Woodyhfd
Woodyhfd GRM+ Memberand HalfDork
7/10/08 9:48 p.m.

Last week I posted a photo of my vintage pit bike project. I've done some more work and taken a few more pictures, so I figured that it was time for an update.

It's a 1971 Honda CT70 Mini Trail. I bought it last year, sight unseen from several states away, with the intention of using it as a parts bike. They're easy to work on, parts are plentiful and they're actually pretty collectible. When my friend delivered it to me, it was looking pretty neglected, but it was surprisingly complete.

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I decided that it was much too good to use as a parts bike. I cleaned it up little bit and removed most of the chrome, as I wanted to try electrolytic rust removal.

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The electrolysis worked pretty well. The rust gets converted to a black oxide powder that brushes right off. Any pitting remains, but the rust is gone.

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So I thought that I would throw the chrome back on, put in a new battery and use it as-is. Then last week, I decided to put on some new fuel lines, since they looked to be 37 year old originals.

And then the fun began.

I had put the little bike in my basement for the winter, so that's where the work started. I had to remove the seat and the plastic fuel tank to get at the fuel lines. I also removed the air cleaner assembly for better access to the carb. I noticed that the rubber intake elbow was cracked, so I went to the web to order a new one. Almost every part is available for these things from Honda and most of them are surprisingly affordable. Since I was already placing an order, I figured that I might as well replace the original tires and a couple other small things at the same time.

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The wheels are two piece centerless rims, which makes replacing tires relatively easy. There was a bit of surface rust on the wheels, so I decided to sandblast them, along with the foot pegs and the kickstand. The hubs serve double duty as the brake drums, so I took them apart and cleaned them up. The pads and wheel bearings looked good, but when I sprayed the hubs down with brake cleaner, the paint came right off, so I sanded them down, primed them and painted everything.

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Before reassembling, I decided to polish up the clutch housing and the points cover (look it up, kiddies). I didn't like the way it was coming out, so I pulled out the engine for a little more thorough cleaning, minor detailing and some paint work.

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After the paint dried, I recruited my seven year old nephew to help me bolt the engine back in. He also helped out with the wheel and brake assemblies. I may have been able to do it without him, but it sure was a lot easier having him there.

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So, as it turns out, replacing two feet of rubber fuel line has now taken three vacation days. But they have been three of the most enjoyable vacation days that I have used in a long time. The bike is still hanging in the basement. In the morning, I'll put the carb back in, add the new battery, some fuel, check all the bolts and hopefully take a few laps around the neighborhood.

More photos to follow, once it's back out in the sunshine.

rob_lewis
rob_lewis Dork
7/10/08 11:30 p.m.

And now, another Ebay search has been added to my favorites.....

Sweet bike!!

-Rob

oldschoolimport
oldschoolimport New Reader
7/11/08 1:36 a.m.
Woodyhfd wrote: So, as it turns out, replacing two feet of rubber fuel line has now taken three vacation days. But they have been three of the most enjoyable vacation days that I have used in a long time.

thats exactly how I felt once my 50 was done. they are a pleasure to work on, since they are so simple. the ct looks great! it makes me want one that much more. congrats!

aeronca65t
aeronca65t New Reader
7/11/08 5:51 a.m.

Nice! I gave one of those away some years back. I regret it.

Here's our actual pit bike (with gooney "side car") that we use at races. It's on the trailer with the race car right now (heading to Pittsburgh Vintage this morning).

And here's my favourite pit bike (this one usually shows up at the PVGP).

wreckerboy
wreckerboy SuperDork
7/11/08 7:11 a.m.

Aeronca was nice enough to allow me use of his pit bike at BeaveRun one year. It is the single silliest way to get around the track and I really didn't want to give it back to him at the end of the year. It's also the reason I purchased a old (1982) Honda moped over the winter that had only 102 miles on it.

Woodyhfd
Woodyhfd GRM+ Memberand HalfDork
7/12/08 10:22 p.m.

Here's another update:

This morning I reinstalled the carb, added a tiny K+N filter and finally attached those new fuel lines that started this whole project in the first place. I had a few other odds and ends to reattach, like the tail light, points cover and the new battery.

These things were street legal when they were new and this little bike was actually registered in Hawaii at one point. When I was polishing up the shocks, I left one of the old Hawaiian inspection stickers in place and I reattached the old license plate that was on it when I got it.

I made one final pass with the wrenches and carried it back up the stairs and out of the basement (143 lbs., ugh!).

