'83 tci

[koonta]

Is an '83 TCI box the only box you can use on an '83 VR? Without going to an after-market.

[bongobobny]

Unfortunately yes. It has to do with where the vacuum comes from, 180 deg out of phase with the '84 to 89...

[dingy]

You can use an 84-89 box on an 83.

 

You can not use an 90-93 unit.

 

However, due to the 84-89 bikes not having the carbs drilled for the vacuum line, you can not use an 83 TCI on 84-89 bikes without drilling for the vacuum port.

 

To use the 84-89 TCI on an 83 bike you need to block the port on the carb bank where the vacuum line hooks to.

 

Then the line will be reattached below the carbs to the rubber intake manifold.

 

On the 84-89's there is a plastic restrictor to help smooth out the pulsing in the vacuum. It is not a valve, just a plastic tube with a small hole inside. It also serves to connect the two different size vacuum lines together.

 

I am currently running an 86 TCI on my bike, but also have the original 83 TCI that I have also ran on it. It runs just as well with either unit.

 

Gary

[koonta]

Thanks, guys, at least I have a few more options searching for another TCI.

[bongobobny]

Leave it to Gary to reverse engineer the TCI to make it work on the '83!! I was not aware of this but it makes sense! It's just not quite plug and play...

[koonta]

Found a salvage yard here in Mi. with 2 boxes, I rode over today and the first one I tried was off another '83, no good, 2nd was off an '84, miss was gone, rerouted vacuum lines and rode home.

THANKS, for all the help here!

[timgray]

EDIT to remove bad information from me not reading right.....

OOPS! I did not read correctly... too many smacks to the head or it might be effects of joining the over the bars club when I was younger...

 

I strongly suggest looking at the aftermarket ingitech. I trust it being new compared to a used unit that will fail on the road like mine. The diodes in the Stock Yamaha TCI's are defective and will self destruct from age. My original TCI was perfect inside except for the diodes disintegrated. when they fail they also take out other parts of the TCI so that repair is no longer possible.

 

I also spent a lot of money buying TCI units used off ebay only to spend the same money for the ingitech in dead TCI units.

Edited July 8, 2010 by timgray

[dingy]

Incorrect. simply hook the vac sensor line to the same place the 84+ has it. That's how I have my aftermarket hooked up. cap off the 83 port location and hook it to the VAC sync port on the #2 carb. No drilling needed at all.

 

I strongly suggest looking at the aftermarket ingitech. I trust it being new compared to a used unit that will fail on the road like mine. The diodes in the TCI's are defective and will self destruct from age. My original TCI was perfect inside except for the diodes disintegrated. when they fail they also take out other parts of the TCI so that repair is no longer possible.

 

I also spent a lot of money buying TCI units used off ebay only to spend the same money for the ingitech in dead TCI units.

 

Tim,

 

You are comparing apples to oranges.

 

The TCI you are using is a programmable model, that possibly could be used above or below the throttle plates, with the right curve put in it.

 

If the TCI is from a 1983 vintage,(26H serial number prefix) it must have its vacuum sensor connection above the throttle plates. Needs dual pick-up coils.

 

If the TCI is from a 1984-1989 vintage,(41R serial number prefix) it must have its vacuum sensor connection below the throttle plates. Needs dual pick-up coils.

 

If the TCI is from a 1990-1993 vintage,(3JJ serial number prefix) it must have its vacuum sensor connection below the throttle plates. Needs single pick-up coil.

 

The pressure sensor part numbers are the same for 1983-1993.

 

What I meant by the drilling statement was that an 83 TCI could be made to work on an engine that did not have a set of 1983 carbs on it. This could be done by drilling a port in the #2 carb body & fabricating a hose connection. It is unlikely that this would be done, but it is possible. The casting boss is present on the carb where the port was drilled on the 83 version. To use the 84-89 TCI on an engine with 83 carbs on it, simply plug the port above the throttle plate on the #2 carb and hook vacuum sensor to rubber intake boot below carbs.

 

Internally, there is no appreciable difference as far as the timing of the engine, from 1983-1989.

 

Gary

[timgray]

I must have mis-read your post. My point was that an 84+ TCI pulls the Vac from the same side of the carb you test for Carb sync, below the throttle plates. So there is no reason to drill a hole on a 83 bike to install a 84+TCI.

 

 

So installing a 84-89 TCI on a 83 bike needs no holes drilled, just use the carb sync port and cap off the old 83 vac sensor port.

 

But using a 83 TCI on a 84-89 bike needs a hole drilled and a port added.