jimmy Posted August 3, 2013 Posted August 3, 2013 Alright folks My boy informed me today that his virago is not running properly. He says it will not pull away properly and struggles to get over 60, or indeed up a hill. Before I start panicking about the CDI Unit, I'm going to check the carb bowls, plugs etc to eliminate the obvious. Just heading out to nightshift, so while I'm away any other thoughts/opinions will be welcome. Sorry for the vague symptoms, but I've not had a chance to ride the bike myself
dt502001 Posted August 3, 2013 Posted August 3, 2013 Well the cdi unit would be my last thought. Pluged air filter,fouled spark plugs/HT leads,crap in the carbs,compression test first points to check,if it's running the the cdi unit is working. Sounds more like running on 1 cylinder. But as you said vauge symptoms,good luck sorting it out.
neversaydie Posted August 3, 2013 Posted August 3, 2013 Clutch slipping Weak spark Low compression Wrong mixture Over heavy mech load
jimmy Posted August 4, 2013 Author Posted August 4, 2013 Thanks for the replies folks, I'll get a few hours kip then have a look Well the cdi unit would be my last thought. if it's running the the cdi unit is working. dt In my experience and as the song says, 'it ain't necessarily so' His last bike went through 2 cdi units, granted, with the first one the bike wouldn't run, but with the 2nd unit the engine slowly lost power and would struggle to get the revs up.
dt502001 Posted August 4, 2013 Posted August 4, 2013 Just got back from a loooooong ride up to the beach's of lake hurron about 6hrsriding and 2-3 having dinner and a bit of tourest shopping with my GF and your just getting off work THAT SUCKS for you. I know that 1 in a1000 that the cdi unit fails slowly thats why i said last thought hopefully it just a bad spark plug or something simple
jimmy Posted August 4, 2013 Author Posted August 4, 2013 Cheers mate Yea before his last bike failures, the cdi would have been my last thought, but usually now it one of the 1st things I think about. Now just about every 'running issue' post on here, I think cdi.
jimmy Posted August 4, 2013 Author Posted August 4, 2013 Just back from a wee blast on it. Got the bike up to 75mph which is not bad as its restricted to 33bhp Under hard acceleration in top it has a bit of hesitation and an occasional backfire At one point there appeared to be a bit of clutch slip around 50-55 Finally gear linkage appears stiff. Ive ordered new filters, will pick up plugs and give the bike a good service. He still has his leak around the starter motor, so I've picked up an O ring as well and will get that sorted. I'm of the opinion that a good service is what it needs
jimmy Posted August 10, 2013 Author Posted August 10, 2013 Well here's an update Gave the bike a plugs, oil and filter change. Rear plug looked fine, the front had some fouling. Anyway the bike started easily, he took it a run and came back happy. Two days later I get a call at work telling me the bike had started to run rough, gave a few backfires then broke down, and there was no power in the battery to turn it over. Later on I went to recover the bike, there was just enough juice to start the engine, he rode home and told me that when he used the indicators the bike would cough and splutter. I put a multimeter across the battery and it only showed 10.4v. It wouldn't restart so I couldn't check what it read whilst running. Picked up a new battery today but I'm thinking the reg/rec may be duff. Another thing I noticed was the main fuse (20A) was misshapen as if it had melted at some time Any thoughts on charging system and fuse
neversaydie Posted August 10, 2013 Posted August 10, 2013 Should be charging the battery at 14 to 15 volts at 5000rpm, make sure battery is fully charged first.
bindie Posted August 10, 2013 Posted August 10, 2013 fully charge the battery, check battery is charging when bike is running, (as above should be around 13 - 14v), if this isn't happening possibly reg / rec gone and this in turn could cause damage to the battery if it is charging to high 14.5v + coud be a faulty battery...maybe a dodgy cell
dt502001 Posted August 10, 2013 Posted August 10, 2013 With a melted twisted fuse the reg is either wanting to charge a weak battery and running the charging system at max all the time or the reg has gone open to full charge all the time.Both cases it's real bad for the charge coil to work it so hard will short the life by years if left that way. Best is to load test the battery fully charge with a carbon pile tester and a specific gravity battery tester or refractometer to check each cell,if it passes then check the charging as suggested,most likeyl the reg has failed and killed the battery from over charging it. A lead battery will give off a rotten egg smell when over charging and the battery will start boiling the fluids.If this has happend then you best wash the bike with baking soda to neturalize the acid that are now allover the bike and in the electrical connectors.
jimmy Posted August 11, 2013 Author Posted August 11, 2013 Bought a new battery, charged it up overnight connected up and fired the bike. Gave it a bit of revs (no rev counter, straight through zorsts and Sunday afternoon don't go down well in my bit of quiet suburbia ) and the multi meter was reading 14.8v, so hopefully it was the battery. Looking through the receipts from the PO he bought a battery just over a year ago, but it only cost £16 so I'm thinking cheap shit
dt502001 Posted August 11, 2013 Posted August 11, 2013 14.8 is to high IMO should be dowwn around 13.5 I would consult the manual 1.5 -2 volts over battery voltage is normal @ 2000rpm
jimmy Posted August 11, 2013 Author Posted August 11, 2013 dt The manual says at 5k revs the output should read between 14v and 15v. Once ticking over again the v dropped back down to around 13v
jimmy Posted August 14, 2013 Author Posted August 14, 2013 Righto folks After fitting the new battery on Saturday, the fault has returned, so obviously that was 40brick wasted. The battery is not charging and the bike is starting to misfire and stop running if you try to run the lights so whats next, if it was the rec/reg wouldn't the lights keep blowing (or not?). This maybe leaves the alternator stator...Anything else folks
Moderator DirtyDT Posted August 16, 2013 Moderator Posted August 16, 2013 Back to basics I think. You had a charge when running and before the new battery. It runs rough when more electrical load is put on it. Assuming nothing else has failed, I would be looking for a bad earth, a dodgy connector, a wire earthing randomly or a wire that has broken. All of these will give you intermittent electrical problems and depending if this is the fault can stop the bike from charging the battery or can drain the battery. If a fuse is looking a bit "wrong" then this needs to be investigated. I know fuses are manufactured cheaply nowadays but it sounds like it is getting hot. Only 4 reasons for that:1 it is melting because it is too close to something getting hot when the engine runs2 it is faulty or fractured3 it is getting too much too much power going to it - so the charging system - and overheating4 it is being shorted - wire or connector earthing issue.1 and 2 are easy to diagnose. Assuming the charging volts are ok through the rev range as previously mentioned then 3 shouldn't be the cause unless it is intermittent. A dodgy charging system can cause this but I would eliminate option 4 first because it will be the cheapest to do. That is where I would start. Hook up a multimeter to the battery and monitor the battery volts when you use the switches. Include riding the bike with the multimeter on the tank if you can. See what kind of weirdness you are getting and what you did. Subject to the above not reaping any solutions then it would leave the charging system or reg/rec.There are 5th and 6th options but they involve Alien abduction and the bike being possessed so lets not go there, yet!
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