☆This time I personally need your help....☆
This was a tough decision to decide on. I generally stay behind the scenes keeping this site chugging along. Joe, is the one that gives out the amazing wealth of knowledge he has. I've put an amazing amount of time into the bringing together this website and not to mention have footed the bills a few times. I've kept us hacker free for a damn long time. I never ask much of you guy/gals. Only if we get in crunch time and the site needs a little help. Ive never asked for the ridiculous thousands I have seen another site ask for.. ridiculous is the perfect word. I even removed ads for those that log in, severely cutting revenue. Sites been about helping people, not making money. I feel bad actually doing this.. but I need help. I have gastroparesis brought on from diabetes(20+ years). I've been struggling with this nightmare for over 3 years. Finally diagnosed beginning this year. Look it up. Look up worst cases... that's me. Ive lost 60 lbs since January. 28 days ago the company I've worked for for many years found their dirty lil way to fire me. I was approved for up to 3 days off a week for fmla.. that really pissed them off. So illegally fired, savings drained from medical bills, bad diabetic now with no insurance. I'm in deep shit. That is politely saying it unfortunately. If any of you guys cant help please at least keep me in your thoughts. If this was wrong, me asking for help, my apologies. I'm declining in health fast, and unemployment hasn't came through yet and that in itself is a nightmare. Anyone who can, please donate to the website. This time it goes to help me. Thank you everyone. Again, my apologies for asking. I honestly don't know what to do or where to turn.
Rob *This message can be dismissed by hovering over the upper right corner of it and X should appear. click that.*
UPDATE: THERE HAS ALREADY BEEN A FEW OF YOU DONATING. THANK YOU SO MUCH, I'M LITERALLY IN TEARS AS I TYPE THIS. EVERY PENNY COUNTS. THANK YOU SO MUCH FOR BEING THE HEROES RIGHT NOW.

1986 XV920 front cylinder not running (Netherlands)

Have a question about fixing something on a Yamaha Virago XV920? Post it here!

Moderators: ViragoJoe, choppin

Post Reply
torxnl
Posts: 6
Joined: Sun Feb 20, 2022 2:02 pm
Location: Netherlands
What Virago you Own: 1986 XV920R chain driven model

1986 XV920 front cylinder not running (Netherlands)

Post by torxnl » Wed Aug 03, 2022 6:47 am

Hello,

A few years ago I bought a non running xv920 that had been in a barn for at least 10 years. I managed to rebuild the entire bike lurking on this forum but I'm at a dead end now as the front cylinder will not fire consistently or at all.

What I have done so far to get it in a running state after rebuilding the engine:
  • Installed new plugs
  • cleaned the carbs
  • set the floats
  • bench synced the carbs
  • reset the idle mixture screw.
This got the rear cylinder running just fine. But the front cylinder will not fire at all or sometimes catch on and jump to 2k/3k rpm and then die.
I have checked the following to diagnose:
  • front spark plug is wet after running
  • front plug has spark but seems weaker than rear plug?
  • running on just one cylinder, rear is fine but front jump in rpm then dies or won't run at all.
  • check for vacuum leaks around with starting fluid
  • measured primary and secondary coil resistance, both are in spec
  • cut a small piece of the plug wire to remove corrosion
All of this has lead me to believe that this might be an issue with the TCI since the plug is not sparking as bright as the rear one.

Is my conclusion right? Is there anything else I can do to diagnose?

Hope someone here can help me solve this problem!
Last edited by torxnl on Sat Aug 06, 2022 11:35 am, edited 1 time in total.

User avatar
faffi
Posts: 283
Joined: Wed Jun 08, 2022 9:55 am
Location: Norge
What Virago you Own: 1982 XV750 with XV1100 engine, Seca rear wheel, XT600Z shock, Seca 650 fuel tank

Re: 1982 XV920 front cylinder not running (Netherlands)

Post by faffi » Wed Aug 03, 2022 1:11 pm

Welcom to the forum!

While the TCI may be the culprit, a bad spark plug cap, a bad HT lead, a bad coil and poor power supply (12V) to the coil are all worth checking first. You should, I believe, be able to swap the two coils - after first checking that you have good 12v to both coils - by swapping the 12v connectors between the coils, and then HT leads - just swap the spark plug caps around so that the coils now fire the opposite cylinder.
The journey of a thousand miles begins with a motorcycle.

torxnl
Posts: 6
Joined: Sun Feb 20, 2022 2:02 pm
Location: Netherlands
What Virago you Own: 1986 XV920R chain driven model

Re: 1982 XV920 front cylinder not running (Netherlands)

Post by torxnl » Thu Aug 04, 2022 3:23 am

Thank you!

