tci box

[motorhead704]

hello still having idling problem I went down the list of things to check. I resoldered the pins on the tci, removed the stop switch and cleaned it. took all the conectors aprt and cleaned them, changed the plug wires and plugs but it still want idle.It starts and runs when the choke is on,but when it warms up and the choke shuts off and it starts to idle the tack drops to 0 and it starts to back fire thru the tail pipe it will idle but is very low all most the point where it shuts off. on the road it runs good but when you let off to stop the tack will drop and it starts the backfiring. when I am idling it seems to be loading up bad you get a lot of fumes from the tail pipe. Is there some way to check the tci box to see if it is bad.I would like to try that before I take it to the shop. around here its so costly they want your right arm and your first born. thanks alot Darrell

[koonta]

can you throttle up a bit to keep it running, when does it smooth out?

[Monty]

Clogged jets in the idle circuit? Did you try the Sea-Foam treatment? Did you drain the bowls?

[motorhead704]

it will smooth out at about 1500 rpms and run good but when you let off it will hold the 1000 rpm idle for a few seconds and then the tack will drop to 0 and it starts back firing. I ran some seafoam thru it but I did not drain the bouls yet because i did not know where to drain them. thanks Darrell

[GeorgeS]

Have you done the following items.

 

1. Drain all 4 Carb Bowls, with Sea Foam added to the gas, ( Each carb seperatly, and turn key to ON so fuel pump will force gas thru each carb bowl seperatly )

Make sure all 4 have about equal flow.

 

2. Completly drain the gas tank if you have not done so, that bottom gallon has been sitting in there a long time .

 

3. Have you replaced the Fuel filter ???

 

4. I would pull the 4 Plugs, and mark which cylinder each came from. How do the plugs look??? I you have digital camera, post photo of the plugs.

 

5. Remove the Air Filter, and with hot engine, run, and watch the Pistons in all 4 carbs " Danceing back and Forth " The Motion on all 4 should be the same,

--- If one or more is not danceing, then pull the cover off that Carb, and Inspect the Rubber Diaphram.

 

---- Beginning to sound like you may need a new set of diaphrams.

 

6. RED--- RUN,STOP SWITCH--- Folow the cable from that switch to up under the headlight, to a pull apart plug. Open the plug, and take a Resistance reading Thru the "Run-Stop" Switch. ---- IT MUST READ ZERO OHMS, Any resistance across that Switch, will " lower " the operating voltage to the TCI.

 

7. You "might" Just need a carb Sync Proceedure done on your bike.

Pull up the Service Manual, its on line this web site, in Maintenance section. Read up on the proceedure, if you have never done it before.

 

Take a look at the Throttle PULL cable at the left fwd Carb. Check to see if the Pull cable has about 1/16 to 1/8 inch of free play before the mechanicanal linkage starts to move when you add throttle. IF not, it pretty sure you need to sync the carbs.

 

8. With Engine COLD. do the Hot Pipe feel test. Start engine and run for about 60 Seconds, and shut down, then feel each Exhaust Header, Make sure ALL 4 are about the same temp. IF one is Cold, then you know which cylinder has the problem.

 

9. Have you checked for " Intake Air Leaks, Above, and below each Carb, and also check the 2 bolts on each Intake manifold, where mounts to the Cylinder Head.

Leaks, at the cylinder head are fairly common.

Be sure to Check those big Clamps above and below each Carb!!

 

10. Be Sure that All the Hoses's UNDER the AIR Box, are in place and hooked up.

11. Make sure the caps on all 4 Vaccume ports are Sealing tight !!!

 

12. From the Left Fwd Carb, follow the vaccume lines, from the vaccume port, up to the "Barometric Pressure Sensor " Its located Fwd, and Above the left Fwd Carb. The hose Might be loose from the Sensor.

Also this hose has a "" Tee Fitting "" about half way, and the line off the TEE goes to a port, under, front, center, of the Air Filter Box. MAKE SURE ITS IN PLACE AND NOT LEAKING.

 

13. When you get to the Barrometric Sensor, Pull OFF the Rubber Boot covering the Electrical Plug on the Sensor, I know of at least one 1st Gen, that quit running because there was water, and crud, and stuff, growing in the boot, causeing a High Resistance Connection Across the 3 Pins. THIS WILL ALSO LOWER THE VOLTAGE GOING TO THE TCI !!!!-----NOT GOOD, NOT GOOD.

 

I list all the above, in no particular order, a witch hunt so to speak !!!

[dingy]

12. From the Left Fwd Carb, follow the vaccume lines, from the vaccume port, up to the "Barometric Pressure Sensor " Its located Fwd, and Above the left Fwd Carb. The hose Might be loose from the Sensor.

Also this hose has a "" Tee Fitting "" about half way, and the line off the TEE goes to a port, under, front, center, of the Air Filter Box. MAKE SURE ITS IN PLACE AND NOT LEAKING.

 

 

I do not believe there is a 'tee' fitting in the vacuum line to the pressure sensor from the #2 carb. There is a plastic reducer fitting that serves to even the pulsing of the vacuum out.

