Project Honda XL250s 1979

Thanks, I've read that. Have bought the LED light and will see how it goes when it arrives.

 

Today I fitted up the LED light and fired up the engine. With the headlight (6volt system) in place and the LED added to the wiring it flickers badly and would be unusable (this is direct AC from alternator). The voltage was only 7.4 at high revs with bulb in place and 15.7 without bulb, so when I connected that to the LED it promptly blew something and it no longer works (even on 12 volt battery). I put the standard bulb back in and it blew too, so I don't know what has happened there. Ran out of time to check any further.
My question today is how to wire up the bridge rectifier from a single wire from the coil? Do I just use the one wire to one of the AC terminals, run a bridging wire to both terminals or do I have the wrong type for a single wire?

 

Thanks my67xr, but if I use the rectifier then it will be DC and have no flickering anyway. Will have to get a Zener diode to stop the power spikes and a bit of tricky wiring to run straight from the alternator to LED, and the standard wiring to headlight.

 

Have the new replacement light and a voltage step up box (6v to 12v) fitted up and working. Does flicker a little at idle (but I will not be riding at idle at night) but once over about 1500rpm it is smooth and steady. Will go out one night and see just how good it is. For now is very bright in shed compared to headlight.
Headlight high beam.

LED.

Step up box, light and bridge rectifier.

 

My old XL has been going great the last couple of years but the blinkers have now started going very fast, so fast it is hard to tell they are flashing. I have replaced the flasher can three times with different types, no difference. I have tried upping the wattage of the bulbs from standard 10watt to 18watt with no difference in the flashing rate, just a bit duller. I have fitted a voltmeter and the volts sit at a steady 7.2 when riding, I even left the lights on to flatten the battery down to 5.5volts one afternoon and they still flash too fast. All wiring and switch gear is clean and standard as it left the factory.
Any ideas why this is happening?

 

On my last ride the battery went flat and had no blinkers or stop lights by the time I got home. I soldered two wires to a 12 volt headlight bulb and started the engine, and using the wire found no current coming from the magneto to the charging rectifier. I had replaced the rectifier two months ago, after the original 45 year old one failed, with a modern mosfet type but now had no power to it. I removed the engine sidecover and found the coil for battery charging looking rather crispy. I replaced the coils with one from a spare engine and now all is good again, even the blinkers have slowed down, so I don't know what is going on there.
Small coil at top of picture.

 

It has taken 45 years for this old XL to clock up 20,000Km, so time for a service. I had noticed last week when I had the left sidecover off that the balance chain was a little loose, so while the oil was draining I lifted the right sidecover and gave it a tighten. Even the pickup screen was clear, so it must be running nicely.

The kickstart seal has been having a little dribble so I lifted it from the case. The lips were in good condition so I removed and shortened the spring in back of the seal to give a slightly tighter fit to the shaft. Replaced the spring back in the seal and fitted to the case.


Ready for the next ride.

 

My old XL has been getting slower and harder to start lately, and has picked up an (oil) drinking habit. I decided that while I had the tools out after doing a rebuild on a friends XL that I put mine on the bench and did the same.
Head has bad carbon build up and bore worn, so new oversize piston and a rebore coming up. I started with the head. Valves very heavily carboned up and the ports no better. While I had it apart, I couldn't help myself and got the Dremel to clean up all the casting 'dags' in the ports.

A blast clean up, very light touch to the seats and valves brought them back to specs, a diamond lap and check with bearing blue. All good.

The carb mounting rubber had seen better days so while waiting for the machinist to do his magic I cut the old rubber off the alloy mounting, tuned up short piece of tube to match an intake rubber from an XLV600 and welded together. This will sit the carb back about 5mm from the head and will help the shrunken intake tube to airbox seal better.

And then matched to the intake port of head.

Hopefully this rebuild will stop those who ride behind me complaining of the burnt oil smell.

 

Got my barrel back from the reborer (finally) and gave it a hot soapy wash and wipe with oil. Fitted the engine back together and when I get some help to get the bike off the bench will be out to do more adventure rides.

 

Engine running good and quiet, pulls much better up hills too. Out for ride with friends tomorrow so there should be no remarks about the destroyer laying down a smoke screen.