• Welcome to the Two Wheeled Texans community! Feel free to hang out and lurk as long as you like. However, we would like to encourage you to register so that you can join the community and use the numerous features on the site. After registering, don't forget to post up an introduction!

1970 SL100

Joined
Apr 18, 2007
Messages
5,738
Reaction score
152
Location
Salado
Well, after an inordinately long delay, I'm getting started on the project. Here is my preliminary survey of the bike. Most of the delay was spent collecting reasonably priced parts to actually start the projet. I didn't want to have it sitting around while I looked for a $2 widgit that's NLA.

Picture002.jpg


Picture016.jpg

It's in sad shape--missing lots of hardware, but surprisingly it has the original key and it fits the ignition (which is cut ouf the circuit) and steering stem lock.

It had the wrong fenders, fore and aft, and that didn''t matter since they were broke anyway.

No headlight, taillight, or speedo. Wrong grips (they're trash anyway), left switchgear is missing and right switchgear is broken, and the throttle doesn't seemm to work. It's missing the tool bracket, part of the air cleaner and what's left of that is trashed too.

I've collected the following NOS parts:

Levers and hardware
speedo
speedo mount bracket and hardware
speedo cable
a bunch of misc nuts, bolts and washers
air tube
top bridge
grips
footpegs
fork tubes and innards
swingarm bushings

Picture020.jpg


Picture019.jpg

The wiring loom is cut to pieces, but I've found a good used one for $20. I think I'm going to replace this coil along with the condenser and points and spark advancer. All NOS and readily available fairly inexpensively.

Picture022.jpg


Picture021.jpg

Both rims are wrong--4.00 X 18 back and 2.75 X 21 front instead of 3.25 X 17 back and 2,75X 19 front. There was like 1/4"clearance between the back wheel and swingarm. I've found good used rims and will polish them up and respoke then with the NOS spokes I've found.

Dunlop doesn't make the original tires, but I've found a set of Chinese knockoffs that look a lot like the original tires.

Picture014.jpg

I'll replace the sprocket and countershaft sprocket and chain along with the hardware that holds it in place.

Picture010.jpg


Picture011.jpg

both forks leak and the fork tubes are rusty and pitted. I have found one complete tube including spring, circlip, seal and bottom piece. Still looking for another or the parts individually.

Picture006.jpg

Both shocks are shot--new ones are available in Thailand for <$100

Picture004.jpg

Did I say the grips are bad? Wrong bars too and I haven't found a set of the original unbraced type yet.

Picture005.jpg

The seat cover is bad, but it's better than the seat pan.

Picture007.jpg

This is trash.

Picture012.jpg

It has an oil leak at the head, which doesn't really matter much because I'm going to take the head off and check the piston, rings, cam, cam sprocket, and cam chain. The parts are so cheap it doesn't make any sense to put it back together with iffy engine parts.

Picture003.jpg
It has a funky aftermarket pipe on it. I wonder if it's worth anything? It can't be worth what I paid for a NOS muffler and heat shield. They are HARD to find.

Picture015.jpg


Picture026.jpg

The paint on the tank is about 1/16 of an inch thick, but that doesn't matter since the inside is trash and its the wrong tank anyway. Its supposed to have the "Honda" emblem and not a decal. I've found another that is pristine inside, but has other issues I need to address.

I've collected a better tank, both side panels with all tabs, front and back fender, new air box, chain guard, NOS brake shoes, NOS muffler, NOS tail lightr bracket, NOS headlight, and a good seat.

My first job is to get it running. Stay tuned.
 
HOLY CRAP!

Let me say two things...

1. With everything you've listed, I'd have not even started the project. Sounds like you are keeping the frame and maybe some of the engine, and replacing everything else. Wow.

2. Can't wait to see it finished. The before and after shots should be fantastic!
 
I had the 1970 CL version as a teenager, and would like to have one to restore just for nostalgia. That was the first year of production - the K0 model.

I always considered the engine a testbed for the world's weakest ignition system. It took careful timing work to get it to make adequate RPM to make 50 mph. The brochure, which I have framed in my shop, lists the top speed as 66 mph. Maybe if it was dropped from a helicopter....

