Replacement Voltage Regulator/Rectifier Sourced and Installed

Once I figured out that I needed a new Voltage Regulator/Rectifier for Oldbike the first thing that I did was call a local shop have I had been mentioning in a few of my past posts to see what they had available.  They informed me that they did not have any used Voltage Regulator/Rectifiers available and the new ones that they had were $100.  After I called them I checked with a local motorcycle bone yard that I have been going to for parts, they told me that they had used ones for $45 and non OEM one for $100 (after testing their used ones I wasn’t able to get one to give me a good test to that option was out).  The next place I went to was another local shop that is doing their best to stay afloat and in the last few years hasn’t been carrying too much in stock and mostly order odd parts, so of course they didn’t have the part in stock but they were able to order the same non OEM Voltage Regulator/Rectifier for $79, so far that was looking like the deal to go with.

Until I went to an site tied strongly with GS Resources, BikeCliff’s Website.  He had the eventual solution I went with laid right out there for me.  He had a list of other manufacturer’s compatible Voltage Regulator Rectifiers, a tutorial on how to modify them for use on the Suzuki GS and even a tutorial on how to install them!  Using all this valuable information I found a used Voltage Regulator/Rectifier for a 1979 Honda Goldwing that would bolt right and work perfectly with a little wiring work.  I got it off eBay already tested good from a power seller (shipped) for $24.  For that price it was worth the risk of getting a bad one and the wait for it to get there.

Amazingly it arrived in two days!

You can see (above) there is a size difference between the two (more surface area = more heat dissipation capability) but importantly the spacing between the two mounting holes and the size are exactly the same.  My came plan was to cut the wires off my old Voltage Regulator/Rectifier and re-use the stock bullet connectors.  Some people go through an extra step of putting new connectors on, I think that if you clean up the contact points and you get a good continuity test what does it matter? Electricity doesn’t care how old your connectors are.  Also, my soldering skills aren’t the best so I figured the less soldering I do on the bike the better.  The first thing I had to do was to get the Honda plugs off of the new (to me) Voltage Regulator/Rectifier.  Really I could have just cut the wires but I figured that some people might wonder how to get them off without cutting.  Basically you just something narrow enough but stiff enough to jam down into the end of the plug, below I am using a cotter pin, I have tons of them in my odds ‘n ends toolbox.

All you need to do is press your tool of choice where the notch is in the connector, that will press in the little tab that keeps the plug from pulling out of the connector and you can slide it right out.  Just like that you’re connectors are out!

Then I went ahead and cut them off anyhow!

I cut all the connectors off the old Voltage Regulator/Rectifier, stripped the shielding back and soldered them to the corresponding wires on the new Voltage Regulator/Rectifier.

On the Honda the tree phases are all yellow, so you can pick and choose whatever of the GS phase colors (yellow, white/red, white/blue) go onto what yellow wire, electrically it doesn’t matter which one.  Another difference is that on the Honda part the ground wire is green NOT BLACK.  The black wire on the Honda part is a sensing wire, this can be connected to any wire that is always on when the bike ignition is in the on position.  The reason that it needs to be that way is that the sense wire tells the Voltage Regulator/Rectifier what the system voltage is at any given time, so if the bike start’s putting too high of a voltage into the electrical system the sense wire tells the Voltage Regulator/Rectifier and it lowers the voltage coming out of it.

I also have a ton of different colored wire of different gauges in my odds ‘n ends toolbox.  And being that I was going to be running the (green) ground to the negative post of the battery rather than to a common ground (the frame) I soldered in a length of green wire more than sufficient enough to get the batter which I would trim once I had the Voltage Regulator/Rectifier installed onto the bike.  I did the same with the black (sense) wire.

After all the soldering was done I took everything to the bike and mounted it on there.

I made a video walking you through what I did which you can watch below.

All that was left to do was to test it you can see how that goes in the video below.

I have ridden it a few times since then and so far the highest voltage I have seen is a peak of 14.8V and with the bike warm and the battery fully charged it will put out around 13.0Vat idle I would say that is acceptable to me! Of course time will tell how this used part holds up hopefully it doesn’t burn up in a week and I feel dumb for not spending the $79 on a brand new non-OEM one!

