Yamaha RX?125

[meowmix]

Hey,
My old man has an old RX (maybe) 125 in the shed. Its in a pretty rough state, but fairly serviceable. I'm planning on getting it bucketworthy (read: running) and I'm after some advice.
Its prob somewhere, but I'm useless at searching.

The things got no electrical system to speak of. We are basically running the generator lead from the points to the coil with no luck. Testing the voltage is difficult with a slow digital multimeter, but we did get one of about 150 volts whil kicking.
We did get it going with a 12v battery hooked up to a car coil, just using the points as the switch so it can mechanically run.

I guess the main thing to ask here is: Can the coil be powered straight from the generator/points as it currently is?
If so, what would be the best coil to use? Assuming thats the problem.

Again, sorry if the info is right in front of me, I have only recently discovered Buckets, let alone the screeds of threads about them.

Cheers!

P.S. If there is a tank lying around somewhere, I may be interested. The current one looks like someone filled it up with saltwater.

[F5 Dave]

Search is easy. Hit that button up & to the right a bit & type in RX125.

Will need a battery.

[Muzzab]

Search is easy. Hit that button up & to the right a bit & type in RX125.

Will need a battery.

I profess to have no mechanical ability what so ever, but have an RX125 running on points and coil, with no battery. Is it a miracle that it goes?:whistle:

[meowmix]

I profess to have no mechanical ability what so ever, but have an RX125 running on points and coil, with no battery. Is it a miracle that it goes?:whistle:

I was sure it would go fine with points also. Cheers. Looks like I'm up for a new coil.

[F5 Dave]

Sorry brain off, yes unless you go total loss then will need battery, but totally right. Ahh heck I haven't had a bike with points for like 20 + years:pinch:

[all4A50s]

I profess to have no mechanical ability what so ever, but have an RX125 running on points and coil, with no battery. Is it a miracle that it goes?:whistle:

I run a RX125 engine on mine. I run with no battery without difficulty. Early on in the season I had no spark. I managed to clean up the points and ended up buying a condenser from Repco, which I mounted up by the coil and bike hasn't missed a beat since.

[Muzzab]

I run a RX125 engine on mine. I run with no battery without difficulty. Early on in the season I had no spark. I managed to clean up the points and ended up buying a condenser from Repco, which I mounted up by the coil and bike hasn't missed a beat since.

I had coil trouble with mine too. I had a spare coil which works fine, but as it was nearly 30 years old brought a new one. It came with a condenser attached, the guy at the bike shop said to cut the wire to the condenser, as there is one in the bike. But the bike would not run with the new coil. So I put the old spare back in. I talked to one of the guys at the track and he told me that the coil and condenser needed to match. I intend to fix the wire on the new coil and condenser, and give it another try after removing the condenser on the bike. Hopefully it should work.

[meowmix]

Interesting stuff. I assumed you could just mix any coil + condenser.
I'm interested in how your works out, as there is a fair bit of arcing across the points (or there was with the external power source).
What type of coil would be best for a batteryless bike? Any 6v type?

[Muzzab]

Interesting stuff. I assumed you could just mix any coil + condenser.
I'm interested in how your works out, as there is a fair bit of arcing across the points (or there was with the external power source).
What type of coil would be best for a batteryless bike? Any 6v type?

I might have a try on the weekend, I'll let you know if it works. As for coils I never gave it a lot of thought, just asked at the bike shop for one to suit a RX125. Was a bit miffed when it didn't work though.

[TZ350]

.

Its a bit wordy but has some interesting ideas on getting ignitions going and lights if you need them. http://www.btinternet.com/~jhpart/bkns125a.htm

.

[Muzzab]

Had a look last night, although I could see the condenser I can't get it out without taking the fly wheel off. Don't have a puller (yet), so won't be tinkering with it in the short term. Cheers Muzza