TCI Replacement 2020 It Works

[Paul Sutton]

In Entry 788 there is a mention of some improvement with the reg/rec disconnected. Has any further investigation been done to eliminate a weak magnet? If you have a thin neodymium (0.5mm x6mm OD fits ok) then glue it on top of the old magnet with epoxy to see if this improves. If not then it is easily removed.

 

[YamadudeXS650C]

Has any further investigation been done to eliminate a weak magnet?

Paul, I haven't looked into this.

If you have a thin neodymium (0.5mm x6mm OD fits ok)

I don't think I do have one, unless there is some other machinery/mechanism that has such, and that I strip it off of.

 

[YamadudeXS650C]

In Entry 788 there is a mention of some improvement with the reg/rec disconnected. Has any further investigation been done to eliminate a weak magnet? If you have a thin neodymium (0.5mm x6mm OD fits ok) then glue it on top of the old magnet with epoxy to see if this improves. If not then it is easily removed.

If the problem was a weak magnet, wouldn't the bike also run poorly on the OEM TCI? (it does not).

 

[Jim]

Paul, I haven't looked into this.


I don't think I do have one, unless there is some other machinery/mechanism that has such, and that I strip it off of.

If you wanted to pursue this Jeff, you have one TCI rotor that works fine with the GN box. Swap that rotor into the bike that isn't working right with the GN box and vise versa. That would give us a definitive answer.

 

[YamadudeXS650C]

I just called my local Radio Shack dealer, who is an hour away.
They have 2 packs of these rare earth magnets at a buck fifty each, and are willing to have me send them the cash and a self-addressed stamped envelope.
They say that they are .12" in thickness.
These would work, am I correct?

Catalog №: 6401895
$1.50

Only 3/16" in diameter, these Rare Earth Super Magnets come in packs of two. Great to be used with science projects, these magnets are quite sturdy. Along with experiments, the magnets can be used for everyday use such as holding notes on a file cabinet or your favorite pictures and drawings on the refrigerator.

 

[Jim]

I just called my local Radio Shack dealer, who is an hour away.
They have 2 packs of these rare earth magnets at a buck fifty each, and are willing to have me send them the cash and a self-addressed stamped envelope.
They say that they are .12" in thickness.
These would work, am I correct?

Catalog №: 6401895
$1.50

Only 3/16" in diameter, these Rare Earth Super Magnets come in packs of two. Great to be used with science projects, these magnets are quite sturdy. Along with experiments, the magnets can be used for everyday use such as holding notes on a file cabinet or your favorite pictures and drawings on the refrigerator.

I'm not mobile right now Jeff (long story ) so I can't get out to the garage and check, but I think you need the 1/4".... .25" magnet.
3/16" might (adversely) affect the advance curve.

 

[Paul Sutton]

I say 0.5mm thick because they worked on my SH when I had it. I do not know what the max clearance is for the rotor. Perhaps 1.0mm would work??

The magnet on your rotor may be strong enough for the stock TCI but perhaps too weak for the Gonzo????.

You could take a bit of steel wool/fine emery and polish off the top of the magnet first before switching rotors. There was a report in the last year where just cleaning the top of the magnet cured the weak magnet syndrome.

May be the best route for you to eliminating a weak magnet is as Jim says, switch the rotors (Good idea Jim, just why didn't I think of that?).

 

[Clutchslip]

I just called my local Radio Shack dealer, who is an hour away.
They have 2 packs of these rare earth magnets at a buck fifty each, and are willing to have me send them the cash and a self-addressed stamped envelope.
They say that they are .12" in thickness.
These would work, am I correct?

Catalog №: 6401895
$1.50

Only 3/16" in diameter, these Rare Earth Super Magnets come in packs of two. Great to be used with science projects, these magnets are quite sturdy. Along with experiments, the magnets can be used for everyday use such as holding notes on a file cabinet or your favorite pictures and drawings on the refrigerator.

Yamadude, I don't think you can have them sent to you in a standard envelope. The magnets will get stuck in the Postal Service sorting machinery which reads and sorts the envelopes. I don't think the envelope will make it back to you.

 

[YamadudeXS650C]

Yamadude, I don't think you can have them sent to you in a standard envelope. The magnets will get stuck in the Postal Service sorting machinery which reads and sorts the envelopes. I don't think the envelope will make it back to you.

Well, this postal experiment will certainly be an interesting one !
I'll report on the results.

 

[Port]

Update on 1981 XS650 SH

I ran the bike for the first time yesterday with the Gonzo. Sounded good choked right on start up. Stated running ruff like other Gonzos on a cold engine once i pushed in the choke. After about a 2 minutes of running it was running at almost ~39deg advance. I gave it a blip of throttle and it backfired so i killed it. was running without the airbox so was probably a bit lean which id guess contributed to the backfire. I will post a video after i get the timing adjusted later today.