Thanks to all who view this blog!  Stay tuned for my next post where I try to take Oldbike to the Slimey Crud Run next weekend.  If you don’t know what that is you can check the link!

Charging System Diagnostic Tests

Yesterday I continued working through the diagnosing the problems with Oldbike's charging system. A few days earlier I checked the voltage at the battery with the multimeter and found that the bike was not generating enough voltage to charge the bike.  So I went through and checked connectivity between each of the connectors using the multimeter but beforehand I cleaned all the ends as you can see in the above picture.  I did notice that on some of clear rubber shielding that there were what looked to be burn marks some really bad like the on the voltage regulator/rectifier lead.

The leads on the two of the other voltage regulator/rectifier leads also had small burn-type marks on their shielding.

I made a video of all the steps of the test that I did so you can see the whole process that I worked through and the results.

All these steps are listed on a diagnostic sheet of "The Stator Papers" on GS Resources.

In the end it would appear that I have a bad voltage regulator/rectifier.  I called around and it would appear that there are two local shops that have a non-OEM replacement part for $100 and one of those places also carries used ones for $45.  I went to the one that had both and did the same test that you saw me do in my office on the rectifier with the same results on one that looked similar to mine off an 80 GS 425, all of the other ones were different sizes and from different hear GS models none of which seemed to pass the tests as listed out on "The Stator Papers."  He even let me test the new non-OEM one which seemed to not pass either.  At which point I began to wonder if I was doing the test right!  He suggested that I bring my bike over and that he would let me hook the used ones up to my bike and see if any of them worked which seemed like a great suggestion so back across town I went to get the Oldbike.

I connected the multimeter to the gas cap cover on the gas tank so I could see how the voltage across the battery behaved while I was on the ride there.

It's about a 15 mile ride one way and if I take the fast way it would be a sustained 60-ish MPH and about 20 minutes which I have never done on Oldbike before or it would be about an hour one way to take a street level route.  I opted for the fast way.  The bike performed fine but of course there were a few issues that came up.  I don't know why I didn't test this in the first place but I remember reading on "The Stator Papers" that one of the phases bypassed the voltage regulator/rectifier (something to do with people riding more with the lights off in Japan).  So on the ride over I switched off the lights and the voltage went from a steady 12.4-ish Volts to a varying 13.8-14.8 Volts which varied with the engine RPMs.  As of right now I'm not sure what to do with that information but I figure that is worth mentioning.  The other thing that happened was that another damn bolt vibrated it's way loose, this time it was one that mounted the headlight bucket to it's bracket.

Luckily I noticed this and was able to grab the bole before it fell and pocket it.  I pulled off the road and finger tightened it back up enough to make it to the shop where they guys let me use some tools to re-tighten it properly.  Note to self: put together a tool kit for riding Oldbike.

The bad news was that none of the voltage regulator/rectifiers they had did anything to fix my problem.  I thought about buying one of the new non-OEM ones right then and there but it only had a red wire and a ground, the other three were all yellow and I wasn't sure if that would be right and wanted to bounce that off some forums first it seems to me that if the order in which the wires were hooked up coming out of the voltage regulator/rectifier that the OEM would not have been color coded (maybe I'm wrong).  None-the-less I decided that it didn't need to be done right away and I'd go in search of feedback first.  On that note that is where the project sits as of now she ran well at sustained speeds which is good news though riding on a three-lane highway on a 425 is not going to be one of my favorite things to do ever.  If any readers have any suggestions or feedback please comment below!

As always thanks for reading!

Things Come Up When You Ride an Oldbike

Since I registered Oldbike I have been trying to use it as much as possible in a sort of commissioning process just to see what issues come up.  Some of the things that have come up I have already talked about in other posts because they were big issues that required an entire post or two to cover what I did to rectify the issue.  With this post I just want to cover some of the other little things that have come up as I have been “commissioning” Oldbike.

I work rotating 12 hour shifts that start or end on the 7s this early in the year I have been commuting in the dark (yes those rides have been cold) one thing that became immediately evident the first morning that I rode the bike to work was that the backlight for the tachometer was burned out.  You would never notice it during the day so that was the first thing that I decided to fix.  Unfortunately I didn’t take a picture of the tach in the dark with the light burned out but it was hard to see in the early morning with my tinted shield.