Good idea to the switch the coils around. I will try your suggestions today after work!

torxnl
Posts: 6
Joined: Sun Feb 20, 2022 2:02 pm
Location: Netherlands
What Virago you Own: 1986 XV920R chain driven model

Re: 1982 XV920 front cylinder not running (Netherlands)

Post by torxnl » Thu Aug 04, 2022 3:01 pm

Okay so I measured the voltage to the coils and both were around 12.3v, so that's good. I then tried swapping around the coils but had no success.

When swapping them back I noticed that the plug wire going into the front coil seemed loose. I hadn't cut off a piece of plug wire at the coils earlier because it seemed very tight and I didn't want to break it. But now I tried to remove it and noticed that the wire was barely touching the contact!

This would explain the weak spark so I removed a small piece from the wire and connected it making sure the wire made good contact with the coil. And of course, I have a good bright spark on the front plug now!

I couldn't immediately get it running on both cylinders but It jumped to 2k/3k rpm shortly after starting the engine, then it dropped down to normal idle again. I assume this might be because my carb settings for the front are off after fidling around with it so much. So I hope it runs better if I reset the carbs to the recommended preset.

I'll give an update once I get to work on it again this weekend!

User avatar
faffi
Posts: 283
Joined: Wed Jun 08, 2022 9:55 am
Location: Norge
What Virago you Own: 1982 XV750 with XV1100 engine, Seca rear wheel, XT600Z shock, Seca 650 fuel tank

Re: 1982 XV920 front cylinder not running (Netherlands)

Post by faffi » Thu Aug 04, 2022 4:55 pm

Sounds promising!
The journey of a thousand miles begins with a motorcycle.

torxnl
Posts: 6
Joined: Sun Feb 20, 2022 2:02 pm
Location: Netherlands
What Virago you Own: 1986 XV920R chain driven model

Re: 1982 XV920 front cylinder not running (Netherlands)

Post by torxnl » Sat Aug 06, 2022 11:29 am

Okay so I tried again today but no luck.

I set the pilot screw to 2 turns out to get started, but I couldn't get it to idle on both cylinders.

When opening the throttle the front cylinder was definitely running but as I let go it would keep surging for a bit and then die.

I checked the spark plug after and it was wet so it is definitely getting fuel so I assume it has to do with the pilot mixture.

What could I try next?

User avatar
faffi
Posts: 283
Joined: Wed Jun 08, 2022 9:55 am
Location: Norge
What Virago you Own: 1982 XV750 with XV1100 engine, Seca rear wheel, XT600Z shock, Seca 650 fuel tank

Re: 1986 XV920 front cylinder not running (Netherlands)

Post by faffi » Sat Aug 06, 2022 12:35 pm

Are you sure one carb is not overflowing or the float height set much too high?
The journey of a thousand miles begins with a motorcycle.

torxnl
Posts: 6
Joined: Sun Feb 20, 2022 2:02 pm
Location: Netherlands
What Virago you Own: 1986 XV920R chain driven model

Re: 1986 XV920 front cylinder not running (Netherlands)

Post by torxnl » Wed Aug 10, 2022 2:06 pm

I tried tweaking the float height this weekend but I can't seem to get it right. The weird thing is they were set correctly.

Last Sunday I got it within spec after taking the carb on and off about 5 times and it would run better but still not consistently on 2 cylinders.

I got to work on it again today and the float height was way too high now. So I guess I should check for a leaking float.

User avatar
faffi
Posts: 283
Joined: Wed Jun 08, 2022 9:55 am
Location: Norge
What Virago you Own: 1982 XV750 with XV1100 engine, Seca rear wheel, XT600Z shock, Seca 650 fuel tank

Re: 1986 XV920 front cylinder not running (Netherlands)

Post by faffi » Wed Aug 10, 2022 5:41 pm

Could be the float, but statistically more likely the needle. That would also explain the variations you have experienced. Could be just dirt, could also be caused by wear. My guess would be dirt, which can be smaller than a naked eye can see.
The journey of a thousand miles begins with a motorcycle.

torxnl
Posts: 6
Joined: Sun Feb 20, 2022 2:02 pm
Location: Netherlands
What Virago you Own: 1986 XV920R chain driven model

Re: 1986 XV920 front cylinder not running (Netherlands)

Post by torxnl » Thu Aug 11, 2022 5:57 am

I'll see what I can find. The float needle is new so I hope it's just dirty!

Post Reply