I thought it looked pretty good back out in the sunshine, especially considering what it looked like when I started (refer to the photo at the top of the page). I filled the oil (1.5 pints), added a little gas, gave the starter five kicks and it fired right up, which I expected, since it says "Honda" on the side. After it warmed up, I made a few passes up and down the driveway and then pulled it back into the garage to check for leaks and loose bolts. Everything checked out, so I proceeded to crank off about 150 hot laps around my house. I didn't have enough room in the yard to get into third, so I made a three mile pass up and down my street. It tracked nice and straight and the front wheel centered itself really well, which was a nice bonus, as I was afraid that it would be twitchy with the short wheel base. Top speed when new was listed as 47 mph. I got up to a little over 35, which was plenty for a bike this small on knobbies. Plus, I didn't want to attract any more than attention than necessary, which turned out to be a losing battle. This ride wasn't very discreet.

The most amazing part to me is the fact that after my 45 minute ride, this little 37 year old Honda didn't leak a drop of oil or gas! Photobucket Photobucket Photobucket

....and, of course, here's the obligatory GRM Money Shot! Photobucket

stuart in mn
stuart in mn Dork
7/13/08 8:47 a.m.

That's the great thing about working on minibikes - even a full on restoration doesn't have to take a lot of time or money. You should see about getting it licensed for the street again, it would be fun for running down to the corner coffee shop or to the store. When I was a kid one of the guys in my school had a CT70 on the street, and he must have put thousands of miles on that thing - he rode it everywhere. He was about 6 foot 5, so he kind of looked like a circus bear riding around on that thing.

Edit: I just looked at the first picture again...what was that angle iron thing bolted to the swingarm? Trailer hitch? Wheelie bar?

DILYSI Dave
DILYSI Dave SuperDork
7/13/08 9:36 a.m.

Well done! What a cool bike! My first project with an engine (I had a few years of being the local BMX bike mechanic to all my friends) was a Honda Z50 that a buddy pulled out of of the woods.

It looked ike this:

but had a dented gas tank the whole time I owned it because I couldn't afford to replace it, and apparently the person who abandoned it decided to kick the E36 M3 out of it before they did. Te extent of the project was getting it running (got to learn about points, magnetos, etc.) and a brake rebuild that turned into a wheel restoration like you did.

Woodyhfd
Woodyhfd GRM+ Memberand HalfDork
7/13/08 12:29 p.m.
stuart in mn wrote: You should see about getting it licensed for the street again, it would be fun for running down to the corner coffee shop or to the store. When I was a kid one of the guys in my school had a CT70 on the street, and he must have put thousands of miles on that thing - he rode it everywhere. He was about 6 foot 5, so he kind of looked like a circus bear riding around on that thing. Edit: I just looked at the first picture again...what was that angle iron thing bolted to the swingarm? Trailer hitch? Wheelie bar?

Yup, that was a tiny trailer hitch. I suspect that the original owner in Hawaii must have used it to pull a small grocery basket or something.

I don't think I'll be registering it, though, as I just ordered a Ruckus. I may put this one up for sale.

mrhappy
mrhappy New Reader
7/14/08 8:17 p.m.

ct70 engine swap

mattmacklind
mattmacklind SuperDork
7/14/08 9:28 p.m.

When I was like 8, I got a go kart for Christmas and my older brother got one of those! Same color and everything. I see yours has a license plate holder. My brother's had one as well and turn indicators. Is your model street legal? Looks great, I'd like to pick one up but these days people ask quite a lot for them, more than they were new in some cases.

Tyler H
Tyler H GRM+ Memberand Dork
7/14/08 9:40 p.m.

My buddy had one of these when we were kids. It looked exactly like that, same color and all. With both of us (85lbs a piece at that point,) that sucker would still do 40-45mph.

Wonder project. Thanks.

Tim Suddard
Tim Suddard Publisher
7/14/08 10:25 p.m.

That was the first bike I ever had when I was ten years old.

We talked about a pit bike/pit vehicle story, but haven't gotten to it yet.

Woodyhfd
Woodyhfd GRM+ Memberand HalfDork
7/15/08 6:20 a.m.
mattmacklind wrote: When I was like 8, I got a go kart for Christmas and my older brother got one of those! Same color and everything. I see yours has a license plate holder. My brother's had one as well and turn indicators. Is your model street legal? Looks great, I'd like to pick one up but these days people ask quite a lot for them, more than they were new in some cases.

Yes, they are street legal and this one was registered in Hawaii. Mine is an early model ("K0" in Honda-speak). The later ones came with turn signals, but I guess they weren't required in '71. They look better without them.

According to a Cycle Magazine road test from 1970, they cost $305 new (they go for several times more than that these days) and were good for 47 mph.

Jensenman
Jensenman SuperDork
7/15/08 6:35 a.m.

My SL70 was $345.00 brand new in 1971. My dad talked the local Honda dealer down $20 because the tank had a couple of scratches. I mowed grass and threw papers my azz off to pay my pop back.

Now I guess I am gonna have to find another pit bike project, since the Hodaka is sold.

jimbob_racing
jimbob_racing HalfDork
7/15/08 12:56 p.m.

You did all that work and now you're going to sell it? What's something like that worth? If the price is right I'd like to be first in line please.

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