There is only one bulb in the back of the each dial gauge.  Getting them out is as simple as removing the two nuts on the back of each gauge and pulling out the rubber socket that holds the light bulb.

The bulbs in the my speedo and tach were the original Toshiba bulbs bearing the numbers A12V3.4W (basically calling out that they were for a 12 volt system and that the bulb rating was 3.4 watts) on it this bulb is not made any more so I took the bulb to Batteries (& Bulbs) Plus nearby and they found the most comparable replacement they could with a matching sized base and a slightly larger bulb but that would be the tiniest bit brighter (3.6 watts Vs. 3.4 watts) than the stock ones were but not tax the electrical system any more.   The replacements were EiKO brand Model #1893.

They did exactly what they were supposed to do, it will be nice to be able to tell what rpm’s the bike is running at on those dark rides.

The next fix I had to do was find a permanent mounting place for the license plate.  You can see my solution below.

The mount is made up from the remainder of the tail light/license plate stalk that I cut up to make the shorter tail light stalk earlier.  I cut a small section out of the remaining bottom portion and pounded it flat (see the detail picture below to get an idea of what I cut out).

Then I located the center line and drilled two mounting holes in the license plate bracket and then lined the bracket up below the tail light which is clear on the bottom to illuminate the license plate (a rule at least in Wisconsin that I know a few people have been pulled over for breaking).  I have to admit to using standard nuts and bolts washers and lock washers for this.  They are just so much cheaper than their metric counterparts.

The next issue came up on a ride back home from work after a night shift one morning but I want to start with the ride to work and work forward from there.  I had noticed that as I was riding the bike to different places that the bike seemed to be having a slightly harder time starting each subsequent time.  Undaunted I started on my way to work that afternoon.  Normally on days that I work nights I like to head into work much earlier to avoid the chance of traffic headaches and afford myself a more Zen state of mind when I have to start my workday.  I started the bike and the starter barely seemed to want to turn over but the bike roared to life and I rode the bike downtown.  I stopped over at Qdoba for some free chips and queso that I had received as gift for my Qdoba card registration anniversary (I used to eat a lot of Qdoba).   Back at the bike there was no joy when I thumbed the starter button the lights dimmed and all I got was a click the battery seemed to be dying.  Being that I was already closer to work than home I decided to try and kick start the bike.  That worked right away, and I was off to work but the ride was not going to be a good one.  Twice as the idle dipped, the bike stalled and this was in pretty steady traffic so both times I had to push the bike out of the way to kick start it again. At one point when I was new to Oldbike I told the guys on Caferacer.net that I wanted to get rid of the electric starter to “save weight” to which one of the members stated (I’m paraphrasing here) “…why would you do that? Do you want to be the jackass who is holding up traffic while you try to kick start your bike after you killed it? Or would you rather just thumb the button and go?”  I thought of that moment both times as I wheeled the bike to the side of the road realizing that all those people DID think that I was a JACKASS and that I would definitely have to figure out what was wrong with my starter.  I made one more stop at a Ground Zero a coffee shop near my work and had to kick start the bike when I left there and rode the two blocks to work where I had the next 12 hours to wonder whether or not I would make it home seeing as how the bike had already stalled twice in traffic.

The next morning it was COLD…

...and I was tired.  I had brought a pair of riding pants to go over my jeans and an extra layer to go underneath my jacket as well as some snowboarding gloves to wear rather than my regular riding gloves this combination had worked well in the high 40s but 3 degrees above freezing is a whole ‘nother story.  One thing that I hadn’t anticipated was how hard it would be to lift my leg high enough to kick start the bike with the two layers of pants on this was a chore.  Also I had left my gloves and helmet off for ease of starting, what I hadn’t planned on was that it was so cold that the bike wouldn’t idle high enough to run so every time I let off the throttle to put on my gloves and helmet the thing died and I had to kick start it again, I did that twice before I put on my gloves and helmet before kick starting the bike a fourth time, hopping on and speeding off towards home.  The cold on the ride home was tempered by the fear that at any moment the bike would quit on me and leave me stranded, and the half awake half asleep haze that you are in after a night shift.  To make sure that this didn’t happen I kept the throttle at 2,000 RPMs at all the stops as the bike seemed to die when the RPMs dropped too low.  Luckily I made it home though when I looked down I saw the top triple clamp bolt was gone.

