Can't I go a week without an issue???

[Patch]

LOL

Must say you seem be working with much diligence, nice to see.

A pic of the for plugs would be nice to see from the bottom looking up. Quick building carbon on plugs such as these almost new ones is a sign of poor combustion heat. 

The good news is your coil voltage reading are close to the battery voltage, a sign of a good harness.

The gap test should be a minimum of 7/16 th if memory serves. What causes this high voltage is the secondary side of the coil. Now this is also very important, a cold reading is or can be misleading. I find a quick check for spark test at least gets us started as me might get lucky. But its the hot coils that cause the intermittent problems more often. 

Check with the gap tool checks the whole system the probing of the individual components is confirmation and where the money gets spent.

nice work 

[JFootman]

Sorry, @circa1968. Probably wrong question. Not needing the “spark plug gap” but rather when I test the spark gap with the spark tester, I didn’t know the recommended minimum gap to indicate adequate flow to the plug. Looks like 10 is minimum and 40 is max. 

[JFootman]

Spark testing revealed “20” on all 4 cylinders. While my tester has markings for 10, 20, 30 & 40, the distance between the 20 and 30 appears twice the distance between 10-20 and 30-40 however when I split the distance none bridged the gap. On the same page in the service manual (yes, I missed it!), it appears they indicate the minimum spark gap is 6mm so I guess that's a good sign.

On the primary coil test I got 3.3, 3.6, 3.5 & 3.4 respectively on 1-4. I tested #1 twice and got 3.6 on second test. The manual indicates 2.7 ohms +/- 10% so I'm above the 2.97.

Admittedly I may have not done specifically what you've asked, @Patch so let me know if I need to redo the testing. I unplugged each coil and inserted the leads into the back of the coil side plug which were all orange wires and red/white stripe wires. I assumed the colored wires wouldn't test the coils unless I was to leave the plugs intact. 

I'm trying to test the secondaries but must be doing it wrong. I'm placing 1 lead on the orange wire at the plug and the second lead in the plug cap (also tried the red/white stripe wire). I'm not getting any reading whatsoever (I've tested 3 of the 4 with no reading). I set the multimeter at 200 ohms for the primary and set it at 20k for the secondary testing.

Sorry to be the pest with such basic testing but again, thx for your help.

Edited July 5, 2021 by JFootman

[Patch]

Well I'm going to print this off and look at the schematics again. Surprised a bit that the color codes are only two colors.

On the other hand if I am reading this correctly the coils are firing.

You say measured twice but at what temperature?

So I'll right a new list of known symptoms as listed in the thread.

A question: When the bike is running is it charging?  

[circa1968]

2 hours ago, JFootman said:

Sorry, @circa1968. Probably wrong question. Not needing the “spark plug gap” but rather when I test the spark gap with the spark tester, I didn’t know the recommended minimum gap to indicate adequate flow to the plug. Looks like 10 is minimum and 40 is max. 

my bad.  sometimes reading comprehension oversleeps in my world

[Patch]

OK if you go back to post 8 looking at the coils the red/white wire is the path to the secondary side of the coil. So if you probe from the red/white wire to the end of the high tension cable there must be a reading. You've proven they fire so the can't be open or broken.

The next thing that is troubling me is the burn boot. I'd like to see a pic of the plugs say with the cylinder # showing.

Often we have seen these old bikes with modified jetting. This can lead to heavy carbon build up which leads to detonation problems. This takes a compression test to be able to rule on. You can borrow the tester from a local Indy shop.

[JFootman]

@Patch, shouldn't you be out partying it up? Of course here it's only just 11:30 here so the night might be young where you are!

So the orange and red/white stripe wires are on the coil side of the plug. The 4 different colored wires were on the sides leading TO the coils. Sorry if I didn't clearly indicate that. You didn't say to unplug the coil but I just assumed and since I was cleaning the contacts and applying dielectric grease it just made sense to me.

The spark on all 4 cylinders were similar ("20" on my tester which looks less than 20mm but definitely greater than the 6mm minimum) so yes, it appears all the coils are firing and if I'm testing correctly the ohm test confirms the primaries functioning as well.

I've not tried to "baby" it to life since I parked it a little over a week ago. Like I said, it'll start but definitely struggles and seems like it's only firing on a couple of cylinders (to my ignorant mind!). Everything has therefore been done on a cold engine.

I can try to get it running but not sure how to test if it is "charging". I've not had to put it on a battery charger except after I tried to start it after cleaning the carbs therefore if you're talking battery charging from the alternator, yes it appears to be charging the battery.

With the multimeter set on 20k, I've placed one lead on both the orange and the red/white stripe wire from the back and the front of the plug with the other lead on the spark plug cap terminal. As you indicated I'm sure they're not open but again feel like a boob that I can't test them appropriately.

While I didn't ask him specifically and neither did he share, the previous owner most likely didn't rejet it himself and he purchased it from his brother-in-law so at least he knew the history going back to the first owner. Again, that doesn't mean it WASN'T rejetted but it didn't sound like that was the case. I was already looking at a borescope/endoscope which might enable me to look within the cylinder but as this seemed to be a sudden onset I'm not sure if investigating in this manner would benefit me (other than having a "cool" toy!). While I can check with a local bike shop, we've only got one in our small town & he acted like they were slammed and will likely be disinclined to allow me to borrow a compression tester (unless I can "borrow" one from O'Reilly's, AutoZone or Advance Auto).

