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Last pic.

A recent post regarding an R5 has me reminiscing.  My first motorcycle was an R5.  I was going to Purdue and wanted transportation.  This was about 1989 or so.  Someone listed a 1972 Yamaha in the classifieds for $250.  Being the good son I called my Dad for permission to purchase it.  He says, 'no'.  So I bought it anyway.  I may have disobeyed him, but I did purchase insurance and bought proper riding gear.  Nowadays we call it PPE.  Rode it for quite a while.  Eventually it stopped running between Purdue and my girlfriend's place past the end of S.R. 25.  I'm guessing that the 2-stroke oil ran out, but then again I'm pretty sure my girlfriend's uncle told me to make sure there was oil.  This was back in the late '80's or early 90's so who knows now.  In any case, I borrowed my fraternity brother's truck and brought it back to the frat house.  I came back to HI that year and gave it to my 'big brother' in the frat.  He managed to get it to his father's farm in Monticello.  We stayed in touch and when I was financially stable enough to have it shipped to me I tried to get him to have it shipped.  That never happened.  His dad sold the farm but the buyer agreed to hang on to the R5 since I wanted it.  My 'big bro' never came through.  One of my best friends while at Purdue had a son studying there.  He and his girlfriend drove to the farm to see if they could get the R5 and ship it to me.  No one was home so they left a note in the mailbox.  The farmer called them, he had put it on the side of the road a couple of months earlier.  It disappeared before the end of the day.

Attached are the pics my 'big bro' sent me when I first asked him to take it to the dealership that was willing to crate it and send it to me.  It is still the most beautiful motorcycle I've ever owned.

Thanks M,  didn't think of using heat.  Space heaters aren't common in Hawaii, but I'm guessing a hair dryer may also speed up the process.  I'll give it a whirl this weekend.  Or maybe just put it out in the sun, if it's sunny.  Winter is rainy season here.

@ IR8D8R:  Thanks for the input.  I'll check out the potting compound you mentioned.  One of the posts I've found while trying to figure out the best way to take care of this they did mention using a vacuum method to make sure there are no bubbles in the potting compound.

As for leaky capacitors; there's WAY too much 'gunk' that's come out of the CDI to be from the capacitors, the volume of 'gunk' is larger than all the electronic components combined.  I've attached pics of the 'gunk' that I've collected so far, not including what leaked out in the box in an earlier post.  Your comment did make me wonder if capacitors can leak even when potted, and if that was the catalyst for the decomposition of the potting compound though.

I plan on making sure the CDI works before deep cleaning and repotting it.  I have a lead on a replacement that is in good shape.  It may make more sense to go that route.  There is a eBay vendor selling them, but from the description they also have decomposing potting compound.

I let the tarry substance drain for a couple of days.  Pics are what it looked like after.  I tried cleaning the sticky outside with acetone, didn't work well.  MEK did the trick but I'm pretty sure filling the CDI with MEK to get rid of the remaining potting compound would ruin the electronics.  Any ideas?

@pidjones:  What did you use to remove all the potting compound?  Right now I just have it sitting over a container and dripping out.  Eventually it will stop and the remaining compound will have to be manually cleaned out.

Sorry, forgot to mention, there is no spring connected to the center stand. There is a bungee cord to hold it up when the mc is being moved.

Sorry, for some reason I don't get email notifications, even though the box is checked.

The center stand is most likely from something else.  My friend has been working on Yamaha's bikes since Yamaha began importing them and knows what parts will work with what bikes.  If your TA doesn't allow for a center stand to be fitted I'll have to dig deeper to find the correct frame.  There is another frame that looks the same in the shop but it's painted blue.

When I have time I'll go look for that sticker.  It may or may not be there, but I'm 100% certain it's an all original TA125.  If you look at the fiche it does show an oil pump as well as two different tail sections; presumably one with an oil tank and one without:
https://www.ronayers.com/oemparts/a/yam/5978d6b887a8661120f0772e/oil-pump
https://www.ronayers.com/oemparts/a/yam/5978d6b887a8661120f07739/seat

If memory serves me correct, now that I'm thinking about it, he did mention pulling the oil pump from a race bike because the nut spun off the gear under deceleration.  Not sure what model as he raced the following; RD125 GYT kit (still in the shop), TA125 (pictured), TZ250 with a 350 top end (sold to Ed Erlenbach), RD350 (I now own it), RD400 (just finished the deal on it), and an RZ350 (I also own it).  The RZ350 is the only one that still has an oil pump.

As for the potting compound destabilizing, this isn't the first time I've seen this, just didn't remember what it was.  There are regulators, rectifiers, regulator/rectifiers, CDI's, fluorescent light ballasts, and other items I've seen leaking this stuff out of before.  My theory is that being in Hawaii we are closer to the sun, have high humidity, and high salt content in the air.  There are other things I've seen deteriorate like this, such as Lexus body panels, and the rubber on my guitar stands.  It's common for rubberized things to do this here.

