Another Gem - 1978 Honda XL 75

[coolpool]

Went to a friends about 1 1/2 hrs away to work on my jeep transmission and noticed a bike leaning against a spruce tree in his yard. Turns out it's a 1978 XL 75 with only ~2000 kms (1200 mi) on the clock. He told me it's a friends and tinkered with it a bit but couldn't get it going. Ironically, he doesn't hesitate to split a tractor for a clutch but really doesn't like to work on this sort of thing. It didn't look too promising at first covered in sap and grime with the seat pan growing into the tree bark as it's been there so long. I confirmed the piston moved, and seen old gas still in the tank so potentially intact. Looks fairly complete, seems to shift OK but but unfortunately missing all signal lights and both side covers are broken. I did find the original owners manual in a pouch inside one panel which is a bonus. I filled the cylinder with marvel mystery oil as a precaution and drained the motor oil which had a teaspoon of water in it and grossly overfilled. The best part is I paid $100.00 for it and can potentially register it for the road at some point.

What it needs initially at this point:
2 tires
Header pipe is corroded through in one area - easy welding fix
Check for spark
Check compression
Clean carb
Needs a chain and maybe sprockets - cut off the old chain as it was seized solid and piano spring tight
Hand grips
Throttle handle
All cables
Seat pan needs patches but still serviceable
Seat foam and cover

This is going to be a slow resurrection as it's getting into outdoor activities now and shop time limited to rainy days.

[El Camexican]

The go to bike for dads that didn’t want their kids learning to ride on RM/KX/CR/YZ 80’s. You’re gonna hear a lot of “I had one of those” at the annual parade.

That over-tightened chain is period correct as it was typically the first suspended bike for most, so they tightened the chain like they would on a Bronco, or a bicycle

[coolpool]

Started tinkering a little starting with the carb, yikes......nasty inside! I managed to get everything freed up and blown out so I'm expecting at least marginal success before I pop for a rebuild kit pending the bike is worth the effort. Good news is that there's an oily (albeit disintegrating) foam filter element in it which makes me feel better.

Now on to spark. Question, this unit uses a small battery.......do I need a battery for it to produce spark? I'm guessing not as most ATV's I've dealt with can be kicked/pull started when the battery is completely dead as long as it's carbureted. Please advise if this isn't the case as I'm not at all experienced on bikes.

[ATC King]

It shouldn't need the battery to start.

Those early Honda XL's just had a battery for the street legal bits. They had to have a battery powered rear light by law that way if it was on the side of the road and not running the rear light still worked.

The battery was also for the turn signals, instrument lamps, and horn. The headlight should still be AC, which only works with the engine running.

I haven't had one that vintage, but what I said is pretty much par for the course on US model XL's. Ignition and headlight operate on AC, the rest is DC.

It probably has 6v battery/system. You can upgrade that to 12v for modern compatibility.

[coolpool]

^That definitely all makes perfect sense ATC, thanks for this! I wouldn't expect Canadian models to be set up any differently either. I was told it had spark by the guy who sold it but you know how that goes.......by the look of the flywheel area I'm guessing no. I'll pull it and clean/adjust the points and see what happens.

Cheers,

[ATC King]

Out of curiosity I checked Partzilla to see if it had points...yep.

The points and condenser (capacitor in new terms) are still available new through Honda but that's about $50.

The six volt battery isn't saving any money over a twelve volt one either.

Depending on your plans and budget it may be better to convert the system to twelve volts and install an electronic ignition. The bolt-on iggys I found for it can get pretty expensive though. Of course, since you only paid $100 for it, basically anything it needs is going to blow the purchase price out of the water. Would be a good idea to get it running and sorted out then go from there.

That'd make a great RV bike for toodling around the camp.

I know I'd replace or remove the front brake shoes before riding it any. Something that's sat that long has a pretty good chance of the brake lining delaminating and locking the front wheel. Front drum brakes have other issues besides stopping power.

[coolpool]

Definitely going to take small steps to see if it's viable to get this back to road worthy condition. I've been informed by the boss that this is going to be sold so I'm thinking parts wise I need to keep it below $1500. I'm not concerned about labor costs as It's my hobby. It will be gone through front to back and will take your advice to heart.....thanks :-)

[coolpool]

Update: It was pretty simple to get spark, found a broken ground wire and cleaned/adjusted the points. When checking valve adjustments, it appears to me that someone has been in this thing as why else would there be assembly lube on the valves and on the end of the cam shaft? I hooked up a temporary fuel source and spun the heck out of it with a drill/socket on the flywheel to see if it will fire. I got a couple of inconsistent pops back through the carb. I'm wondering if it's 180 degrees out? The best I can get for compression is ~75lbs even with the cylinder warmed up with a heat gun and wot. Think I'll pull the stator plate and check valve timing next then pull the jug to check the piston/cylinder clearances.

Note: I also pulled the exhaust off to make sure it was clear and I tried to get it to make noise with the exhaust off completely.

[shortline10]

Flip the flywheel over and make sure the advancer dots line up . Very common for them to be installed 180 degrees out .

[coolpool]

^I'll have to look into that as I've never encountered such a thing. I suspect the information is in my manual.....hopefully :-)

[ATC King]

You may want to check out BAT if you haven't recently.

The smaller XL/XR bikes are bringing relatively high prices. Not that you're building it to sell but if you work around a budget it may be an option if you decide to.