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Intermittant single cylinder

Started by Neil, August 23, 2013, 10:23:05 PM

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Neil

My wife's '82 had one cylinder and the tach cutting out intermittantly. It will run fine, then lose one cylinder and the tach function, then after a couple of minutes or less both come back and function properly. Anyone else recognize these symproms and know the cure?

Craig B

Yep been there. My problem ended up being a dodgy spark plug lead/ loose connection? Went over whole bike with CRC to all the electrical earths too frame as well.

Rick G

The rev limiter is faulty . it thinks that the engine is always over  12000 rpm .. cut or unplug the limiter wire at the TCI box  and the problem will go away.
Rick G
Go soothingly on the grease mud, as there in lurks the skid demon
'82.5 Yamaha XZ550 RJ  Vision,
'90 Suzuki VX800, 1990 Suzuki DR350.
'74  XL350   Honda , 77 XL350 Honda, 78 XL350 Honda, '82 XT 200 Yamaha, '67 Yamaha YG1TK, 80cc trail bike

Neil

Rick, I see nothing showing a rev limiter in the 82 or 83 factory wiring diagrams. There is a yellow/black wire from the black box to the tach. Others have suggested disconnecting that wire. Is that what you mean, too?

Neil

Quote from: Craig B on August 23, 2013, 11:07:28 PM
Yep been there. My problem ended up being a dodgy spark plug lead/ loose connection? Went over whole bike with CRC to all the electrical earths too frame as well.

Thanks, Craig. Good things to check.

jefferson

Rick was talking about the yellow and black wire. Pull the plug off the ignition box and remove that pin and wire from the plug. With a real small screwdriver or a pick you should be able to release the clip that holds it in the plug. You should be good to go then.

Jeff

Rick G

Thanks for the clarification Jeff . Yes its the  Yellow and black wire. The tach sends the rpm info to the TCI  and it   interupts the  signal at 12000 rpm. Except when the board in the tach thinks its always over 12000 and makes it miss.
Rick G
Go soothingly on the grease mud, as there in lurks the skid demon
'82.5 Yamaha XZ550 RJ  Vision,
'90 Suzuki VX800, 1990 Suzuki DR350.
'74  XL350   Honda , 77 XL350 Honda, 78 XL350 Honda, '82 XT 200 Yamaha, '67 Yamaha YG1TK, 80cc trail bike

Jimustanguitar

If you don't like the idea of cutting the yellow/black wire, it connects to a screw on the back of the gauge cluster. You can remove the screw and tape up the wiring eyelet there instead. Both will yield the same results.

Neil

Thanks, guys. This is a great help. Yesterday, we went for a ride. Her Vision started on one cylinder, then ran fine for the whole morning ride, about 80 miles. I think I'll install a bullet connection on the yellow/black so the next time it misbehaves I can easily disconnect it. Of course, she never runs it up near red line, so disconnecting it doesn't really have a disadvantage.

Ironically, I have a Honda NS400R that is doing the same thing. Go figure!

jefferson

I bet you are running on 2 on that one. Just cutting one cyl, Right?

Jeff

Neil

Jeff, When it does it, the NS 400 will run on just one cylinder, the middle one. The ignition system has two ignition boxes and two ignition pick ups. The two front cylinders that are cutting out connect to different boxes and pick ups.

Neil

Hey Guys - This is really weird now.

Yesterday I installed a bullet connection in the yellow/black wire just above the multi pin connector at the Igniter box. Although the bike ran fine Sunday and started right up yesterday, I wanted to be able to disconnect the yellow/black to the rev limiter if it happened to my wife again out on the road somewhere.

I also looked inside the Igniter box with a magnifier and didn't see anything obviously wrong. Before reconnecting the two multi pin connectors, I made sure they were clean and put some dielectric grease into the connectors. Now, here's the weird part - installling the smaller multi pin connector (red, brown, black wires) caused the bikes electrical system to energize with the key off, except for the tail light and license plate light. All other lights went on, the signals worked, and the horn worked. Turning the key on made the tail light and license plate light work. On top of that there is no spark and it won't start, with the key in the off or in the on position.

