ViragoTechForum.com :: Yamaha Virago XV Forums That Rock!!!

#1:  Posessed 1984 XV700 (SOLVED) Author: richbark,  Posted: Fri May 14, 2010 10:38 pm Little history: I just completely re-wired the entire bike. Look in the electronics section of the forum to follow that. That was a complete success. I thougt I had only one issue left, tires. Well, surprise another ugly issue has raised its head. Doesn't seem like any that I see on here though. So here goes: Rear cyllinder seems to cut out. If I pull the plug wire and just barely set it on the plug, the cylinder will fire pretty regular. I figured it was a bad plug wire, but I found that the wire cap (a screw in one) wasn't making good contact. I cut the plug wire down an inch and screwed the cap on again. Put new plugs in. Everything was good. Then it came back. Tonight it was awful. I did the usual, pulled the wire and barely set it on the plug and the cylinder was firing ok. I was wondering if I had irregular spark. I pulled the (rear) wire while the bike was running, no real difference in the way it was running. I turned it off and stuffed a new plug in the wire (did not put plug in cylinder - left old plug in there). Started the bike with one plug firing. Watched the new plug - perfect and regular spark (visually). Installed the new plug (old plug -14 days old - was black). Re-installed the plug wire. Bike started and ran perfect. Any ideas what is happening here? I woud like to replace both plug wires, but it seems they are not able to be replaced. it looks like they are permananently mounted to the coils. The most confusing part of all this is how much better the bike ran with the old plug and the wire half off. It ran just as well as it does with the new plug and the wire all on. Anyone have any ideas? I am seriously considering a trip to harley to buy a new 883, and mybe, be able to ride this summer. Last edited by richbark on Sat May 22, 2010 8:48 pm; edited 1 time in total

#2:   Author: Jake,  Posted: Fri May 14, 2010 10:43 pm http://viragotechforum.com/kb.php?mode=article&k=46

#3:   Author: pofarm,  Posted: Fri May 14, 2010 11:21 pm If your plug was black it's most likely fouled out, causing the misfire. The spark is grounding out through the fouling instead of jumping the gap. Sounds like the carb is the problem. It's running too rich. How does the other plug look?

#4:  Re: Posessed 1984 XV700 Author: richbark,  Posted: Sat May 15, 2010 12:51 am The plug from the front cylinder is a nice beige color. I rebuilt the carbs last summer and put the correct jets in for factory pipes, but I am running Jardine slash cuts. Seems like that would lean it out though. I adjusted the main needle valve (the one that is normally hidden under the plug next to the bowl) to 2 and 1/2 turns on each carb. Perhaps I need to adjust the rear in an 1/2 turn. The bike has 13k miles, so not a lot. Compression last summer was at the upper end of the range, so I am not too concerned about wear. I suppose a stuck float might happen though.

#5:  Re: Posessed 1984 XV700 Author: 1986 XV700,  Posted: Sat May 15, 2010 1:34 am The 2-1/2turn out is just a starting point so you are probably correct in turning in the pilot screw on the rear carb. Maybe it needs to be turned in 1/2 turn maybe 1/4 turn will do it. Click HERE for How to Tune Hitachi Carbs. Scroll down to just above the last picture in the first post, it tells you how to adjust the pilot screws. You will want to make these adjustments with the engine warmed up to operating temperature. It will also be a good idea to let a fan blow on the engine to keep it from overheating if it takes several minutes to make the adjustments.

#6:  Re: Posessed 1984 XV700 Author: richbark,  Posted: Sat May 15, 2010 11:39 pm Made an interesting discovery. Started the bike, disconnected rear cylinder plug and adjusted the front carb until bike ran smooth. Re-connected rear cylinder plug, diconnecred the frony plug. Adjusting the main had no affect at all. I am guessing I have some drit or something in there. More interestingly, the bike is running pretty well right now and after a 5 minute ride (after bike was already warmed up), I pulled the plugs. Rear plug is beige, but front plug is dark. So I have to lean out he front a bit.

#7:  Re: Posessed 1984 XV700 - SOLVED Author: richbark,  Posted: Sat May 22, 2010 8:46 pm My bike had a successful excorcism today. I was so frustrated that I yanked the carbs off, took them apart and cleaned everything, re-adjusted the main. Put it all back together (in record time for me). Bike runs awesome! Took it for inspection and rode 50 miles without a hitch. I did not think I would ever see this day! Even got a compliment froma young man at dealer about what a great looking and sounding classic I have - as they were pulling his BRAND NEW STAR out for him! Great Day!!!

#8:   Author: Jake,  Posted: Sat May 22, 2010 9:01 pm That's cool Rich, congratulations. Now, after 4 years as a member, don't you think it's time to attach your signature ? You have it filled out.

#9:  Re: Posessed 1984 XV700 - SOLVED Author: richbark,  Posted: Sat May 22, 2010 9:39 pm I can't figure out how to do it. I did fill it out and I clicked to make it active. It just doesn't show up :)

#10:   Author: pofarm,  Posted: Sun May 23, 2010 3:10 pm At the top of the page, find "Profile." Click on it. On the new page click the "Profile" tab, then click on the "Your Profile" tab. Under "Public Information" click on "Profile Settings." Under "profile Settings" click on "Posting." Here you will find the option to attach your signature. Click "yes."

#11:  Re: Posessed 1984 XV700 (SOLVED) Author: richbark,  Posted: Sun May 23, 2010 9:01 pm Thanks. I followed the directions provided. You guys will let me know if my Signature is working :)

#12:   Author: pofarm,  Posted: Sun May 23, 2010 10:39 pm Yup. It's working now.

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