Feel free to flame, if you live here.  Living in 'paradise' can be a bitch.

Thanks for the input and comments!

@m: 'potting compound'...as soon as I read that it was a 'doh' moment.  Haven't thought of or used the stuff in a very long time.  Thanks!

@teazer: ''Rex's Speed Shop', I forgot that they can do this.  Thanks for the reminder!

@SoCal250: Unfortunately we no longer have a race track, so for the time being it will just be cleaned and made as ready to race as I can get it, then displayed.

Picked up an almost all original TA125 with spares.  From what I can tell the only mods were the 2T oil pump has been removed and the oil tank bottom was cut out of the seat, maybe an aftermarket kill button.  With luck and a lot of searching I think I can find the original bill of sale.  Still has the tech inspection sticker from the last race it was in on the upper fairing.  I'm in the process of cleaning it up so I can bring it inside to put in my office.  Apparently the CDI didn't like being disturbed as it leaked a bunch of the resin type substance.  It had a little on it when I removed it so I'm not too surprised it leaked.  My question is what do I need to do to keep it from leaking more?  Do I let it drain and then fill it and seal it?  If so what do I use?  I did some quick searching and it seems there may be places that can take care of the issue, but didn't name any.

Any ideas or information would be appreciated.

O'Reilly Auto loans test equipment.  I borrowed a fuel pressure tester and noid kit to test the fuel injection on my Royal Enfield.  I'm sure they have timing lights.  I purchased a Bosch timing light that does 2 and 4 stroke engines from them for working on the dune buggy.

I was looking in the Tech Library for info regarding timing with a timing light but couldn't find a thread.  Would it be possible for someone familiar with the ins and outs of it to create a post?

Thanks

HPI ignition works fine.  Hooked up the Trail Tech TT150 regulator/rectifier per the instructions on treatland's website:
Black - Ground (- side or ground)
Red - Capacitor/Battery and lights (+ side)
Red/Yellow - Not used
Yellow 1 - input AC current coming from Stator
Yellow 2 - Also Ground

Hooked up to a 35V - 6800mF capacitor.  Output was roughly 14.40V.  Capacitor was still over 13.60V about 2 hours after disconnecting from system.  Capacitor was picked up from a local electronics parts shop for about $7.00.

Capacitor is installed in the 6V battery from my YSR50 that was bad.  I cut the top off the battery and gutted the insides, then soldered leads to the terminals, then soldered the leads to the capacitor, (+) to (+) and (-) to (-).  Still need to epoxy the top back to the bottom of the battery.  Idea is to keep the YSR looking stock but not have to worry about batteries going bad anymore.  Pics attached.  Need to drain capacitor before moving to the YSR.  I have a capacitor somewhere for the DT100A that will be installed without a case as space is limited.

I posted this as I have never seen any post containing this TB.  Was there a subsequent TB that recanted this one, or mentioned proper cable routing in its stead?

As for proper cable routing, that's something I learned early on when I first started wrenching.  I find it interesting that Yamaha would implement changes to the design of a carburetor and release a TB regarding the reason for the changes to address cable routing issues.  If the problem being corrected was related to cabling wouldn't cabling have been the topic of the TB?

Now, to open the can of worms that I wasn't going to but is directly related to the paragraph above...  More than one person I've talked to about the hi vs. low top carburetors for the RD250/350 has explained that this was an attempt to either smooth out the movement of the slide or reduce 'rattling' of the slide.  I took smoothing out the movement of the slide to mean while moving in an up/down motion (rolling on or off the throttle), and reducing 'rattling' to mean the slide vibrations side to side while the throttle was being held steady.  No one seemed to think the design change made a significant difference.

I've made posts with amusing typos and/or grammar I've found while reading the old Japanese shop manuals.  I have a feeling that the statement 'sticking slides' in the TB was in reference to the  movement of the slide, not to cables sticking, and could have been worded better.

I've seen questions regarding high vs low top carburetors at least a couple of times.  I don't recall any replies mentioning the attached Yamaha technical bulletin.  I happened to find it by accident while skimming the parts manual while on hold on the phone.  The TB shows the difference to be an attempt, "...to improve the waterproof qualities of the carburetors and to prevent sticking slides..."

I always figured the 'boot' was to keep water out.  As for the increase in slide length, I've heard more than one explanation.  Now that I've seen this TB it makes sense as the explanations always centered around how the slide moves, either the up/down motions, or from vibrations.  Basically that the longer slide allows the slide to move more smoothly.

@Clem710: PM sent, thanks