Kelum

Hi guys, I set up a 6mm gap between two electrodes on a circuit board to check the spark quality, and cranked the engine, the spark wasnt orange it was blue and was well defined..however, the spark goes well and after say 30secs of run the spark stops...the running cylinder too slowers, that means same thing happening in the other plug also...thats why I experienced a stop in both cylinders when riding. After this stop spark occurs again and the engine runs...so I know now the ignition coils could be the next suspect, is it possible for both coils to behave the same way like this, or is it the TCI unit or the connectors in between two keep killing me? Been going through Hyenes V twins manual and I picked up the idea. Will check coils next n keep u guys posted...please advise on the issues I have raised here... So now I know there's a problem with ignition system but not with the fuel system....the bike had some sighing like thing anyways since the times I bought it...so it must have had the problem developing or like this even then I guess..

The engine has run around 48000km by now. At this point coils can be malfunctioning, sure I will check coils tomorrow. Will let you know, in the mean time please guys make sure you drop in stuff that come into your mind here on my particular issue...thanks a lot..

The engine mercilessly cuts down power specially when u slower the bike in low gear..its like both cylinders stop together..yes it is because bike suddenly becomes silent and again she runs..silent because both cylinders stop..this happened several times now...am thinking of carburetor checkup by myself, can someone guide me, may be with some photos? tell me what I should do and what I shouldnt..? plus I think I must adjust tappets too, is there O-rings with the bolt caps on tappets? for this I must completely remove gas tank and keep it away I guess...no room otherwise..any help appreciated..

Now am thinking the same, I must remove petrol tank and check filters if they are blocked and water trapped. Plus must check coils too. You can ride for around 100 meters and there's some stop in the engine and the speed maintained due to previous pushes and it starts again, seemed this miss was periodic, anyways if it were a fuel issue the miss shouldnt have been periodic..? am wondering if there is a problem with current flow to ignition coils or they themselves behaving naughty? how would u normally check coils with a multimeter anyway?

Had a ride, bike feels powerful, still at times I feel misses, plus when u decelerate engine stops. What would be the areas I should look into?

I connected new wires to ignition coils, removed faulty plug caps and put NGK new ones. Gonna have a ride n see..the wires were not glued to coils..

When I was dealing with cables I felt like they were rotating at the coil end, so I think they are removable, will do that anyways...I think I should put some glue after fixing in order to avoid moisture get in..thanks mate

Thanks Ray and all...buying leads what amperage etc I should consider...? yes Ray you have a good memory..thanks!

I cut around 12mm off the front cylinder wire, holy shit all the copper wires had pale blue stuff along them...I think the wires should be replaced and may be they resist current flow? according to this replacing is a piece of cake. http://www.ehow.com/...virago-535.html Can I use any set of wire or is there some particular amperage for xv125? After cutting off still there is a slight miss I think because copper oxide running along the total length of wire thats why? I have never been able to keep bike running at idle, I mean let engine run without me having grip on accelerator. (hope I gave the idea, how do you say that?)

Why does it have to be 12mm? I cut off some in other cylinder, will do in the front too, but what if wire shortens by and by, will I be able to buy one and hook it up to the ignition coil...even today I noticed missfire is very prominent when you slower the bikey..

Guyz just checked resistance in both caps at 20k setting on multimeter. The standard being 5k I'm getting 10.52 and 10.12k for plugs. The 10.52k reading comes from the cap with the sooty carboned plug... What the hell is going on...the resistance is almost twice, does this mean the voltage plugs getting is way too low? what should I do? and Ray one cable is not long enough to reach other cylinder so swapping coils not possible. Like I mentioned swapping plug caps worsened the issue...there was copper oxide at coil wire - plug cap (screw) end which scraped off...

OOooh buddy u just killed me, would this relate to piston rings etc? I hope not..yes I will compare two and see, sooty carbon wasnt very much, but yes something's wrong..am scared..

Hi buddy, will check all and tell you..I did this today, I swapped the plug caps and the miss grew wilder I couldnt ride her even...then I changed caps back again and worst became bad. I read this article too..anyway will try and see tomorrow better and update u..please be there for me.. http://www.viragoownersclub.org/Dr%20Piston/ignition.htm

Plus when I accelerate the bike at neutral...I get heavy smell of some oily/petrol vapor...is that normal, its coming from the exhaust pipe opening behind rear cylinder for sure..does this mean improper combustion? probably misfiring causes unburnt gas vapor to emit from pipes? My bike doesnt have a sidestand switch too, how can I locate switch connectors? Am lost please help..

Hiya guyz, Been offline for a while was tied down with work...so hope all the guyz doing well.. Would you guys tell me how would you identify faulty plug caps with a multimeter or any other means? My engine's got a lazy start, a heavy misfiring going on in front cylinder..like it fut futs doing well at lower gears. However you can still ride, the issue starts to appear right after you slower the bike in order to turn or at a zebra crossing. I have to accelerate greater than usual in order to make her move right after some stop. I checked spark plugs and the front cylinder had sooty black carbon build-up but the sparking points were clean at the gap, carbon build-up was around 20% which I think is normal? The rear cylinder had no carbon at all and the combustion seems to be good. Both spark plugs are new and genuine NGK made for Yamaha. I saw on the net there is a resistor in plug caps, may be its damaged, I tried to check continuity in caps but no reading came out in multimeter. Is it possible misfiring to come with bad plug caps? The misfiring comes all the time right after washing the bike or riding in the rain. In that case also engine starts to fut fut at low gears but sometimes at the 1st when I accelerate more the bike moves speedily. May be faulty ignition coils? How can I check them with multimeter? There is a sudden brightness increase in the headlight also, it comes on and off, sometimes the brightness remains for several minutes and reduces... Does my bike having a serious issue, have you guys come across the same? can oxide buildup in plug caps or something cause this? Faulty rectifier? or battery? Please help me..thanks guyz!

