88jog
Scoot Junior
Posts: 11
|
Post by 88jog on Jul 5, 2018 14:16:33 GMT -5
I understand mechancals pretty well, but things get a little foggy when I start dealing with electrical systems.
Is there a good walkthrhough on how to do a complete DC conversion using the stock stator? I get the impression that basically the grounding system needs to be reconfigured, and a diode and capacitor needs to be added on the positive side to prevent backfeeding of excessive voltage.
|
|
88jog
Scoot Junior
Posts: 11
|
Post by 88jog on Jul 5, 2018 13:43:46 GMT -5
My Jog has burnt out high beams, resulting from a failed voltage regulator. I have replaced the regulator/rectifier, but I still have to deal with trying to find a replacement sealed beam headlight for a 30 year old scooter. Even when working the headlight kind of sucks. And considering a new headlight is expensive, I can get a new LED headlight assembly and rectifier for less than a Yamaha unit. Problem is, LED's are DC, and the headlight on a Jog runs on regulated AC direct from the regulator/rectifier. Two questions. Can I run a second stand alone rectifier right at the headlight to convert to DC? Also, what sort of wattage headlight can I run without stressing the charging system? I know it's possible to convert the entire system to DC, but I'd rather not do all that rewiring if I can just add a small box in the headlight fairing. The objective is to end up using something like this: www.amazon.com/Rectangular-Headlight-Replacement-T001N-4pcs-Colight/dp/B07BRZ5J69/
|
|
88jog
Scoot Junior
Posts: 11
|
Post by 88jog on Jul 5, 2018 13:32:19 GMT -5
I have the same scooter, and my petcock leaks slightly as well but I dont have the starting problems you do.
Did you find a rebuild kit for the petcock? I see I can buy an entire assembly on amazon for about 40$.
Maybe I'll just replace the little oring and put a slightly stronger spring. The diaphragm still seems ok without any holes. Not quite sure why it's leaking actually. I get a drip off the bottom of the carb about once every 10 minutes.
|
|
88jog
Scoot Junior
Posts: 11
|
Post by 88jog on Jun 17, 2018 15:01:08 GMT -5
I'm in the Madison Wisconsin area, which is fortunate because it's a college town with a large campus and about 45,000 students. Scooters everywhere. But this scooter is old enough that I'm having a lot of trouble, even at the two salvage yards.
A few other parts I need, in case someone sees this.
* Center stand. This seems to be just about unobtainable.
* Headlight. My high beam is burnt out. It's a stupid sealed beam unit, and I refuse to pay over $100 for a NOS unit. Is there a high beam relay or could the switch be bad? I suppose some work with a multimeter is in order.
* Fairing pieces. They are sort of cobbled together now with rivet repairs and such. 30 year old plastic is just not strong anymore.
* Front fork. The current one works, but it was straightened after crash damage, and is still slightly wonky.
* Disc brake conversion. I'd love to find a European spec front end, or something that's compatible that would let me run a front disc brake. The scooter has been modified enough that it now does 43mph and the brakes are lacking.
|
|
88jog
Scoot Junior
Posts: 11
|
Post by 88jog on Jun 17, 2018 14:12:31 GMT -5
UPDATE:
Well, it turns out that the speedo DID break in exactly the right way that made it display kph. I actually tested the odometer, and it was properly clocking miles. I opened it up and sure enough the clock spring was corroded, and since rust doesn't spring like steel does, the spring was weak and allowing the needle to turn farther than it should.
Now I just need to track down some sort of replacement unit.
Can anyone recommend a slick aftermarket unit that displays speed, odo, turn signal, fuel, high beams, and oil?
|
|
88jog
Scoot Junior
Posts: 11
|
Post by 88jog on Jun 17, 2018 0:06:50 GMT -5
I'm thinking maybe I need to crack open the speedo. It works when the scooter is off and I spin the front wheel by hand. I'm thinking its the magnetic type. Maybe theres something in there that is causing the needle wheel to spin faster than it should. Maybe the magnet is too closee to the aluminum pickup or something. Or a cobweb causing drag. There's also a spring that works against the magnet rotation and returns the needle towards 0. If that spring is weak, it would cause a higher indicated speed.