Keep us informed on the progress.
 
I had the 1970 CL version as a teenager, and would like to have one to restore just for nostalgia. That was the first year of production - the K0 model.

I always considered the engine a testbed for the world's weakest ignition system. It took careful timing work to get it to make adequate RPM to make 50 mph. The brochure, which I have framed in my shop, lists the top speed as 66 mph. Maybe if it was dropped from a helicopter....

Keep us informed on the progress.

My first real motorcycle was a saphire candy blue 1970 SL-100, purchased in April of 1970. I remember it as a pretty peppy bike and capable of 60 mph all day long. Of course I was 15 and weighed about a buck twenty. We had to have the restricted slide in the carb at that time to limit it to 5 BHP. Somewhere that first year the legislature chagned the law for 15 year olds from 5 BHP to 100 CCs and I was able to get the unrestricted slide and get the full 11.5 HP.

Most of my friends had a Suzuki/Yamaha/Honda/Bridgestone 90 or 100. The Yamaha DTs and Honda SLs were the most modern having a double cradle frame instead of the pressed steel frame most small bikes had at the time. I lusted after an SL350 and would like to find one for my next project.
 
HOLY CRAP!

Let me say two things...

1. With everything you've listed, I'd have not even started the project. Sounds like you are keeping the frame and maybe some of the engine, and replacing everything else. Wow.

2. Can't wait to see it finished. The before and after shots should be fantastic!

Hey, you gotta start somewhere!:mrgreen:
 
Well I had a 1970 SL100 as my second bike but first "full size" motorbike.
It had the small kick start shaft and snapped off in short order.... I totaled
that bike during a off road race in 1972. I bought another SL100 this time
a 73 model in green with yellow on the tank. Kick stater shaft was much
beefier on that model. I raced it also with Power Up kit and Basani exhaust.
I weighed about 130 and the bike would run 65mph all day log. Amazing....
I also have always wanted a SL350 K1. I found one rougher than your SL
and he wanted a $1000 firm and it would not start. Presently, on Austin
Craigslist is a partially restored SL350K1 with good pipes for $3200. Almost
asking more for this bike than some 3 or 4 year old XB12 Buell's. Also Amazing..
 
Well I had a 1970 SL100 as my second bike but first "full size" motorbike.
It had the small kick start shaft and snapped off in short order.... I totaled
that bike during a off road race in 1972. I bought another SL100 this time
a 73 model in green with yellow on the tank. Kick stater shaft was much
beefier on that model. I raced it also with Power Up kit and Basani exhaust.
I weighed about 130 and the bike would run 65mph all day log. Amazing....
I also have always wanted a SL350 K1. I found one rougher than your SL
and he wanted a $1000 firm and it would not start. Presently, on Austin
Craigslist is a partially restored SL350K1 with good pipes for $3200. Almost
asking more for this bike than some 3 or 4 year old XB12 Buell's. Also Amazing..

Yeah it is, I've been watching them on ebay and craigslist and you can find decent ones for $2000, but you have to go pick them up two states away. I'm collecting projects for retirement-I'd like a lot of the 1970s Hondas; CB450, CL350, CB750, SL175, CB550, and another CBX, maybe a '79 this time.
 
I had a pristine 79 Red CBX that I bought in 2005 for $5K, rode it for a year
and sold for $5K in 2006. It was beautiful but a hand full to keep running. Of
the bikes you want I have owned all but the CB450. They are out there, but
unless you do the rebuilding they are not cheap. Goto www.marblesmotors.com
 
I had a pristine 79 Red CBX that I bought in 2005 for $5K, rode it for a year
and sold for $5K in 2006. It was beautiful but a hand full to keep running. Of
the bikes you want I have owned all but the CB450. They are out there, but
unless you do the rebuilding they are not cheap. Goto www.marblesmotors.com

Randy Marbles found the NOS muffler that I have. After doing some research I think the bike I bought in April 1970 was between change over from 1970 to 1971. It was a 70, but didn't have the studs on the seat and the tools were in a box below the battery and it had metal "100"emblems on the side covers. All three were were K1 changes, but it was definitely titled a 1970. This bike has the K0 tool location on the right side of the frame but the seat had no studs.
 
