reachn' out for help

i have a 1981 xv920 with troubles it starts up and idles fine but when given the throttle it falls on its face and dies. if anyone can help i would be greatful

sounds like a carb issue,,,you should do a good clean up on the carbs and also spark plugs too

Sounds like a card issue. Sticking float needle or split diaphragm's?

nice looking bike :thumbup:

I agree that it is a carb problem, also could be a clogged intake if the bike has sit for a while. check for obstructions in the airbox

It means she's either starved for air or fuel. The easy one is to check the air path all the way to the carbs. Then, drop the carbs and give them a good cleaning. Check to see that the floats actually do float. Check the needles as Nelly pointed out. Remove the jets and be sure nothing is obstructing them.

Then throw in some good fresh plugs.

Last is the gas tank. Sometimes a foreign object can get into the tank that may not clog the outlet enough to stall the bike, but when you start a higher demand on the flow (twisting the throttle), that little bugger will stop up the fuel flow. When it stalls, the piece will float free. Start it up and the whole process starts all over... Take the tank off and dump it into a pail. Flush it out with more fuel into the pail. If the petc0ck is removable, take it off and check for clogs. Filter the fuel into another container with the finest filter possible then put it back in the tank.

Let us know how this turns out cause that's a COOL bike!! Good luck!

Check the inlet manifolds between the carbs and the cylinder heads. Unless they have been replaced within the last 10-15 years they WILL leak air. Just spray them with WD40 as the motor idles, if the revs change you have found at least one problem. Getting replacements might be a bit of a challenge but not impossible, there is a lot of NOS still out there for 20-30 yr old Japanese bikes.

Assuming it's a CV carb, the slides aren't lifting. They might be stuck, or the diaphrams might be torn.

Heck, just tear the carbs apart and rebuild them. You'll be glad you did.

I agree that carbs are most likely culprit but don't forget to check battery as well. They don't last forever and it's easy to check for fluid levels and voltage. Amperage might mean removal and a trip to an auto-parts store but still not hard and usually they do check for free. I'd do the easy stuff first then move on to carbs if needed. I had similar problems on a Ninja and it turned out I apparently had spark blowout from weak battery. Still betting on carbs though...

And I'd advise you to not put the gas back in bike if it's the least bit suspect. Use it in your lawn mower, they're a lot more tolerant of funky gas.

mdr said:

And I'd advise you to not put the gas back in bike if it's the least bit suspect. Use it in your lawn mower, they're a lot more tolerant of funky gas.

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I was assuming it wasn't funky gas, just a foreign object in it. This actually happened with a used car my son bought. Drove off with it but when he got to 1/4 tank of fuel, it quit. Started back up, ran a couple minutes and quit.... long story short, the garage pulled the tank and drained it. Out came a short piece of rope! It was clogging the fuel pickup. All better now.

FZ6inNH said:

I was assuming it wasn't funky gas, just a foreign object in it. This actually happened with a used car my son bought. Drove off with it but when he got to 1/4 tank of fuel, it quit. Started back up, ran a couple minutes and quit.... long story short, the garage pulled the tank and drained it. Out came a short piece of rope! It was clogging the fuel pickup. All better now.

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Roger that. Poster didn't mention how old gas was. Some folks (not me) have suggested that gas goes bad in as little as two or three months. I was just being paranoid

Nelly said:

Sounds like a card issue. Sticking float needle or split diaphragm's?

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i already draind' the gas tank, and i have two pet****s on each side of the tank, and they have diaphragms on the back of them, but gas does flow good out of them. sprayd' wd40 on the inlets and no change. it has mikuni/hitachi carbs. not sure which thats what they came out with anyways.air to carbs are clear.i could have the wrong battery on it,but not sure if that made a diff. i did have one person tell me that it could of jump time. but the carbs sounds more like the trouble im haven'. as you all can tell i dont know much about bikes

ok. Another quickie thing to check. Clogged air filter? Probably not but...

