What did you do to your Yamaha today?

Regardless of the MPG's that's a really sweet machine, when I'm riding the MPG numbers are the last thing I give a $#it about... more often the tank endurance is greater than my behind in the saddle.

 

Normally, yes, don't care much about MPG other than I'd like to know and periodically track it just to see if something is wrong.
I'm planning to go on a day trip with friends and want to bring this bike so I need to know how far a tank can go.
I normally take one my other bikes on day or multi day trips.
I'm also going to run the petcock into something to measure how much gas I'll have left in reserve too. That's good to know.
I have after market petcock now.

 

So what have I done with my Yamaha today... used it to spank a Sportster on a stoplight shootout that was totally unexpected. I was trying to put some distance on the traffic behind me when the light turned green, the Sportster next to me gunned it and we were off to the races. It was close but he never passed me and eventually ran out of breath around 117 MPH but it wasn't for a lack of effort, that hog gave me a good run. First time I've seen a chopper do a wheelie like that.

 

Need some input on a motorcycle "dashcam" if anyone is using one. I have a guy in town that has no respect for bikes and he made a right side pass on me on a split 2-lane after jumping traffic at an intersection. Took the complaint to the sheriff who said it would be a difficult one to address without an eyewitness or other evidence so now I'm at the point where I need to have some sort of a backup for the next time the guy gets stupid... thought about calling a few guys I used to work with who have patches on their jackets but I think it would be better to catch him in the act and stay within the law. That being said there are hundreds of those cameras and honestly as a professional video guy they all look cheap to me, maybe someone here has a good experience to share? If nothing else I might just mount two obsolete smartphones and use them strictly for their recording capabilities, what do you think?

Thanks in advance
Brett

 

I prefer helmet cams so that camera sees what I'm looking at so if a car comes from my side, it will capture what I'm looking at.
Honestly, this is my pseudo life insurance policy so that If I am taken by a car, my family's lawyer can sue their ass with this evidence.

I have several I use for various situations.
Ghost XL
This camera I have mounted adhesive on the side of each of my helmets. This has LONG battery life so I can record a long ride w/o as frequent charges. I typically will charge up once a week (I average 3-4 1hr rides a week)
Sound and video quality is "ok" but if someone hits me, I'll get it on video cause I almost always have this one on.
Cam does not have great stabilization
https://www.amazon.com/gp/product/B0BV9YQFQF/

I have a chin mount for go pro style cam and recently switched from a go pro 8 that I lost to this one which has good stabilization but not as good color as the go pro 8.
And $99 is much cheaper than go pro 8.
https://www.amazon.com/gp/product/B0D1JLXFRH/

Insta 360x2.
I will take this on longer group rides and is by far the best thing for capturing EVERYTYHING around the bike. I have this set up to be powered by the bike in 3 of my bikes (but not my XJ)
I had to get a vibe isolator and a 12" extension for it to work w/o premature shutting off.
https://www.amazon.com/gp/product/B099PFX52R/

 

Today I tried to ride with a group of friends to Port Dover for Friday the 13th for the first time. Instead it decided to start leaking oil from my 3rd cylinder. Lost power. Not sure what my next move is…

 

Leaking oil is never a good thing but I'm confident you'll get things straightened out and back on the road again.

 

Thanks, we shall see

 

You sure it is not the cam cover gasket above the third cylinder or it could be from further along the joint and dripping at the third cylinder.

 

Does anyone know what the link is to the schematic for the 750 SECA TCI module? Recently started having problems with one side not firing the coil and all the diagnostics point to the TCI module.

Thanks

 

As far as I know there is no schematic or datasheet for the ASIC used in the TCI

 

Thought someone had posted the schematic of the board itself but didn't have anything specific on that ceramic ASIC. Problem I'm having is a loss of signal to the base of the transistor for the 2/3 coil. Input is present and coil is good.

 

Maybe this thread

https://www.xjbikes.com/forums/threads/ic-ignitor-wip.118221/page-3

And one oddity of the TCI is if only one pickup coil is working the opposite ignition coil will fire. So if you are missing 2/3 firing, then be sure the 1/4 pickup is working too.

Is that 2/3 output stuck high?

The driver transistors for the output transistors are surface mounted on the mezzanine PCB. I found some notes where if you look at that PCB and count it like an IC (CCW from top) then pins 8 and 9 are for one channel, and pins 13 and 19 are for the other. Pin 9 and 13 are the collector outputs of the drivers, and pins 8 and 19 are the base of the drivers that is driven by the ASIC.

I found it way too hard to try and troubleshoot on the bike so I built a test set and used a couple of arbitrary generators to simulate the pickups.

 

With the level of skils in electronics you guys have I'm suprised you haven't designed a microcontrolled ecu replacement working on vacuum as well as rpm - would unleash a chunk of midrange torque? Arduino has been done I think.
I built one a few years ago that did fuel and sparks - sparks were the hardest since you have to equate time with degrees of rotation at the particular rpm to get the timing right.

 

I ended up doing a bench test feeding the TCI a square wave from my function generator and scoping things out... I have a stereo microscope for doing surface mount and did a close exam of the ceramic monolith and found a hairline stress crack running across the pads where the pins are soldered and running thru the one printed resistor, needless to say it's done. For the time I'm going to go after a used TCI from the evil-bay but as minimuttly pointed out there has been some progress made with the arduino but I'm not a code writer or low-level programmer so I'd have to rely on whatever half-ass code that's out there already. I'm a retired Motorola radio tech with over 40 years of experience so fixing the TCI would be easy if the unobtanium ceramic ASIC wasn't broken. They're made by Hitachi, the same company that brought us cheap-ass VCR's during this same time and honestly I'm quite surprised it lasted this long. The crack looks to be the result of years of vibration and the poor wave soldering of the day that gave out on some of the pins allowing the wafer to crack.


