fujioko
fujioko HalfDork
5/10/15 2:33 p.m.

I found this little thumper about ten summers ago. It had been ridden hard and put away wet. The magneto and flywheel were missing as well as all the plastics and seat. I almost didn't stop, but I have a soft spot for little Hondas. A quick check of the motor ID revealed this was a not a cookie cutter XR80 but a more desirable XR75.

Old Honda's are always worth more in parts than whole. This roached out bike had enough wrong with it that it was better off going to the slaughterhouse. The art making profit is to quickly and efficiently carve up the carcass and not to get involved with a project. Sometimes I break the rules and keep one for myself.

The missing parts were sourced from inventory and the frame and tank got a re-spray. The original color is R-23 Tahitian red, but in my little podunk town that paint code was as useless as the 'X' in Grand prix. Fortunately, Tahitian red translates to ‘69 dodge R4.

Once finished, the bike was used and abused, as all Hondas should. Years of faithful service including rain, snow, ice and nighttime riding took its toll and the bike was pushed aside and forgotten. Its been over four years since the bike last ran and I'm feeling like its time to get it going again.

the party is over...... after years of fun the engine fell silent and little Honda was temporarily forgotten

Things are not what they seem. What appears to be a dusty but well sorted vintage honda is actually a collection of carefully selected misfit parts. To the casual observer, nothing seems out of place, however on closer inspection... there is nothing short of chaos. We are look'n at two generations of XR, XL and I even dipped into the 70cc gene pool.

Bonding with the Honda ...again.

New exhausts are spendy, this exhaust was custom made from Yamaha bits and mystery metal. The system was tuned for sound and not performance.... which I guess is typical for the Honda crowd

Mouse poop in the air box... but no nest? I have mixed feelings about this...Why would a mouse just take a crap and not build a condo? If I were a mouse, this Honda would be my crib... I would be like 'yo , get off my lawn....'. berkeleying mice don't know E36 M3.

A quick dusting of Armor All is the lazy way of making the bike look good.

Next up is the ignition....

914Driver
914Driver MegaDork
5/11/15 6:25 a.m.

Looks good. Is there an easy way to clean up between the fins besides plain old labor? I can never get a uniform finish.

fujioko
fujioko HalfDork
5/11/15 12:13 p.m.
914Driver wrote: Looks good. Is there an easy way to clean up between the fins besides plain old labor? I can never get a uniform finish.

Thanks!

I use a fine steel wire wheel and WD40 to clean the fins when I assemble an engine. Nothing really can clean aluminum without some scrubbing. Once the engine is clean, it can be kept clean with WD40/Armor all between washings. The WD40 and Armor all will collect dust and whatnot but makes washing the bike a snap.

The paint on this bike is ten years old and has always been dusted with Armor all after the bike has been washed. Seems to work for me, your results may vary.

fujioko
fujioko HalfDork
5/11/15 7:41 p.m.

The last time this bike ran was when the neighbor kid borrowed it. He returned a few hours latter with tails of woe... I think the trouble was the engine would start and then stall...or something like that. Whatever the problem, it didn't seem serious. My memory is pretty fuzzy, but I recall the problem had something to do with the ignition. Lets take a look....

This bike has the points under the flywheel. This was typical of a lot of older bikes. Servicing the points requires a special Honda tool, but first the flywheel nut needs to come off. The flywheel nut spins counter clockwise (lefty loosy Brrrr-rat-tat-tat-tat-tat! with the impact gun and the flywheel nut is off.

The flywheel removal tool installs by spinning it counter clockwise. It's a bit of a mind berkeley to spin something backwards to install it. its a good idea to thread the tool in as far as you can.

Brrrr- rat-tat-tat-tat-tat.... Brrrr- rat-tat-tat-tat-tat.... Brrrr- rat-tat-tat-tat-tat.... E36 M3, sometimes the flywheel can be a bi*ch.

Plan 'B'...Hold flywheel and strike the wrench a few times........ Nope.

Plan 'C'... give the center thingy a few taps. Its important to never hit the flywheel directly. Hitting the flywheel will crack or dislodge the magnets and certain doom will result.

Sucess!

The points are blackened and have oil on the surface. This is puzzling, I don't recall this bike having an oil leak. Shrugs shoulders...I don't know, but it ain't right.

New points installed. On an XR75, the condenser is mounted on the ignition coil. I also added a secondary magneto to power the headlight.

This is the inside of the flywheel. This gizmo here is what advances the ignition... the center is the cam that opens and closes the points....looks pretty crappy and will need a buff.