This condition didn't change after a thourough cleaning and removal of the dielectric grease from the Igniter's two multi pin connectors. It also didn't change after overnight prayers, and morning attempts to find the right combination of curse words!

Anyone have suggestions on this weirdness?

QBS

#12
Not sure, but seem to remember that there are two connectors that live in that area.  One is related to the REG/REC and the other is for the TCI box.  Sometimes people mistakenly connect them wrong way around with deadly results for the TCI box.  Check this out before your try to start the engine again.

Rick G

#13
I would never mind the bullet connector. disconnect the damd thing and be done with it ! It serves no useful purpose , if you use the tach . I cut mine 10 years ago and have suffered no problem as a result. You have misswired something . I hope you didn't toast the TCI! You really have to try to  run the Vision up against the rev limiter.
Rick G
Go soothingly on the grease mud, as there in lurks the skid demon
'82.5 Yamaha XZ550 RJ  Vision,
'90 Suzuki VX800, 1990 Suzuki DR350.
'74  XL350   Honda , 77 XL350 Honda, 78 XL350 Honda, '82 XT 200 Yamaha, '67 Yamaha YG1TK, 80cc trail bike

Rikugun

#14
QBS gets the prize  :)  You connected the 4 position harness plug meant for the Regulator/Rectifier into the TCI.

Connecting that plug to the TCI made a connection between Red (12+) and Brown (system power) in the wiring harness similar to what the key switch does when turned to "ON". The plug that's supposed to go in the TCI has the pickup coil leads which is why it wouldn't start. The reason you got no tail light is that connection (with separate contacts) is handled through the key switch with it's own fuse. This separation in the key switch also allows the tail light to illuminate with the key removed from the switch "Park" position.

Connect the plug with red, brown, and black into the lead coming from the R/R and the plug with the White, Red, and Black ('82) into the TCI. Then cross your fingers and hope for the best.  ;)
It is far better to grasp the universe as it really is then to persist in delusion, however satisfying or reassuring.  Carl Sagan

Neil

QBS & Rikugun - Thanks for the thoughts and possibility but it's not a mis-connected connector and definitely not the regulator/rectifier connector connected to the Igniter. I checked and confirmed that the two Igniter box connectors are the ones that I connected to it. I also got another Igniter box and tried it with no improvement  :(  I had hoped that would solve the puzzle.

The Prophet of Doom

The brown wire is positive switched, red is positive unswitched
My guess your R/R has died, and is bridging the two.  That would light up your bike with the key off.
Tail and plate lights work off a different circuit than other switched items.  Blue wire rather than brown.
That doesn't explain no spark, but perhaps high resistance in your failed R/R is causing voltage drop.

Rikugun

Quote from: Neil on August 30, 2013, 02:39:48 PM
Now, here's the weird part - installling the smaller multi pin connector (red, brown, black wires) caused the bikes electrical system to energize with the key off.......

My bad, I assumed you plugged this into the TCI, not the R/R.  :-\
It is far better to grasp the universe as it really is then to persist in delusion, however satisfying or reassuring.  Carl Sagan

tig5

In my limited but growing experience, a faulty or temperomental R/R will cause you to lose a cylinder. My bike runs fine for about 10 mins after the battery is fully charged then starts to fail. R/R seems to be the culprit. I've never experienced the electrical issues you have but at a guess, I'd say these symptoms depend on if the R/R fails while in the "open" or "closed" position.

The Prophet of Doom

Quote from: Rikugun on September 04, 2013, 07:29:41 AM
My bad, I assumed you plugged this into the TCI, not the R/R.  :-\
No, you are right Rik, as usual, what threw me was the bit about the wire colours.  The smaller connector is the lines from the flywheel triggers.  They aren't red, brown, black wires on my bike, but black, black, red, white.

I take back what I said
Dunno - Dead short in the pickups perhaps? they are supposed to be 110 ohms