I ordered a new coil, points, condenser and battery and hopefully will be able to give it a try in ten days or so. I think I'm going to just bodge the current wiring loom to get everything working before I strip it for refinishing.
 
Is there a restored SL in the Universe
Randy does not have a hand in? He is
the Vick World of Honda Motosports!!
Good luck on your project. I rode a
fully restored SL100 about 10 years
ago and it was a blast!! So light, agile.
 
bmcdonau,

I also had a brand new blue 1970 sl70 in 1970 (my first Honda) then a used green 71 sl100 back in 72 then got a another used green 71 sl125 about a year later, so I have a soft spot for these as well (rode the crap out of all of them but they never failed me).
Considering the prices for nice quality parts these days, I'm not so sure I'd go the full restored route maybe a vintage racer so you can still use exhaust, pegs, rims & stuff you already have. Just chasing down stock exhaust alone is a challenge that could kill a stock resto project. (and your looking at a lot more stuff that can also be hard to find items)

Don't know how far you have gotten yet - but I noticed you were watching a couple sl100's from ebay & craigslist stating that pricing was 2K+ and too far away.

But if your really wanting a stock looking/running model, see link below: It's a 71 (all the correct K1 stuff)

Saw this beauty the other day and its only a few hours drive from you (south of Houston) and probably cheaper than you will end up spending getting yours to same condition.

It's not mine and I don't know the owner, but it maybe worth a look for you.

http://houston.craigslist.org/mcy/2120142366.html



BTW - ever thought about selling your 74XL350? if so let me know - Now that was my all time favorite bike!
From back in the day - > My XL350
 
I have a project '71 blue SL125 , that I have working on for most of the last year. I now have the correct fenders, and all the sheet metal has been reworked and professionally painted. I powder-coated the frame, hubs, and a several other parts. Going to have about $4,000 in a nice $1,000 bike. My father used it as a motorhome bumper bike, and gave it to me before he passed away, so I rationalize the expense by calling it a "family heirloom". I plan to let the grandsons learn to ride it, if they can get me off of it.

Be cautious about ordering the parts from Tailand off of ebay. So far, about half of the ones that I bought were incorrect, and the shipping expense makes it impractical to return them for credit. I did get new rims and stainless spokes that came out very nice, but it took about 4 months to get them. The chrome headlight ring was not correct, and the rear shock adjuster seats were the wrong diameter. Will post some pics when I get finished.
 
wow that'd going to be a lot of work ,but I really love these enduro types from the 70's my first was a 90 cc. Suzuki that I bought for $90. By mowing yards. Rode the **** out of that thing till the motor went out then worked with my father at a farmers market during the summer to rebuild it that's when there was a Suzuki dealership at Samuel and Big town in Dallas. Was some of the best times of my youth.
 
It took me longer to get started again than I thought. I had to service the Wing, then the XL350 started running crappier than it was and I decided to reqally figure out what the problem was with it and that took all my garage time.

Picture027.jpg

The throttle tube moves, but the throttle cable seems siezed. I have a new cable, but no throttle tube so I hope my diagnosis is correct.

Picture028.jpg

the wiring is sliced and diced. I don't trust this coil and I have new replacement; condenser too.

Picture029.jpg

I'm going to try to get the ignition switch working too.

Picture030.jpg

These old bikes hade a selenium rectifier, there are better replacements available, but I happen to have an NOS Honda replacement so I'll use it. I have to put the new battery in because it won't start without a battery.

Picture031.jpg

I hope I can figure out where these go once I put the rebuilt harness back in. I mean physically, there are only a couple connectors so it shouldn't be hard to find out where they go electrically.

Picture032.jpg

I have a new Chinese carb so I don't know if I'll try to rebuild this one or not. It looks pretty bad.

Picture033.jpg

The new battery charging.

Picture037.jpg

Nothing like new parts to get you going. You can clean some up, but others need more than cleaning.
 
I spent a couple hours this afternoon working on the harness. It was a used ebay find, much better than the bike came with. It doesn't take much knowledge to put one of these together as long as you have the right tools which pretty much means a schematic and one of these.