All cleaned up and ready to put back together.

Next up is the carburetor...

fujioko
fujioko HalfDork
5/12/15 9:15 p.m.

The bike was in storage long enough that the carburetor needed a quick inspection. This carb was rebuilt at some point so it shouldn't need more than a quick cleaning...

Let's take a look...

Not bad, but not good. Looks like slight moisture damage.

A little bit of crud at the bottom of the float chamber.

One of the jets had some junk in it.....

To clean the jet I use a bicycle cable and peel off a strand then poke around until the jet clears.

Reassemby...Put a bit of oil on the 'O' ring.

some more oil around the flange 'O' ring.

Carb back on!

The oil had a heavy gasoline smell... plus it was time for a change.

Pour in some fresh liquid dinosaur E36 M3.

Add some fresh gas.....then spun the engine over with the power drill and it started right up.

The engine runs great and a quick test ride is in order. As I recall the clutch is way past its time and that will probably be next.

Beagle
Beagle New Reader
5/13/15 8:12 a.m.

huh... I don't remember the XR having a charging coil. I know the SL's and XL's did, but don't remember it on the XR.

Neat bike! First bike I rode with a manual clutch. Good times!

tjbell
tjbell Reader
5/13/15 9:08 a.m.

keep it up! I love seeing the restoration of old honda bikes, I had an old XR100 i learned to ride on many moons ago. wish I kept it and could do this

fujioko
fujioko HalfDork
5/13/15 12:53 p.m.

In reply to Beagle:

The bike is a lovable mutt

The charging coil is from my respectable Honda stash, I believe it is from an XL70. The rest of the ignition, including the flywheel is XR80.

A quick rundown on other parts

SL70 wheels

SL70 fork tubes

K0 XR75 front fender

XL75 headlight

XL80 headlight bracket

SL70 handle bar

XL70 brake and clutch controls

XR80? throttle

Blue seat is possibly a 83-85 XR80

Exhaust is Honda+Yamaha+ custom

Even though the parts come from different bikes they are more or less interchangeable. sometimes the only difference is chrome or paint.

Frame, fuel tank and most of the engine are original 1977 Honda XR75.....I think

In reply to tjbell:
These old thumpers are addicting, all it takes is one bike... you know what I'm talking about

tjbell
tjbell Reader
5/13/15 1:23 p.m.

I have been on the look out for an older xr/xl 650 to restore and make a fun dual purpose toy

fujioko
fujioko HalfDork
5/17/15 8:57 a.m.

The little Honda was temporally reassembled for performance evaluation....The bike runs great! The only disappointment is the clutch is rather weak and slips massively at full throttle. I could live with this for another year or two but this time I'll do it right.

Replacing the clutch requires the footpeg and kick stand assembly be removed and the bike has to lean up against a wall or something... this is fine, but I discovered an engine stand is available for about a hundy and it makes working on the engine mucho easier. Being a GRM project, I ain't going to peel off a stack of Jacksons for something I can make in an hour or so...
Lets look at some pictures..

Located the required 'junk' for this project.
Motor mounts are from my stash, dowels were machined from some scrap that was near the lathe.
looks like the mount needs to go here...
Quick visit to the drill press...
[/URL]Dowels slid in...
Bzzzzap...
Some more welding and we arrive here. A dummy engine was mounted to check fit. Next a stabilizer leg is added.
Bzzzzap!
Done!...well almost... needs paint.

next up is the clutch..

fujioko
fujioko HalfDork
5/30/15 6:27 p.m.

Alright, project creep...it was bound to happen.

Anyway, the clutch repair has been postponed once again.

In a dark corner of my basement two unfinished bikes sit dormant. I seem to recall both bikes have rebuilt engines, however I don't know exactly what was rebuilt. Forgive my apparent stupidity but I've had a dozen or so of these bikes and its all a blur...

So....

One of the basement motors mounted on the engine stand. Originally I was going to paint the stand blue, but a red stand makes the motor seem moar powerful. A fuel tank and genuine twist throttle makes this rig so cool it also qualifies as furniture for the man cave.

other than a squirt of oil, I didn't bother doing any preflight checks. The engine started right up.

The engine ran really good and was phenomenally quiet... Good enough! A few moment latter the engine was off the stand and ......

.... the engine came off the bike. the swap was finished in record time.

A quick test ride confirmed the basement engine was indeed a winner. The clutch feels great and now I can do the clutch repair on the original engine without any downtime.

Next up... the clutch.... I mean it this time.

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