 

It would help us to help you if you did not start a new thread each time when you are seeking help for the same problem. This is the fourth thread on this problem from you. It would keep all the responses in one thread, so we can see what has been suggested for you to try. That's up to you, of course, but if we get feedback from things that have been suggested, and you have tried, it might lead to other areas. The thread will get pushed to the top of the history stack with each new post.

 

Gary

[GeorgeS]

On most of the 1st gens, the line from that carbs vaccume port, does go up to the Barro Sensor. and has a T, which goes to a port under the front, bottom of the Air cleaner box.

At least my 89 does.

 

Its possible that its been removed on some of the 1st gens. However that would take out the Barro Sensor, and the Timeing advance function. But most folks would not even notice if the barro sensor was not working.

[bald josh]

if at idle the tach drops to zero then i would think no spark to at least #2 cylinder.that combined with say, poorly synced carbs might be the problem.

[Grisolm1]

Mine did an idle hunt and behaved differently at temperature. Carb Synch cured this. If idle circuits are not clogged I'd try carb synch next.

[motorhead704]

Its been a while be for I could work on the bike due to work . after draining the bowles and cleani ng all the electric plug conn. and the run stop switch. I restarted the bike and was watching the sliders in the carb. they were all moving back and forth i noticed that the #2 carb was dupping mor gas into the carb than the rest were i pulled all the plugs and they looked like they were all runing rich they had fuel on them dose this sound like a carb sinc. prolblem thats not letting it idle. also pulled the plug wires and replaced them while checking the the plug conn for the spark plug i pulled the reisister out and the white coating was flakeing off I saw on a thread were someone had put resistor plugs in and re placesed the little resistor with a number 10 copper wire is this a good idea ? and if so what is the number for the resistor plus. bike is still not idling thanks for all the help motorhead.

[MiCarl]

You shouldn't be able to see gas "dumping" in the carburetors.

 

If you're seeing gasoline you have a fuel level problem (too high).

[GeorgeS]

Observe, the Diaphram Covers on each Carb. One, of the 4 , #2 Phillips head Screws that hold the covers in place is a " Tamper Proof " Screw !!

 

IF--- Its still in place--- ( check this ) then, The Diaphrams in your bike have Never been Replaced !!

 

Most likley at his point, you are going to have to Replace the 4 Diaphrams, and do a Re-Sync of the Carbs, ( you will need the Carb Sync Tool ) about $100 bucks.

About $65 each for the new set of 4 diaphrams.

 

Sorry-- but money well spent.

 

Also, when you pull the Diaphrams covers, Check at bottom of cover, for the Lead Seal, ( factory installed ) that covers and seals the " Idle Mixture Adjust needle jets "

 

Strongly reccomended, that you Remove the Seal, and Remove the needle jets, and Reset them to 1 and 1/8 turn CCW from the Full Closed position--

This is the agreed upon correct setting. This Information IS NOT, in the Maintenance manual.

 

Before, trying to remove the Jets, Apply Liquid wrench, several times over a 24 hour period, give the stuff time to work thru the " VERY FINE THREADS " of the needle jets. Slowly remove them, very carfull, not to damage the threads !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! IF you destroy the threads, your CARB BODY, is now JUNK !!!!

 

OK, Reset the jets, Install New Diaphrams, and then RE-Sync the Carbs. The Proceedure is spelled out in the Maintenance Manual.

Edited July 16, 2010 by GeorgeS

[dingy]

 

Strongly reccomended, that you Remove the Seal, and Remove the needle jets, and Reset them to 1 and 1/8 turn CCW from the Full Closed position--

This is the agreed upon correct setting. This Information IS NOT, in the Maintenance manual.

 

 

George,

 

Where is it that shows the 1 1/8 setting for the needle jets ?

 

Most of what I recall seeing on here is 2 turns.

 

Just asking, not arguing.

 

Gary

[GeorgeS]

Maby I'm wrong on this, its been awhile since I discussed this, and removed and re-installed my jets. Working from memory here, and I recently turned 67, so ----- ??? , the gray matter might be getting a little fuzzy !!!

 

I think its 1 1/4 for the 1200 motors, and 1 1/8 for the 1300, but I might have that basssAckwords !! --- Sombody else I'm sure will chime in on this point.

 

Usually after you do a Re-Sync ( with good diaphrams installed of course ) you can get a small improvement by doing a little retuneing of the Idle jets. However usually + or - 1/8 turn will do the trick. And any improvement will be very subjective

 

Check with V-Goose for confirmation this point.

 

The other point is to make sure you have about 1/16 to 1/8 inch of free play in the throttle " Pull Cable " at the master carb ( L , Fwd ) before the mechanical linkage starts to move.

[GeorgeS]

Question: When you had the TCI removed, did you put it in an oven, at about 110 deg. F , to dry out the Moisture??? The TCI's all have moisture inside them !!

 

Its best to do this proceedure while the wife is not home, most women do not approve of motorcycle parts in their ovens !!!

[Condor]

Maby I'm wrong on this, its been awhile since I discussed this, and removed and re-installed my jets. Working from memory here, and I recently turned 67, so ----- ??? , the gray matter might be getting a little fuzzy !!!

