Forum Donations
Search
VTF Google Search
 Click Here

1986 XV700 Virago Running Issues

  • Advertisement

Post a reply

1986 XV700 Virago Running Issues

PostAuthor: jakob_ohl » Thu May 18, 2017 7:45 pm

Hello all,

I have been fighting an issue with a 1986 XV700 for quite some time now and would greatly appreciate any input.
The issue with this bike is that it begins to break up at around 4,000 RPM's and then clears up but only runs on one cylinder after that point. Before 4,000 it runs perfect. I have replaced almost everything i can think of that would even remotely cause a problem like this. It has had new diaphragms and complete carb rebuild kits on both carbs. I have soaked the carbs in chem-dip as well as used an ultrasonic cleaner on them coupled with a thorough purge with compressed air. I am fairly sure they are completely clean and all passages are clear. I have also isolated all possible vacuum leaks and any air restrictions. I have also tinkered with the fuel adjustment screw under both carbs and have played with different float level settings. All jets and needles have been verified correct in both carbs. I have went as far as taking carbs from another virago that has known good carbs and switching them on to this bike, which resolved its issue. Now i need to get the carbs that are original to the bike to work properly. The odd part is that if i remove the air box form the bike it seems to cure its issue, but with the donor carbs it did exactly the opposite and ran fine with the air box on and terrible without it. I am unsure of what this indicates. I am at my wits end on this one, any input at all would be extremely helpful.

Thanks, Jakob

jakob_ohl
Brand New
Brand New
 
Posts: 3
Joined: Thu May 18, 2017 7:25 pm
  Flag
Bike year & model: 1986 Yamaha XV700 Virago
Sex: Male

Re: 1986 XV700 Virago Running Issues

PostAuthor: drainplug » Fri May 19, 2017 4:26 pm

What do the plugs look like?
Dark/black or white?
That can tell you which way to go, lean or richer.
You might also check the float level to make sure it is within spec.
The wise gardener shakes the tree
User avatar
drainplug
Silver Membership
Silver Membership
 
Posts: 608
Images: 5
Joined: Sat Jan 05, 2013 11:50 pm
Location: Beaver, Utah Flag
Bike year & model: Bikes I still own;
1983 XV920 Midnight
1975 RD125
1993 XV1100
Sex: Male

Re: 1986 XV700 Virago Running Issues

PostAuthor: mark75 » Fri May 19, 2017 5:06 pm

Howdy Jakob. Welcome to VTF.

:yup: check float level with clear plastic tube.
viewtopic.php?f=5&t=55517

also check all your grounds/battery, and clean/tight all connections, esp. to TCI.
an under-fed TCI can mimic many other problems.
The views, opinions, and experiences expressed in this post are mine and may not necessarily represent views and opinions of other VTF members, so feel free to agree, disagree, or ignore them.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

"Over the Mountains of the Moon,
Down the Valley of the Shadow,
Ride, boldly ride" ... E.A. Poe

'13 - FXDC Super Glide Custom
'82 - XV750

Time flies whether you're having fun :yahoo: ... or not ... :fan: BUT --- Any day above ground is a good day.
so Laissez les bon temps roulez ... just roll safely

"I hear and I forget,
I see and I remember,
I do and I understand."
... Confucius*

If you don't read the news you are not informed.
If you read the news you are misinformed. ... Mark Twain
User avatar
mark75
Mod
Mod
 
Posts: 14472
Images: 15
Joined: Sun Apr 02, 2006 3:57 am
Location: Republic of Texas Flag
Sex: Male

Re: 1986 XV700 Virago Running Issues

PostAuthor: bstig60 » Fri May 19, 2017 5:19 pm

That doesn't sound like carbs, that's an ignition problem. Check your plugs as suggested. But I would suggest changing them to Autolite AP63 Platinum plugs and gap them at 0.028 thousands and take another run. If that doesn't solve the problem, it could be a coil breaking down or a bad resistor in the plug cap or a corroded high tension wire..... Let us know what you find.
Bill
"It´s a friggen motorcycle, it´s not supposed to be comfortable, quiet or safe. The wind noise is supposed to hurt your ears, the seat should be hard and riding it should make you s**t your pants every now and then. "

Please take the time to edit your profile to show your location. City, State/Province and Country. It is easier to help you if we know where you are.

SERVICE MANUAL DOWNLOAD LINK
http://viragotechforum.com/viewtopic.php?f=220&t=31501#p279545

Image
User avatar
bstig60
Mod
Mod
 
Posts: 12052
Images: 38
Joined: Sun Jun 08, 2008 6:16 pm
Location: Nevada City, California Flag
Bike year & model: 1999 Yamaha Virago XV1100LC Cruiser
2003 Honda Goldwing GL1800 Touring
Sex: Male

Re: 1986 XV700 Virago Running Issues

PostAuthor: jakob_ohl » Fri May 19, 2017 6:08 pm

The issue that led me away from an electrical problem in the first place is the fact that I put a set of carbs from another Virago in the bike and the problem disappeared. This leads to to believe it is a fuel issue of some sort. It also does have a set of brand new plugs in it. I performed a plug chop and the front cylinder is lean and the rear is rich. I have already played with the float levels to no avail. Again, this one has left me scratching my head. I am running out of ideas. Any further input is greatly appreciated.

Thanks, Jakob

jakob_ohl
Brand New
Brand New
 
Posts: 3
Joined: Thu May 18, 2017 7:25 pm
  Flag
Bike year & model: 1986 Yamaha XV700 Virago
Sex: Male

Re: 1986 XV700 Virago Running Issues

PostAuthor: Jake » Fri May 19, 2017 7:05 pm

Did you clean the screens on the float needle seats ?
Forum Tutorials can be found here http://viragotechforum.com/viewforum.php?f=177

Forward Control Templates ( FREE ) http://viragotechforum.com/viewtopic.php?f=124&t=21556


“It ain’t what you don’t know that gets you in trouble. It’s what you know for sure that just ain’t so.”
~Mark Twain
User avatar
Jake
Mod
Mod
 
Posts: 10864
Images: 111
Joined: Wed Jun 06, 2007 3:18 pm
Location: PA Flag
Bike year & model: 1996 XV750
Sex: Male

Re: 1986 XV700 Virago Running Issues

PostAuthor: jakob_ohl » Sat May 20, 2017 11:45 am

Yes, the carbs have been thoroughly cleaned and rebuilt. I have checked everything in them and all is clean and functional. Any other ideas?

Thanks, Jakob

jakob_ohl
Brand New
Brand New
 
Posts: 3
Joined: Thu May 18, 2017 7:25 pm
  Flag
Bike year & model: 1986 Yamaha XV700 Virago
Sex: Male



Post a reply


  • Advertisement

Return to Yamaha Virago XV700

Who is online

Registered users: Baidu [Spider], Flyingdog, Google [Bot], jamiecafe, Yahoo [Bot]