Attached are the pics of the cylinders with boots on & off. #2 is the burned one & #4 is the "oily" or dirty one. #1 & #3 look "old" or worn but nothing outstanding (to my untrained eye).

Should I go ahead & pull the plugs to investigate further? As I mentioned I have new plugs on hand and new wires & caps/boots that should be here before week's end. I can install the plugs now & add the wires and caps when they arrive. If I'm getting ahead of myself I will hold off.

Thx!!!

[JFootman]

Well, GOOD NEWS! While researching where in tarnation this TCI unit is and thinking I'd clean its contacts I stumbled on THIS thread from 2016. Specifically saw Yamagirl's post #7 where she encouraged inspecting the connector on the left side under the seat that goes to the pick up coils. There were 3 plugs there and all three were severely corroded however the plug going to the pick up coils also had a connector that had been pushed part way out of the plug probably making poor contact as well. After cleaning all 3 and applying dielectric grease I held my breath and BAM! Started up almost immediately and with NO CHOKE!

Knowing my luck, I wasn't ready to stop especially with all the issues I've heard about the connections going to the TCI unit so I dove into that as well. Definitely not the easiest thing to get to but since I had just cleaned the carbs on Friday I was comfortable pulling the airbox off and the battery box wasn't too difficult. Of course I pulled all connectors and cleaned and greased all the connections that I encountered. Sure enough, horrible corrosion on both of the TCI plugs and one of the contacts had apparently arced at one point with very slight burn on the connector. For some reason there was water on the connectors so I'm not sure where that came from.

Took it for a quick spin up the street & I know there's the "I fixed something so it runs so much better" mentality but I seriously don't think it's run this well since I got it. I've started it 3 times now cold with no choke and starts immediately. I know that doesn't solve the burned #2 cap and the wet #4 cap but at least she runs!!!

The only bad news is I also did the master cylinder rebuild tonight as my first post in this thread indicated a locking up of the brakes (possibly overfilled MC?) but also the propensity for the rear brake pedal to not return upwards (I've cleared the return hole twice already). I purged the lines by "back bleeding" as the fluid was replaced less than a couple of months ago. Filled the reservoir and bled the rear and then the front until no bubbles (probably upwards of 20+ bleeds each). Unfortunately the pedal still doesn't want to return to the full upwards position. I know CowPuc has a video of bleeding the metering valve at the stem but despite hitting it with PB Blaster on more than one occasion I can't crack that fitting to save my life. I might give it a try again although last time I torqued it so much the metering valve started to rotate so I'm worried I'm going to damage it or one of the lines. Either way, I'll bleed them again tomorrow as it's nearly 6am here and I'm apparently rambling more than I usually do!

A special thanks to all who have chimed in giving me directions and especially @Patch for his expertise, patience and guidance. One thing's for certain, I wouldn't have a bike still if it wasn't for this forum and all of your guy's support!

[Patch]

Yaknow new members like you, problem child 1968 and others make this club a cool hangout.

Unfortunately no chicks swept me off my feet Saturday night so I made it home relatively early; tho I was feeling somewhat like Kris singing Sunday Mornin....

Well good onya

The brake peddle sounds like a week return spring and some lube needed on the bush the peddle pivots around.

 

[circa1968]

1 hour ago, Patch said:

Yaknow new members like you, problem child 1968 and others make this club a cool hangout.

Unfortunately no chicks swept me off my feet Saturday night so I made it home relatively early; tho I was feeling somewhat like Kris singing Sunday Mornin....

Well good onya

The brake peddle sounds like a week return spring and some lube needed on the bush the peddle pivots around.

 

 

Dad, I promise to stop being a problem child, but the bad jokes voice in my head is hard to stop sometimes...  And I agree, cool place to hangout, learn, help, laugh, etc.  Thankful to all the foremembers here.

[Patch]

For kinky guys like myself that enjoy fooling with combustion and have spent in excess of 10gs on a single experiment I have had my share of wins and losses. I found this video looking for simple demonstration of the dynamics at play when charging a combustion cycle. The CV carbs are much more complex but the principles at play remain. We have some threads here where we dive into fluid dynamics CV carbs.....

Just one other comment: Today we can choose to not use a throttle plate to control air/fuel charges. This in turn causes other effects such as decreasing vacuum but that decrease also lowers piston drag making for quicker response and more energy delivered to the crank. Has a lot to do with the HP/torque ratings we can achieve with smaller displacements.

Now you know what I know;)

Show the vid to the kids

 

Edited July 5, 2021 by Patch

[JFootman]

Sorry, Patch. Got my days mixed up. The ladies don't know what they're missing I"m sure!

I literally just watched that video a few nights ago! Very helpful for guys like me. He's the kind of person I see nearly everyone on this forum being like... brainiac's especially when it comes to bikes! I've always been told to surround myself with people who are more intelligent or more advanced in what area you have an interest in and this forum surely has it!!! Y'all are great and enjoy the camaraderie. Looking forward to the time when I can give back!