Question about an 85 vr

[Guest mrutah12]

Good afternoon all just singed up to today Have a question to ask i have a buddy who has an 85 vr and he has a problem we are trying to figure out when the tach drops below i think hesaid around 2500rpm i am not 100% on the rpm s but he drops a cylinder and loses the tack above 300 rpm everthing runs great crusies prefect until you start to drop speed or come to a stop thn the tach quites and he loses a cylinder then bring the rpms back and preston you have all four cylinders again. any suggestion's on what to look for.

[Venturous Randy]

TCI going out?

RandyA

[Dano]

Use a digital voltmeter set on DC volts, check voltage at the battery at idle, then at 2500-3000 rpm's. These bikes do not develop full voltage from the stator till 2500 rpms. Bike will run like crap till it gets full voltage. Also, pull the left side cover, right under the seat at the rear of the opening you will see a white plug with 3 white wires going in to it. Pull it apart and check the connections. This is the feed from the stator to the regulator. They have a history of burning up. Cut the connector out, buttsplice and heat shrink these wires to remove any future problems. You might need a new battery, too.

 

Try these out and let us know whats going on and we'll help the best we can!

 

Dan

[Rocket]

Also check all the connections for #2 coil (front left under the battery box), as the tach gets its signal from there. You could have poor / dirty contacts there or at the TCI plug ins. It is best to check connectors for all of the coils, while in there.

 

[painterman67]

Haveing the same prob on my 91, Find yourself a new tci/cdi/ignitor assembly. All different names for the same thing.

 

 

Good luck. There are a few on ebay butnot sure of the years. Be specific as on certain ones will work with other bikes. As I undertad it 83- 85 same part #, 86-89 same part #, and 90-93 same nuber on the first gens.

 

David

[GeorgeS]

Ditto, on the above items. ---

 

Also:

 

Get a can of CRC ( brand name ) 2-26, electrical contact cleaner.

 

Give the Ignition Switch a Bath.

 

Give the RUN-STOP Switch a Bath. ( blow out both with compressed air )

 

Remove the TWO plugs from the TCI. ( under air cleaner box ) and clean the pins on both plugs with the CRC stuff.

 

Also, Inspect the " Ignition Fuse " in main fuse block, the tang that hold the fuse in place, might be loose, or ready to break off. Polish the holder clips.

Also, replace the 15 Amp fuse there, ( slight possiblity, very slight, that the fuse is going bad )

 

All 4 plug wires, Screw them out of the plug caps, and Ignition coils, and NIP OFF about 1/4 inch of the plug wire, and re-install. ( the wire, screws in and out ) ( it does, trust me )

 

Run 1/2 Can of SEA-FOAM, with 1/2 tank of Gas.

 

Drain all 4 Carb bowls, Each has a seperate Drain hose. #2 phillips, to open the Drain lines.

 

Remove the Hose from Petcock, and Completly DRAIN, the Fuel tank !!!!

Edited February 7, 2009 by GeorgeS

[bobcat]

I agree with Randy.....TCI

[Yammer Dan]

I agree TCI issue but check the connections on it before giving up on it and maybe pull and Dry.

[rhncue]

Haveing the same prob on my 91, Find yourself a new tci/cdi/ignitor assembly. All different names for the same thing.

 

 

Good luck. There are a few on ebay butnot sure of the years. Be specific as on certain ones will work with other bikes. As I undertad it 83- 85 same part #, 86-89 same part #, and 90-93 same nuber on the first gens.

 

David

 

I'm afraid this is wrong data. 83 is by itself and none other will work correctly on it, 84 through 89 are the same and 90 through 93 are the same. Yamaha kept making improvements through the years so the 89 would be the best to get a hold of if possible for an 84 - 89.

 

Dick

[woz111]

I agree that it may be the TCI unit starting to fail, if your good with a soldering iron repair it, its not too difficult, if your not I can repair them so's long as the PCB's not damaged, so email me?

Edited February 7, 2009 by woz111

[GeorgeS]

Might be moisture in the TCI Unit. Remove the unit, remove the cover, and dry it in an oven at about 110 deg. F for a couple hours.

 

Then resolder the Two Plug, where the connect to the Circuit Board. Should be 14 connection points. They develop Cold solder joints, ( ie. high resistance ) or even cracks, in the original soldering at the connect points.

[Dano]

I would still start with the easiest stuff first, check battery and voltage output from the regulator/stator.

[painterman67]

I'm afraid this is wrong data. 83 is by itself and none other will work correctly on it, 84 through 89 are the same and 90 through 93 are the same. Yamaha kept making improvements through the years so the 89 would be the best to get a hold of if possible for an 84 - 89.

 

Dick

 

Ok, I wasn't sure of the years except 90-91. That being said, I have what was writin as a tci box off of a 88. If this will work let me know and I'll ship it to you. I paid $ 53 for it on ebay. Will ship it to you for that price. If it works and you want it you can pay me after you find out. If not ship it back to me . Only reson I say this is tha originaly i was told 85 -93 all the same and I bought this one on ebay . The seller sadi it came of a functioning bike. I would hate to sell you something that doesn't work as I cant test it on my bike.Pm me if you are interested or you can call me. My number is in the vr assistance and I think aqlso on my profile.

 

Hope this will help you or any others reading this as it is dooing me no good. Not trying to make anything but my money back. Good luck.

 

David