what does this fit?

[reddevilmedic]

I won this awhile back on fleabay with some other stuff. the unit on the bike I currently run is a 41R-10, this is a 26H-10. when I plug in the 26H, the bike runs like crap, so what is this for?

[ragtop69gs]

I believe that came off an early Model T, it will only work on the 83' if you install the hand crank option and ignition spark retard lever. Available HERE

[Prairiehammer]

The 26H series TCI is for the 1983.

The 41R series TCI is for the 1984-1989

The 3JJ series TCI is for the 1990-1993

 

The 41R shouldn't work well on your 1983, unless you have changed the vacuum pick-up point from the stock carb location. Maybe you have a 1983½? What is your VIN?

[reddevilmedic]

vin JYA31M003DA002547. I havnt changed any vacuum stuff.

[reddevilmedic]

when I plug in the 26H, the bike will idle correctly for about 10 seconds, then rpms drop to about 400 for about 5 seconds, then back to norm for 10 secs. it just keeps doing that pattern, back and forth.

[dingy]

The 26H series TCI is for the 1983.

The 41R series TCI is for the 1984-1989

The 3JJ series TCI is for the 1990-1993

 

The 41R shouldn't work well on your 1983, unless you have changed the vacuum pick-up point from the stock carb location. Maybe you have a 1983½? What is your VIN?

Look at your left carb pair and see if there is a vacuum port on the #2 carb (see picture, red plug). If there is a port there, then this is an 83 set of carbs. No port and carbs are from 84-93, could be 34mm or 35mm though.

 

The 26H TCI must have the vacuum hose attached to this port, 41R & 3JJ (and Ignitech) must have vacuum hose attached to intake boot port.

 

Difference is the vacuum profile is opposite between the two ports, on the 83, it is above the butterflies, so it sees an opposite curve as compared to port on intake manifold. This difference causes Boost sensor to send inaccurate signal to TCI when wrong port is used. This then tells TCI to retard timing when motor needs it advanced.

 

You can use a 84-89 TCI on an 83 bike if you plug the carb port & move vacuum line to intake boot. 83 TCI can only be used on an 83 set of carbs unless port is added to newer set of carbs.

 

Gary

[frankd]

Unless you've owned the bike since it's been new, there is always the possibility that one of the previous owners changed the TCI to a 41R and re-piped the vacuum advance.

[reddevilmedic]

there is a port and a hose attached to it.

[reddevilmedic]

and the hose is plugged into something just above the yics box..

[dingy]

there is a port and a hose attached to it.

 

Is there a hose going to any of the four intake manifold ports?

 

If not, I would try swapping vacuum line to an intake port and see what the 41R runs like. Auto Zone sells caps that will fit the port on carb that hose is removed from, you can't leave it open.

 

Gary

[dingy]

and the hose is plugged into something just above the yics box..

 

That's the boost sensor, it will also have a 3 conductor plug going into it.

 

Swap vacuum line per last post and see if it runs any better. It should.

 

The 26H unit could be damaged.

 

Gary

[reddevilmedic]

there are no lines going to carb boots. so you want me to run a hose from the boost sensor to the carb joint? and plug the carb port?

[reddevilmedic]

the 41R runs pretty good with the hose from the boost attached to a carb joint. the 26h runs like crap no matter what I do. next question, how do I sync the carbs with the boost attached to a carb joint?

[dingy]

the 41R runs pretty good with the hose from the boost attached to a carb joint. the 26h runs like crap no matter what I do. next question, how do I sync the carbs with the boost attached to a carb joint?

 

Sync is done with all four carb boots plugged into manometer (carbtune). I don't think the boost sensor has any effect at idle. It will be unplugged, no need to cap the vacuum tube during sync.

 

Gary

[dingy]

there are no lines going to carb boots. so you want me to run a hose from the boost sensor to the carb joint? and plug the carb port?

 

Yes. This is using 41R unit.

 

Gary

[reddevilmedic]

ok. did the boost reroute to carb joint. then decided to adjust idle to 1000 (it was low) and sync carbs using carb tune. carbtune needles were a bit jumpy, but, got it real close. seems to be running better. why do the needle on carbtune flutter? should they be steady?

[dingy]

ok. did the boost reroute to carb joint. then decided to adjust idle to 1000 (it was low) and sync carbs using carb tune. carbtune needles were a bit jumpy, but, got it real close. seems to be running better. why do the needle on carbtune flutter? should they be steady?

 

Do you have the restriction tubes in the carbtune vacuum lines? That will help smooth them out.

 

You should see a difference in performance when riding it now.

 

Gary

[reddevilmedic]

just gassed it up, runs a lot better! thanks for all your help. I don't think I have the restriction tubes....

[Prairiehammer]

carbtune needles were a bit jumpy, why do the needle on carbtune flutter? should they be steady?

 

If you have needles, you must be using dial type gauges. The Carbtune® uses steel bars to ride up and down in clear tubes. Dial guages should also have some restrictors, but will still be pretty jumpy as compared to the genuine Carbtune®.

[reddevilmedic]

I meant steel bars...I didn't know what to call them. its a carbtune pro

[dingy]

I meant steel bars...I didn't know what to call them. its a carbtune pro

 

Just on the extremely remote possibility that a man hasn't read the instruction manual for the carbtune, I attached a couple of pictures.

 

Gary

[reddevilmedic]

oh those.....