I had never really checked the torque on it and it must have been working it’s way out for some time and worked it’s way out on the ride home helped along by all the high rpm stops to keep the bike running.  Not spending too much time thinking about it at that point I went inside to warm up and went to sleep.

Two days later I went and checked online and found that an OEM replacement head bolt and washer would be around $7, not too bad but as this is a budget project I felt obliged to see if I could find a generic replacement bolt that would fit locally for less.  I did some internal measurements of the threaded portion of the steering stem and my best guess was that it was a M12 fine threaded bolt and the thread depth seemed to be about 20mm so I had my target I just needed to find one.  Sadly my go-to place for fasteners Dorn True Value struck out on this one they only had an M12X20mm in coarse threading.  So I stopped by the Menards near my house and found a M12X25mm fine thread.  I thought that this would work if I took into consideration that I was measuring from the top of the steering stem which was recessed a bit in the top triple clamp and adding a flat washer to this and a lock washer I took a gamble and bought the only M12X25mm fine thread bolt that Menards had.  Fortunately I was right and the bolt worked perfectly.

I also took the opportunity to look up all the torque specs for the respective bolts in the steering system and to properly torque them down.  A cool thing was that the castle nut tool that a friend of mine made for me years ago for my 2002 SV650s fit perfectly onto it's 23 years older brother's castle nut too!  I wonder if they use the same machine to make those nuts?

Now the bigger issue was going to be what to do about the starting issue I was experiencing.  You can’t do any good electrical diagnostic testing without a good, fully charged battery.  I noticed that the acid level on my battery seemed a little low and since I had just recently bought Oldbike’s battery and it was a Yuasa a “good brand” I called the place I bought it from the Engelhart Center and asked if the low acid might be causing what I was experiencing they weren’t sure but they offered to re-fill the battery, fully charge it and test it to make sure it was good free of charge (even thou later we would find that it was 10 days outside of it’s year warranty). 

I thought that was really cool of them and in the end the battery came back to me testing good so that was not the issue but something was draining the battery.

After finding out that the battery was good I set about fixing a glaring issue that has bothered me from the first time I looked at the bikes battery closely for the first time.  The positive wire from the battery to the solenoid was very frayed and looked like it had been cut shorter and had new ends put on it at least once if not twice and due to the age and the angle that the wire had to bend the wires were brittle and breaking.

I also wanted to replace the old tube style main fuse with a blade style fuse.

The OEM replacement was listed as unavailable but Motorcycle Performance at least had a single wire replacement that I could modify to be like the OEM one.  You can see it in the picture below along with the in line blade style fuse replacement I used.

The only issue that I talked trhough with an EE friend of mine was the gauge difference between the connectors I wanted to splice at each end of the in-line fuse.  After some discussion we came to teh conclustion that being that the only fuse in the system is that fuse that and all of the other wire is the same smaller gauge that it shouldn't hurt.  I am still open to comments on this as I don't want to be stepping backwards in reliability the blade style fuse is supposed to be an enhancement so if you have comments or suggestions on this front feel free to share them.

Of course I solderedall the connections.

I thought about doubling the connectors back but the with the extra length of wire I added I figured why add the extra stress to the wire so I civered them with shrink tubing as is.

The last thing I needed to do was to remove the factory applied shrink tubing from the replacement wire and trim back some of the shielding cable to attach the break-off for the bike power supply...

...solder the connection...

...and re shrink-tube the connector and wires.

Here is a shot of the "new" wiring.

And here it is back on the bike.

For fun I took a picture of my life's worth of odds and ends that I have collected throughout the years. This is all the stuff that as a man you keep because you "might need it" at some point. Am I ever going to need a steering wheel puller or a lock plate compressor? Probably not, but it's in there :-)

The next test I did was to see if the battery was being charged by testing the volts through the battery as the bike was running.

I used this helpful YouTube video as a guide on how to do the test.

