much volume though! Kev, yeah I have just ordered a couple of those too. The cans are slip on but I would say that as the bike is 22 years old somebody will most likely have had the header pipes off at some point so for what they cost may as well do it! I noticed a small hole on one of the joins earlier whilst balncing the carbs that is now sealed. seems to have made a slight difference. So at least were going in the right direction! Thanks all. Link to comment Share on other sites More sharing options...
davehill1974 Posted July 12, 2014 Author Share Posted July 12, 2014 New Spark Plugs and some home made baffles appears to have solved 99% of the issue Thanks everyone 1 Link to comment Share on other sites More sharing options...
KevtheRev Posted July 12, 2014 Share Posted July 12, 2014 Sound ! Link to comment Share on other sites More sharing options...
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