 

I think its 1 1/4 for the 1200 motors, and 1 1/8 for the 1300, but I might have that basssAckwords !! --- Sombody else I'm sure will chime in on this point.

 

Usually after you do a Re-Sync ( with good diaphrams installed of course ) you can get a small improvement by doing a little retuneing of the Idle jets. However usually + or - 1/8 turn will do the trick. And any improvement will be very subjective

 

Check with V-Goose for confirmation this point.

 

The other point is to make sure you have about 1/16 to 1/8 inch of free play in the throttle " Pull Cable " at the master carb ( L , Fwd ) before the mechanical linkage starts to move.

 

George, I've been doing 2.25 to 2.5 turns out on everything..... When we set the '83 in Susanville we used 2.5.....

[motorhead704]

yes I put the tci in the oven for about 45 min, I will pull the covers off the carbs in the moring and soak them intill sunday moring and try that. when I pulled them befor I checked the diaph.s they all looked good I held them up to a bright and did not see any holes are marks on them .all of them looked like they were fairly new.Could anyone tell me what the plug number would be for resistor plug .would it be better to get resistor caps or replace the little resistor with a peace of cooper wire. thanks motorhead

[dingy]

Standard plug is DPR8EA-9/NGK

 

If you don't mind spending about $6.50 a plug, have them cross that number to an Iridium plug. Better quality in my opinion and will last much longer. Still an NGK plug.

 

Gary

[Venture-N-Turkey]

Did you find the reason for your problem? I am experiencing the same thing. Bike runs great above 2000 RPM, Will not idle good and not firing on all cylinders at lower RPMs. The tach goes to zero also below 2000 RPM. I find:Venture: it hard to think it will be a fuel or carb problem. If it is why would the tach quit working? Sound like the TCI or pick-up coils but have not been able to fix it.

[mbrood]

One thing you can do... with the bike running fine at 2k pull the vacuum line off #2 carb and cap it... then slowly lower the idle until she starts to "studder" and then apply suction to the vacuum line... this should change the TCI timing enough to get over the stumble... if it does, it could be a faulty boost sensor or TCI... the #2 output of the TCI feed #2 coil, the fuel pump "timer" and the tach... if the tach drops to 0, it's a good indication that the TCI #2 output is dead at that moment... could be as simple as replacing the 8 old glass (grey and blue) power diodes (2 for each power transistor) with modern 1N4001 types. That's the main upgrade between 83 and 89 TCI units!

 

4 shown in this half of the TCI output amp section.

http://www.bergall.org/temp/venture/tci/tci1.jpg

[motorhead704]

hello everyone thanks for all the info i am still trying but she still want idle. is there any where you can get the tci unit checked and rebuilt are is there any way for me to check it. what I cant understand is why the tack drops to 0 unless there is a elec problem.the min. the tack drops she starts back fireing and idle rough it still runs but it starts loading up bad . I pulled the plugs a couple times after i ran it and all but the #1 plug were wet with gas and black #1 wasnt as bad but it had a little on it. thanks for all the help Darrell

[painterman67]

Ok now I dont know how you can rebuild or check it yourself. Really wish you was closer then we could take mine out and see if it was yours being faulty. Now as for being rebuilt there is a guy advertising that he is parting out a 90 and 91 vr in the classified section.

 

http://www.venturerider.org/classifieds/showproduct.php?product=2598&title=-2a-2a-2a-parting-a-9026amp-3b-91-vr2a-2a-2a&cat=6

 

Check out that add and call him. Not sure how good his work is but he will rebuild yours or send you a newly rebuilt one with a core charge to be refunded when you send him a rebuildable core. I do know as of the last few weeksit was 175 to rebuild one with a ten dollar fee to ship it back to you if you ship him yours and he rebuilds it then sends the same one back. He said if for any reason you fry the rebuilt one they will send you a new one one time. Give him a call , who knows. I was going to send him mine but I found one misslabeled on ebay and got it payed for and shipped for $32.33. New at yamaha is $999.99 as Ive already checked.

 

 

Ill check and see if I can send you the spare i have now. Its not mine and I'll have to ask the actuall owner. He is in the big sand box for now but will be home shortly. that will have to be his decision. Either wat good luck

 

 

david

[GeorgeS]

was reading back thru all the posts here, did you pull the electrical plug off the " pressure sensor " to check for corrosion there ??

 

Maby I missed it-- ??

[Venture-N-Turkey]

Darrell,

You probably have bad components in your TCI. I had my unit off and resoldered the pin connections. After assembling the bike I had the same problem. I tore the bike apart again and took the TCI to an electronic repair shop. There they replace several components. Reinstalled again and it runs like a beast! You actually need to unsolder the pins to remove the TCI board. All the components are on the back side. Veiwing the components removed from my board, it was amazing it was runnning at all.

 

Your problem is definitely the TCI as the Tachometer is droping to zero.

 

Hope you get back on the road soon!

[GeorgeS]

This is why I always carry a Spare TCI, with me on trips !!! I have a spare mounted on the bike, and can just swap the plugs, if needed on long trips.