Below you can see my test and results.

Right now I am poring over “The Stator Papers” on GS Resources.

Stay tuned for my next update where I will start working through the different array of tests to run down my charging system issues.

Thanks as always for reading!

Petcock Leaking Issue Solved

After the last update on the blog I called around and asked some places if they had a replacement petcock spring available for individual purchase, they didn’t and I got the same advice again, to stretch the spring back out along with a suggestion from the boys at Motorcycle Performance that I try a different o-ring for the vacuum plug (from a Kawasaki that uses the same style petcock) If anyone is interested I can look up the part number I have it written down.

Now I’ll start with the good news, I did get the petcock to work as prescribed and am no longer experiencing leaks, even with a full tank of gas!  The bad news is that I couldn’t tell you exactly what was causing the issue for me, I ended up doing three different things while I had the petcock apart and now I can’t be sure of which one really solved the problem.  If I was getting paid to do this I would take it apart and try each fix one at a time to answer the question fully for any other readers that may be having the same issue but alas I am not.  What I will do though is list off the three things I did countdown style starting with the least likely to have been causing the leaks and ending with the most likely.

3. The o-ring: Once I got the petcock apart, I compared the new o-ring to the one that came with the petcock rebuild kit and it was the tiniest bit thicker than the other one which I would imagine would move the contact point a little further up on the tapered hole where the valve seats itself possibly giving the spring a little more oomph to keep the valve closed.  I really don’t think that this was the solution to my problem it didn't hurt things but as you will see there are more likely candidates for the cause.

2. The Spring:  This could very well have been part if the issue and I could tell that after I stretched it again that I had gotten about 1/8’ more length on the spring and when putting the petcock back together the resisting force when I compressed the three sandwiched pieces together was a lot stronger than before but I still think that the last change was the real culprit.

1. User Error: The one thing that I like to do whenever I am having a problem with anything is to talk it through with someone else, a lot of times you come to a solution just in the process of explaining the problem.  This was no different I brought the empty gas tank, the gas and my testing setup over to my buddy’s garage to see if we could make any headway working together on it.

I started out by talking through how I thought the petcock worked, we would look at each hole and see if we agreed on what it did and why and then move onto the next component of the petcock and try to determine the function of it.  Then we got to a tiny hole, it’s location is difficult to describe so hopefully the words along with the pictures will do a good enough job.  If you divide the petcock assembly into a front and back the front being the side with the switch on it and the back side of the petcock being the portion that houses the vacuum actuated valve we are dealing with the back portion.  Now in regards to just the back portion, that is broken up into three pieces the front sandwich piece (the main body of the petcock, the middle sandwich piece (the gray plastic piece that goes between the vacuum petcock diaphragms) and the back sandwich piece that has the vacuum tube flange on it).

As we were looking at things we noticed a tiny hole on the front sandwich piece of the back portion of the petcock. 

Then we noticed that the diaphragm material that goes between the front sandwich piece and the middle sandwich piece also had a similar hole as did the front side of the middle sandwich piece.  This did not go all the way through the piece instead the hole went into the center “ring” of the middle sandwich piece.  The key point that needs to be mentioned is that, I did not have these three holes lined up when I reassembled the petcock.  I didn’t even realize they were there.

After some thinking (and drinking) we deduced that the holes made sense and that they were there to make sure that there was not a vacuum in between the two diaphragm membranes.  If there is the diaphragm will not move keeping the vacuum plug from closing and just letting the fuel come out at will.

The reason that fuel doesn’t come out the hole is all the tiny ridges that you see create individual seals that keep the gas in and allow the air to purge out from the between the membranes as they move in and out.

So after I aligned all the holes properly and stretched the spring and replaced the o-ring I re-assembled the petcock and tested it.

I started out just only putting about a quart of fuel in and when I didn’t see any leaks I out the rest of the 3 gallons in and we set about to the work of beer drinkin’ and smart talking and waited for the fuel to start leaking out… It never did!  I did put the petcock to prime and that did start to dump the fuel out and I also tested that when a vacuum was applied to the petcock the fuel also flowed out.  So I brought everything home and let it sit overnight and the next morning everything was still dry, a success!