|
|
88jog
Scoot Junior
Posts: 11
|
Post by 88jog on Jun 16, 2018 22:19:19 GMT -5
I had a local shop look up the speedo gears. 14 tooth and 8 tooth are correct. I can understand if a tire change altered the indicated speed by 10%, but not by a factor of 1.6. Plus, if the tires were oversized, the indicated speed would be lower than actual, not faster.
|
|
88jog
Scoot Junior
Posts: 11
|
Post by 88jog on Jun 16, 2018 21:44:10 GMT -5
When I was using the scooter in college it did not have this problem. But this problem has been around for quite a while. To the best of my memory, it was probably since the rebuild that the speedo has been misbehaving. The reason I'd like to fix it is that I'm fixing the scooter up for my nephew to use in school, and would like to get everything operating properly.
|
|
88jog
Scoot Junior
Posts: 11
|
Post by 88jog on Jun 16, 2018 20:48:39 GMT -5
I have 1988 Yamaha Jog cg50. It's has the typical speedometer that was on all Jogs and Razz's of the time period. It has an inner half circle of numbers that show kph, and an outer half circle of larger numbers that show mph. For some reason, my speedo indicates kph on the outer ring of numbers. So if I'm going 20mph (verified with GPS) the speedo says I'm doing ~32mph. And if I'm topped out at 43mph, the speedo needle is bottomed out against the bottom edge of the instrument cluster.
I thought that maybe someone had changed the speedo drive gears in the front wheel hub, so I went to a salvage yard and got a different set. I opened up the hub and got ready to put them in, only to discover that the new gears were exactly the same as the old ones. The large plastic gear is 14 teeth, and the small metal gear that the cable plugs into is 8 teeth.
I did repair damage from a crash about 20 years ago, but the instrument cluster is original. I guess it's a possibility that the speedo is faulty, but I have a hard time believing that it broke in such a way that it is perfectly functional, only that it now shows kph.
What the heck is going on?
|
|
88jog
Scoot Junior
Posts: 11
|
Post by 88jog on Dec 5, 2017 15:51:38 GMT -5
Its got to be something like this.
Although I havent actually tested to see if the odometer is accurate. If it is, it means the speedo is actually faulty. That will be next on the list.
Thinking about it I cant imagine that they have different gearings for kph and mph. They would just change the display on the speedo. But then they would need different gears inside the speedo to keep the odometer accurate. So they either do it at the hub or in the speedo but not both.
|
|
88jog
Scoot Junior
Posts: 11
|
Post by 88jog on Dec 4, 2017 21:24:46 GMT -5
So, a little background first.
I have a 1988 Yamaha Jog CG50. I got it in 1999 and used it in college. It's a US model so the speedometer display is calibrated in MPH. About a year later I let someone drive it and they managed to crash, so I rebuilt it. My memory is a little hazy, but I replaced the speedo cable and/or replaced the front wheel with items purchased on ebay and scrap yards.
I recently got the urge to get it running after about 10 years of storage, and managed to do so pretty easily. But I realized that the speedometer needle is actually pointing to kph on the mph scale. In other words, if I'm driving at 20 mph the speedo needle would be pointing to 32 mph which is how fast I'm actually going in kph. If I move at top speed (variator shim removed, 43 mph by GPS) the needle is bottomed out at the bottom of the speedo.
This is annoying, and I'd like to fix it the easiest way possible. It also adds extra miles to the odometer every time I drive it.
Can someone tell me how I screwed up when I rebuilt the scoot, and what the cheapest/easiest way to fix the issue would be?
I'm assuming something is messed up with the speedo gearing in the wheel hub. Maybe I put a kph wheel on a mph scoot if I replaced the wheel? I dont think I replaced the wheel though, it appears to still have the original white rims on it which I repainted flat black (looks badass). I know I bought a pair of purple wheels from a 90's model CY50 Jog on ebay, which I only used for the tires, as the purple wheels are still in the shed. Maybe I moved the speedo gear from the purple wheels to the original wheels? Would it be possible to mess this up with just the speedo cable which I think I purchased at a scooter salvage yard or possibly ebay as well?
Also, I'm in the process of tuning the carb for a pod filter, and have to increase the main jet size. I managed to find a 77.5 locally, but I don't know what the factory main jet is for a starting point as it is unmarked. Anyone know what the factory jet size is?
Thanks, and if possible part numbers for the speedo fix would be useful.
|
|