Topic: 1971 CL70 Project..... 117cc *Updates* and now a CL90, too!

[Scott S]

 For some crazy reason I've been itching to do a small cc bike and swap in one of the Honda clone engines from China.

 Well, a couple of days ago I picked up this 1971 CL70. Pretty darn complete except for a few small, cheap miscellaneous parts. The engine turns over and has compression.






 It came with a small box of spares, too. My intention is to swap in, probably, a Piranha 140-160cc engine. They seem to get a little more love than the Lifan engines, even though a lot of people use the Lifan 125.
 The larger engines are a couple hundred dollars more expensive. I'd love to hear from any of you that have experience with the pit bike engines. Is it worth it, power wise, to spend $200-300 more for 25-35cc?

 Also, apparently the CL70 engine/clutch/trans is very desirable. I'll be hanging on to this one. Everything I'm doing is bolt on and reversible.

[Scott S]

One thing that concerned me is that the box 'o' spares included a shift shaft and some sort of selector(?).
 I straightened the bent shift lever and attached it and found all four gears, and the clutch works, but now I can't get it back in neutral.
 

[Scott S]

 Hope you guys don't mind me posting this here...HEY! It IS a SOHC.... 

 The plan all along was to keep the patina. The tank had some varnish and minor rust inside, so I started to clean it using my tried and true methods.
 Here are all the fluids I needed.

[Scott S]

 I was missing the gas cap and the plug I used allowed some of the cleaner(s) to escape. It was then that I noticed that it was working on the external rust, too!
 The marine clean (left over from a POR 15 kit) really did the best. It foamed up like peroxide and baking soda. It's possible I could have left it on there and got even more off, but I was worried that it might start eating away the paint and stripes.

 The inside came out nice. There's still a tiny bit of rust at the very bottom, but with fresh fuel lines, a filter, etc., it should be just fine.

[Scott S]

 The bonus is that the tank is much more silver now!

 I sprayed underneath with rust converter. I'll go back in a day or two and tape it up and paint the underside with some flat black or something.

[Scott S]

 I'm really happy with the way it turned out!

 It gives me just enough patina. I cleared it with some fuel resistant clear coat from the hobby shop. Not as good as the SprayMax 2K or a professional clear, but should be plenty fine for this project. The main thing is that the original paint is protected.

[Scott S]

 I also scrubbed up the seat with some car wash soap and a brush, then treated it with leather/vinyl conditioner.
 Not perfect, but perfect for this project.

[Scott S]

 The dog and I finished up by sitting outside Creepy Van, listening to some tunes, having a beer and some pork rinds.

[Scott S]

 I can get an aftermarket battery cover for this thing, but would any of you guys have a Candy Sapphire Blue cover sitting around?

[SOHC4 Cafe Racer Fan]

I'm really happy with the way it turned out!

 It gives me just enough patina. I cleared it with some fuel resistant clear coat from the hobby shop. Not as good as the SprayMax 2K or a professional clear, but should be plenty fine for this project. The main thing is that the original paint is protected.

That's a cool survivor look.

[Scott S]

 Thanks! I would have been happy with the rust, but this is even better AND protected.

[Scott S]

 I talked to the guy at FirePower mini's today and after a lengthy discussion, I've decided to go with the 117cc using the stock engine.
 One of the biggest factors is that I would have lost the CL exhaust with the clone engine. The exhaust is part of what MAKES the bike, to me.

 He believes that with the low miles, better Honda clutch and transmission, etc., that I'll get a good compromise of power and longevity. Plus, it'll be a Honda, too.


  Oh....and here's why there's a shift shaft in the box of parts:



 The splines are broken off right where the pinch bolt goes.

[Scott S]

 Took it outside and gave it a good scrubbing. Polished the chrome and waxed the paint.

[Scott S]

 Pulled the wheels for new tires. I'll be pulling the forks soon to change the oil and install the new gaitors that came with the bike.