Yep cant see a thing clear..

Thanks mate..will have a look once oils and everything ready..I think its wheels but could be brushes too..i have this US product called ABRO grey 999 gasket maker..mm anyway it can withstand upto 343 Celsius only..is it ok? sensor safe and non-corrosive it says..have u come across it, is it good?

Hello Guys after long time.. My bike's starter motor making a very rusty CRAAAASH noise when I hit the start button every time..sometimes the motor or the wheels in its gear set seems to be like very rusty and motor appears to struggle to rotate them...could be the wheel set or the brushes of the motor.. I am thinking of disassembling the motor and its wheel set attaching the flywheel/ engine. Has any of you ever done this? Is it tough to do by myself? Please someone give me necessary guidelines..I think I should brush off the oxides on copper/metal surfaces in motor.. Ur help greatly appreciated Am reading this but I would like yo to share what know on xv125 starters http://www.vsocxv.co.uk/workshop/virago/starter.html Thank you!

I removed existing battery fluid, added some egg shells to see the strength of the fluid, verrrry weak bubbling...what a way to check acid strength when a hydrometer isnt around I refilled the battery with sulfuric acid..voltage rised up to 11.8..now a bit strong but when reving still the voltage remains same.. Battery or reg/rectifier..what if I charge the battery first?

Duplicated thread, please admins remove one, dont know how to

Hi guys, I put a new battery while ago and drove for a week, but suddenly lights went flickering and I removed the battery to find out all the acid in it gone. I filled distilled water into cells and had to ride for a week or so refilling when the fluid level went down, I didnt rev engine too much during this period as I had guessed the rec/reg was faulty. I put a new rec/reg and checked voltage regulation with multimeter. It was working. But the lights specially headlight and front signal lights were and are still very dim. But self-starter working. One night however when I was riding, all the lights went off..nothing was functioning, horn was very week and I felt misfires in the engine..so the ignition system too was struggling. I refitted the reg/rec socket and the problem solved. However the lights and signal etc very weak. Starter working. I checked all the connectors they are ok...I checked voltage regulation by rectifier today at battery terminals and THE BATTERY VOLTAGE NEVER GOES UP..MULTIMETER SHOWS 11.65V all the time...I checked white wires coming from stator and they dont have shorts to crankcase and they have a good AC flow. I have assumed following. 01. Reg/rec regulating the voltage, means its functioning properly as it heats up and charges the battery. The white wires too heat up during engine run. 02. Battery has become too weak..it doesnt charge well, it doesnt even reach 12 V...may be the acid is not strong... What should I do to strengthen up the battery? no means to check specific gravity, should I pour out some of the remaining liquid in battery and put some sulfuric? Please help guys, I think battery is damaged during my rides with earlier non-functioning reg/rectifier..

Hi guys, I put a new battery while ago and drove for a week, but suddenly lights went flickering and I removed the battery to find out all the acid in it gone. I filled distilled water into cells and had to ride for a week or so refilling when the fluid level went down, I didnt rev engine too much during this period as I had guessed the rec/reg was faulty. I put a new rec/reg and checked voltage regulation with multimeter. It was working. But the lights specially headlight and front signal lights were and are still very dim. But self-starter working. One night however when I was riding, all the lights went off..nothing was functioning, horn was very week and I felt misfires in the engine..so the ignition system too was struggling. I refitted the reg/rec socket and the problem solved. However the lights and signal etc very weak. Starter working. I checked all the connectors they are ok...I checked voltage regulation by rectifier today at battery terminals and THE BATTERY VOLTAGE NEVER GOES UP..MULTIMETER SHOWS 11.65V all the time...I checked white wires coming from stator and they dont have shorts to crankcase and they have a good AC flow. I have assumed following. 01. Reg/rec regulating the voltage, means its functioning properly as it heats up and charges the battery. The white wires too heat up during engine run. 02. Battery has become too weak..it doesnt charge well, it doesnt even reach 12 V...may be the acid is not strong... What should I do to strengthen up the battery? no means to check specific gravity, should I pour out some of the remaining liquid in battery and put some sulfuric? Please help guys, I think battery is damaged during my rides with earlier non-functioning reg/rectifier..

reg/rec is faulty men, it doesnt regulate the voltage being produced so the battery is being overcharged, it heats up and when all the liquid/acid is turned into sulfer dioxide...it explodes.. There are many threads here and elsewhere on this, the overcharging is more pronounced when u drive at higher speeds when rec/reg malfunctioning. put a new battery, put a new reg/rec , then hook up a multimeter to battery terminals and start the bike, the voltage should rise up but should remain around 13.5 volts, that means the voltage being regulated..if it rises upto 17, 18 volts..then reg/rec is bad...

Please explain how can I check the earth buddy? U mean the earth lead connecting from battery to crank case? or are you referring to the earth lead connected to the heat sink of rectifier/regulator? please advise!

Mulitimeter gave an 18.1 voltage reading at medium revs on battery terminals. Bad rectifier/regulator...