Really it is kind of frustrating that I missed the alignment and the vacuum vent hole thing in the first place but I do have a complete understanding of how the petcock on Oldbike works now and when I go back to the original purpose of the project, to learn about working on bikes I guess even a mistake is not a bad thing.

I did replace all the vacuum tubes, overflow tubes and fuel supply tubes before I re-installed the carbs.

After I got the carbs back in I made a quick video detailing some of the things that I had learned as I have been taking the carbs out and putting them back in over the last nearly two years.  Maybe someone might find it useful.  You can check that out below!

Now that Oldbike is back on the road I started to identify little things that you wouldn’t notice unless you are riding the bike I will go through some of those things in the next post and one unexpected thing too.  I think that riding an old bike that hasn’t been run for a long time you will probably always find something wrong after each ride for at least a couple of years after getting it going again.

Thanks to all who are reading!  You can expect another update within the week!

Epic Fail on Fuel Tank Petcock Rebuild

This update has a number of YouTube clips that basically detail what I found after coming home from the Easter weekend away directly after rebuilding the fuel tank petcock which I covered in my previous blog.  When I came home and got out of the car in the garage the first thing that I noticed was that the garage smelled like gasoline (not a good sign).  Upon further inspection I found that there was a slow leak from the petcock down various components to the floor.  The first video is a (somewhat tongue in cheek) word of warning on petcock rebuilds.

The best advice I can give you regarding rebuilding your petcock is to not assume that just because you put all new parts in that everything will be fixed.  That is the mistake I made the first thing that I did after rebuilding my bikes petcock is take it for a spin and then fill the gas tank.  THIS IS A BAD IDEA! You definitely want to make sure that the petcock is functioning properly before you do such a thing.  The next most important piece of advice I have if you do what I did and fill the gas tank and have a petcock that is letting fuel flow freelyor if you just find out that you have a leaky petcock for the first time; is to bite the bullet and empty the gas tank rather than try to remove the gas tank and tilt is perfectly so that the gas is not spewing out the lid or out of the petcock to do your work.

Yes, you still have a little spillage when you put the drain tube on the fuel fitting of the petcock but the mess will be much smaller.

It’s pretty easy to see what I did in the above picture but to detail it out, I set up a 2.5 gallon gas tank (an important note is that the 1979 GS 425L gas tank does not hold only 2.5 gallons the full capacity is 3.7 gallons so plan ahead with two containers or on that will hole the entire contents) on a 5 gallon bucket on the right side of the bike so that when I rant the drain tube to the petcock that it wouldn’t have to make any hard turns.  You can see a closer look below.

After spending some time letting the problem marinate I let decided that the only thing that I did not change when I rebuilt the carb was the spring and decided that it must have weakened over the last 32 years.

I talked to some of the old codgers at Motorcycle Performance who suggested that remove the petcock, take it apart again, use an eraser to burnish the contact points and the valve nipple, and stretch the spring that pressing the valve nipple into the contact point.  Which I did, after doing the work, I had to figure out a way to do test the work I did without re-filling the tank and making a huge mess in the process.  In the video below you can see what I came up with.

I put about a quarter of a gallon into the tank and set the petcock to reserve to allow flow from the lowest point in the tank results follow in the video below.

FAIL!  As you saw that did not go well.  True it isn’t spewing out as bad as it was before but that was about but that was with a quarter gallon in it if you think about adding another 3.45 gallons into it the amount of force being put on the valve with the added weight of the gas could have had it spewing out just as badly.  I decided to leave that sit and look into why the gas was coming out of the float bowl overfill tube on the left carb when the carb float should be shutting the gas flow off.

That meant taking the carbs out again, so off they came!

I basically run down the findings in the video below.  The surprise finding was that the o-ring between the spacer and the carb boot was sheared in a section, if I’m honest due to me being lazy and not fully removing the carbs before installing the gaskets and when I slid the spacers back into place the tight fit cut the gasket into two places.

When I took the spare set of carbs apart I found some interesting things, see below.

After getting the good float’s height set I basically put the carbs together and that was it for the day.  I needed to find a source for some intake boot seals and find a cure for the issues with my petcock before I could move forward.

Check back to see if I have any luck!  More to come soon!