Picture053.jpg


This harness is better than the nonexistent one on the bike, but it has issues too, several wires are broken, a few connectors are missing, the fuse is missing, and a couple wires appear to be gone too.

Picture039.jpg


Picture040.jpg


Picture041.jpg


The first thing I did was take off the plastic tube which protect the wires from chaffing at the steering stem. It's supposed to be soft and flexible, but it was harder than a rock.

Picture044.jpg


The positive battery terminal is missing.

Picture046.jpg


But those are easy to replace.

Picture047.jpg


This brown wire goes to the powers the tail light and needs splicing. This is the oldest bike I've worked on and I was surprised to see that the splices were all soldered. The newer bikes like by '83 CB1100 use brass crimps for the splices. The blue electrical tape below the colored tape on top (gray or black) is the same on the 70s and 80s Hondas I've worked on.

Picture050.jpg


I'm using these crimp splices instead of soldering them, they'll work fine.

Picture051-1.jpg


I had to repair four broken wires and replace a couple ring terminals. I still need to replace a couple bullet connectors (I'll have to order them) and replace the negative battery terminal wire. I'll look for some gray electrical tape tomorrow and see if I can find some type of plastic tubing.
 
Dump the OEM rectifier for the radio shack. I would box the new one and use the wires from the one on the bike for the Radio Shack upgrade. For $4 you will have a much better system and that really helps cause even new, these bikes had anemic electrical systems.
 
I thought about it, but I'm a stock kinda guy. This one has a light switch so I can turn it off when I ride.
 
Making progress today, I finished the harness, installed the new battery and new carb. I think next weekend I can change the oil, install a gas tank and see if it runs.

Picture059.jpg

Once I knew the harness would fit I installed the new battery.

Picture061.jpg

The rectifier only goes on one way, I'm not sure why though.

Picture062.jpg

The ground was really rusty, I'm not sure there was any continuity here.

Picture066.jpg

The new coil came with a new spark plug wire, but I had to order the cap seperate.

Picture067.jpg

I couldn't get the cap on because the rubber boot wouldn't let me twist it into place. The cap has a screw inside which should screw into the new wire. I pulled the boot back over itself and was able to get the cap on the wire.

Picture068.jpg

New plug, cap and coil. The old plug looked really good so I contemplated not changing it.

Picture065.jpg

the old coil, it wasn't from one of these bikes and the lead wasn't attached very well. No wonder it wasn't running.

Picture069.jpg

The throttle tube is not correct, but neither are the handlebars so maybe they go together. Once I cut the throttle cable the tube rotated freely.

Picture073.jpg

This is the manifold that goes between the carb and cylinder. There is a hard plastic gasket between it and the cylinder, but this one had some hard black substance and a paper gasket instead.

Picture075.jpg

The manifold cleaned up and the new carb.

Picture083.jpg

The old carb. It was still full of gas, bright green in color. anyone know why its that color? It looks like antifreeze.

Picture079.jpg

Once the carb was on, I attached the cable to the throttle tube and it worked great. After I took the old carb apart I went to put it back together and the return spring is much stronger than the one in the Chinese carb. I'd like to get the original working again.

Picture080.jpg

Carb with throttle closed.

Picture081.jpg

The carb with the throttle open

I'll give it a shot next weekend and see if I can get it running. I'm going to rebuild the engine with at least a valve job, rebore and rings so I just want to hear it run before I tear it down.

I have a list of other things that need done to the engine such as gaskets and seals.
 
Well, I reached the end of the road on this project. I was going to change the oil today and couldn't make the drain plug budge. I took a closer look and there was some type of adhesive between the bolt and the crankcase. It was hard, but I couldn't tell what it was. I got a bigger socket wrench and gave it another shot and it came loose, but the adhesive was JB weld or something similar. The crankcase had been broken and fixed by gluing the drain bolt into the case. At this point I think I'm finished unless I can find a case really cheap.
 
Sad to hear it might end that way. Do you think an XR100 engine would slip into that frame?
 
Indeed. I used to joke about Honda making screws out of lead. I removed quite a few with an impact driver, and had to slot a few more with a Dremel tool.

Is there room to use a Heli-Coil or a Timesert in the drain hole?
 
Back
Top