[strynboen]

hey i have a 1972 cd 50..it can be sold for more then my  cb 550...this small hondas are made of gold...keep the honda engine they are worth the work to be done..have made a lot of china engines..casting/kaburettors/,,,all are bad kvality...but runs fine...but the honda engine are ART...finest small engine in the world

[Scott S]

 Yeah, I've decided to build the 70 up to 117cc.  Supposedly, the clutch and transmission in the 70 are much better than the China engines. I can also keep the stock Scrambler exhaust and the engine will still be a HONDA engine. Plus, I won't have to convert to 12V either.

[strynboen]

think the exhosts flange are the same as honda type..but more simpel made on the china..have not the loose half parts..
only thing to miss ..are the bearing in cam/head...and elektronic egnision..i miss that on my old 1972..but like it are komplet stock 50 cc..

do you have to get a longer stroke to get 117cc..i have tryed to put china crank in a honda...but it fits not in the ignision side..crankshaft /svinghweeel oilpump dont fit

[Scott S]

 I got bored so I dropped the engine. I can honestly say I've never pulled an engine single handedly before!
 It looks like someone has been in there before. The wiring harness is spliced. I'll solder it back together and shrink wrap the wires before installing the rebuilt engine.

[Scott S]

do you have to get a longer stroke to get 117cc..i have tryed to put china crank in a honda...but it fits not in the ignision side..crankshaft /svinghweeel oilpump dont fit

 Yes, it's bored and stroked. I'm letting FirePower Minis build it for me (the labor is inexpensive and he can turn it around in about a week). You have to bore out the cases.

 The kit is similar to this and comes with big valve head and bigger carb.

http://www.ebay.com/itm/171254257956?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

[strynboen]

yes it are japanese kvality parts...good for a old honda...

[Scott S]

 I'm going to let Terry at FPM assemble it for me. His labor charges are VERY reasonable and, since he's taken the time to talk to me about my options and walk me through the process, I don't mind sending him some business. If I were to do it myself I'd have to pay to have the case machined and, in the end, the final cost difference is minimal.

 He said he'll change out a couple of parts specific to the 70 engine for my build, but this is essentially the kit.



 And I decided to give this oil cooler a try. Terry says Honda did  a nice job on the Scrambler exhaust and it should work fine with the 117cc kit. An oil cooler is never a bad idea, and I'm in South Carolina, where it gets very hot and humid in the Summer.

[Scott S]

Changed the fork oil (95cc of 20W) and installed new gaitors.

[hoodellyhoo]

Great job on the little 70 so far! I really like they way you're doing it and plan to do the same on my S65 whenever I get around to working on it. For the most part the bike is completely roached (don't be fooled by that tank, it's a replacement). It is 100% complete (i have everything not in the pic) and the motor isn't stuck. Not matter how crusty it is I couldn't bear to part out a complete bike. It would cost a fortune to restore it so I'll just clean it up as best I can and ride it as-is. I can't wait to see what kind of milage I can get from it too.

[Scott S]

The CL70 came with a 49T rear sprocket. Those are hard to find except in Genuine Honda ($$).

 The rubber dampers in my bike seem to have a little play,too. I'd like to replace chain, sprockets, dampers, etc., all at once

 It's been suggested that I go with a 2.7:1 ratio in order to cruise at 50-55 and be able to see slightly higher speeds. I will be running the 117cc kit.

 The 18T/49T combo seems to give me a very large front sprocket. Here are some other possible combos that are readily available. Which one would you recommend?

14/38 = 2.71
15/40 = 2.67
15/41 = 2.73
16/44 = 2.75
17/46 = 2.71

[Scott S]

 So, I got the new sprocket, dampers and chain adjusters. The new snubbers are a TIGHT fit and, after much beating, banging, WD40, heat and cussing, got them installed.



 It was then that I noticed the castle nut seemed to thread on very deeply; the cotter pin wouldn't really do anything to hold it.




 I referred to the parts diagram to make sure I wasn't doing something wrong and only then did I notice that I'm missing the damper cover, part #7 in the diagram.



 It wasn't on my bike when I took the old sprocket off. The dampers are IN THERE....I mean a TIGHT fit. I could remove them, but I sure don't think they'll be coming out on their own, especially if the old ones didn't. The old ones literally fell out of the hub when I removed the old sprocket.
 Think I'll be OK?