To confirm before i start widening the hole on the Pick-up; shift the Pick-up counterclockwise to retard the ignition signal, correct?

 

[Jim]

To confirm before i start widening the hole on the Pick-up; shift the Pick-up counterclockwise to retard the ignition signal, correct?

Correct. Try swapping the trigger leads first.

 

[5twins]

It was my understanding that you usually need to advance the timing a few degrees with the Gonzo, not retard it, because the Gonzo generates less total advance than the stock TCI (20° vs 25°).

 

[Port]

Correct. Try swapping the trigger leads first.

Will do

It was my understanding that you usually need to advance the timing a few degrees with the Gonzo, not retard it, because the Gonzo generates less total advance than the stock TCI (20° vs 25°).

Right, i was surprised to see such high advance.
---------

I just now went to try it again in the same configuration i ran it last night. I forgot that i had unplugged the Gonzo earlier and i cranked it over without the gonzo. I stopped, plugged in the Gonzo, and as soon as i turned the key the bike backfired, with out touching the starter. Never seen that before. I guess the trigger was just left in the fire position and sparked as soon as the coil got power. I'm curious if this is any hint to y'all of what might be going on.

Edit:

Swapped the two trigger leads. seems to be better than before. seem to be getting something like 25deg advance but it starts lightly backfiring when i get above 2250 RPM so cant really check. Ill need to install my airbox first to see if that solves the backfiring so that i can get up to 3k to set timing.

 

[YamadudeXS650C]

Update on 1981 XS650 SH

I ran the bike for the first time yesterday with the Gonzo. Sounded good choked right on start up. Stated running ruff like other Gonzos on a cold engine once i pushed in the choke. After about a 2 minutes of running it was running at almost ~39deg advance. I gave it a blip of throttle and it backfired so i killed it. was running without the airbox so was probably a bit lean which id guess contributed to the backfire. I will post a video after i get the timing adjusted later today.

To confirm before i start widening the hole on the Pick-up; shift the Pick-up counterclockwise to retard the ignition signal, correct?

I don't see your Gonzo on the list:

Jeff, 4 boxes........................... all are grounded.
Steve has 1 box (dissected)...... grounded.
Jack, 2 boxes............................ Floating. Amazon sold by seller Suuonee.
Jim has 1 box........................... grounded.
Jim has 1 box (dissected)... ....... floating.
Thuban, 2 boxes.........................grounded
Jake650 1 box............................floating

Is it grounded or a floater?
.
.

 

[Jim]

It was my understanding that you usually need to advance the timing a few degrees with the Gonzo, not retard it, because the Gonzo generates less total advance than the stock TCI (20° vs 25°).

That's correct. It sounds like the same problem I had on the very first start. Here's my comment (#216 ) after the first run....
"Btw Jack, using the TCI trigger, it was definitely polarity sensitive. Connected it to what I thought was the retard sensor and it looked good dry firing it, but as soon as it started it would jump to full advance and stay there. Reversed polarity and that's what you see on the video"
Since then, I've run several tests where polarity didn't matter for a floating box, so I'm not sure what to make of all this....

 

[Port]

I don't see your Gonzo on the list:

Jeff, 4 boxes........................... all are grounded.
Steve has 1 box (dissected)...... grounded.
Jack, 2 boxes............................ Floating. Amazon sold by seller Suuonee.
Jim has 1 box........................... grounded.
Jim has 1 box (dissected)... ....... floating.
Thuban, 2 boxes.........................grounded
Jake650 1 box............................floating

Is it grounded or a floater?
.
.

Mine is grounded

 

[YamadudeXS650C]

Updated List:

Jeff, 4 boxes........................... all are grounded.
Steve has 1 box (dissected)...... grounded.
Jack, 2 boxes............................ Floating. Amazon sold by seller Suuonee.
Jim has 1 box........................... grounded.
Jim has 1 box (dissected)... ....... floating.
Thuban, 2 boxes.........................grounded
Jake650 1 box............................floating
Port, 1 box ................................grounded

 

[650trader]

What is the final objective here ? Is it to find a low cost replacement for the Tci box or
a better overall ignition ? Or ?

 

[Jim]

2 objectives:
1.) low cost direct replacement for 80 and up TCI bikes doing nothing more than making a pigtail adaptor.
2.) A crank fired conversion for 79 and earlier bikes that can be DIY'd for less than 50 bucks or so.

 

[Superjet]

I have a grounded one Yamadude. Got a timing light and may have time this Saturday once back from a trip. JC