The timing issue can be addressed using degrees of trailing spark similar to what GM did in the 80's with the Computer Command Control. Take the input pulse as the zero point and subtract enough ms to equal 350 degrees trailing, to the distributor coming up on the next cylinder that would equate to +10 degrees over whatever the baseline of the distributor was clamped down at (8BTDC for Olds 307) making the total timing +18 BTDC using the previous spark input to start the timer. It was known as the "spark echo" and the pulses were one cylinder behind in the mind of the computer which ran a Motorola 8-bit masked processor. Somewhere in this mess I have an actual schematic of that archaic pile of junk made by Delco-Hughes

 

Update. Found another XJ750 TCI module for $100 and replaced the capacitors in it, had to go thru and rework all of the solder connections & traces as water got in an corroded them from the terminals. Everything got conformal coated and I put another 40 miles on this morning. Runs about the same and that cold autumn air really makes a difference on the midrange power.

 

How difficult are they to repair for an electrical novice like me? Has anyone done a how to video on these repairs?

 

You had to remove conformal coating to get to the solder joints and remove the Caps? If so, how did you work thru it? blade or a solvent or heat?

 

Repairing these isn't difficult for a veteran technician, unfortunately I can't say how that would be for a novice as everyone has their strong points regardless of experience. What I will say is the biggest challenge of the TCI board is not damaging or destroying the traces on the board. These were OEM by Hitachi and in the early 80's were not known for their robust construction & manufacturing practices, add another 40+ years of temperature swings to the mix and things become fragile. That being said a little care and experience with a quality soldering iron and desoldering equipment will get the board out of the box. It is secured at the bottom where the connector spades run thru and they're positioned in a way to index the board and maintain alignment with the two countersunk screws used to hold the heatsink on the back.
Once the board is out it can be cleared of the factory conformal coating using acetone on the back of the board only. Reason for this is the acetone will take the plastic sleeves off the capacitors and make life difficult, there are two each of 0.47uf, three each 10uf in a row and one 2.2uf at position C9 nearest the ceramic LSI which is the "mystery brain" of the whole module. This guy does the timing processing and drives the switching transistors to fire the coils and it is very fragile as I have found out. Cracks or breakage can not be fixed despite my 40+ years of experience. I don't know what the functions are of the capacitors or how critical the values are, if you're going to replace them I'd strongly recommend going with a real Nichicon or Panasonic (Matsushita) made part with a 105C temp rating. I used Nichicon UXY series caps which are rated for 135C and 40G vibration, these are specifically designed for the automotive market and are available from DigiKey and Mouser Electronics. You will need to order them as 50V rating as this is what was found in the TCI module.

There's no YouTube How-To video to fix these that I know of, honestly I try to avoid the YouTube flix simply because the guy doing the whatever may not be doing it correctly himself and as a former service writer & photographer I'm very concerned with the viral spread of misinformation. It is of utmost importance these modules are done correctly using high quality parts... unless you like walking away from your bike on the side of the road.

If you have the desoldering skills, equipment and experience the repairs are not that difficult, the board uses plate-thru pads that are easily yanked out so you want to be absolutely sure all of the solder has been removed before pulling the part. The solder used on these is not a very good quality being an early generation wave process and the plate-thru holes are contaminated, they will outgas and bubble when you solder them.

So lets say you do accidentally pull up a trace. It's not the end of the world and is easily fixed with some thin solid hook-up wire. I scraped the green mask off the traces leading from the bottom connections to the leads of the transistors themselves and soldered down runs of solid copper liberated from CAT-5 cables. A full twist around the lugs gives everything a strong mechanical bond but don't solder both ends right away instead solder the one at the lug after a full wrap then using a small jewlers screwdriver bend and manipulate the copper wire to follow the trace to the destination and wrap it around that connection then solder, this way expansion won't pop everything loose. This is one of those things that comes naturally to me having done it for so long but it's not easily explained in a way that's easily understood by all.

Once everything was buttoned up I sprayed the board with Krylon clear acrylic using thin layers. There is a gob of adhesive used by the factory to sort of secure the capacitors together but sometimes it drips down, the problem here is this adhesive is known to break down over time and become conductive enough to cause problems. I recommend removing it from the board and any connections it may be bridging, doesn't matter how "clean" it looks it's a long known problem with Japanese electronics of this era.

So I did a few runs this evening and while it's hitting on all four jugs it doesn't feel as strong, I run the Dragger app on the phone which is secured to a cradle on the headstock and it reports a measly 21.26 seconds for 0-100 MPH hitting a top speed of 102.83 @ 26.53 seconds. What really sucked was the 1/4 mile times of 14.42 @ 92.53 MPH... This bike has run 12's as recently as July when it was 15F warmer. Launch times were good but 0-60 is 6.20 seconds, a full third slower than before the TCI failure so I need to figure out what's going on here. It says SECA but it feels more like a Vespa.

 

Thanks for your in depth reply. To be honest l would do more harm than good l think. I thought it would be a challenge for a novice.