Nice bike (love the older ones) but how bout a little more history on it. How long have you had it? Did it work before and you stored it and now it doesn't? or - you bought it recently from someone who said it "Runs fine" only you didn't really check until now and found it didn't or ... what? When was the last time it ran ok?

How long did you idle it before starting to give it gas? Some bikes are cold natured and take a few minutes to warm up. My Suzuki GS500F takes about 2 minutes before it's ready to ride and then I have to leave it partly choked for the first mile or two. Are you leaving the "choke" on when giving it gas? What's the idle speed in RPM? Have you owned other bikes to compare this one with?

xv920 said:

i already draind' the gas tank, and i have two pet****s on each side of the tank, and they have diaphragms on the back of them, but gas does flow good out of them. sprayd' wd40 on the inlets and no change. it has mikuni/hitachi carbs. not sure which thats what they came out with anyways.air to carbs are clear.i could have the wrong battery on it,but not sure if that made a diff. i did have one person tell me that it could of jump time. but the carbs sounds more like the trouble im haven'. as you all can tell i dont know much about bikes

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yea well you should take the carbs out,,unscrew the screws that holds the bottom pan of the carbs,,,floater is there,,make sure its loose,,,you have to remove the floater to reach the jet,,you gotta unscrew that and make sure its clear,,,and also there is a screw on the side of the carb that adjusts the air ratio,,you shouldnt touch it but it might be out of tune,,,,also because there are 2 carbs,they could be out of sync and that could be causing that also.....if you are not capable of taking care of the carb work ,i would suggest taking it to a shop to take care of them,,im sure when the carbs are all tuned up,the bike will run just fine

Sounds like it needs air. Check the air filter and intake. Try removing the air filter and start it. It could also be a choke problem. Start the bike and let it warm up before you give it some throttle and see if it reacts differently than when its cold.

a little more history on it.



i only had the bike for a couple weeks now, i got it on a really good deal, the bike was trader to the harley dealer, the sales man took it on trade, but wasnt surpose to so he had to take the bike or lose his job, (i know this cuz i know another guy that works there) any ways i like bikes i want to ride got this one cheap really cheap, when i got the bike all they could tell me is that a kid knock it over and its been doing this ever since, starts up fine but when you roll the throttle it dies.

i took the carbs off my brothers bike which is a 82 xv920 virago (same motor) that didnt change anything still does the same ol' thing i did drain the gas put new gas in havent tried the new plugs yet, new air filter. but i have seen an air bubble in the gas line. i have two pet****s on each side of the tank. one with the gas is on with no line on it the gas doesnt come out, but the other one gas comes out of it would that cause an issue. i work on cars a long time. the bike thing is a little diff,

I had a similar problem on my old 1982 Maxim
check for:
- intake manifold leak (cracks around intakes or loose connections)
- air filter
- spark plugs
- ignition coils/ignition pick-up (if the kid knocked it over, something could have disturbed the ignition pick-up)
- carb/fuel problem (for me this was the problem, but since you swapped carbs and changed the gas, maybe the problem isn't here...)

About your petc0ck situation, i think one of the outlets is actually a vacuum line that relies on the intake vacuum to open the petc0ck to allow fuel to flow. I really don't know much about Virago's, but the Maxim's had a vacuum operated petc0ck.

And another ting, like mdr has said, are you using the choke?

using the choke?



the choke not making any diff. as soon as i use the choke it dies. the pet****'s have a fuel out out and a vacuum line going in on both sides

Are both carbs getting fuel? Follow each inlet from the carb bowl back up to the tank. Try each petc0ck to be sure both carbs are being supplied the same amount of fuel. Check the remaining two lines to see if there is any blockage. If it idles, it's getting a minimal amount of fuel but not enough to feed the carb bowls when you give it throttle.

Try what rvbiker states... take the air out of the equation and run it without the air filter or remove the snorkels from the carbs directly. Run it and try the throttle. If it still dies, you're starved for fuel and can focus on that.

Have you tried this forum? ViragoTechForum.com :: View Forum - XV920

Good thread to start in: http://viragotechforum.com/phpBB/viewtopic.php?t=10001