Thread: information on 70 Mods wanted.

Anyone got any good pictures and information on 70 Mods. Please post them. CDI upgrades. Brake upgrades, Engine. Thanks

What year is your CT70? Makes a big difference on the modifications.

Here's my 1993:

Give me the year and I'll set you up with a ton of resources, some of which more then you'll want to spend on a CT70.

Now thats a nice bike!
Give us some specs Pony!

More than meets the eye...

I have a 1970 and 1971 both are blue. One runs and the other I haven't got in going yet.

I like the Pipe on the Pony Express looks alot like the CRF 50 Pipe.

Racerx what disk brake are you running? is it a kit?

Racer X - Damn, that is one ugly bike! When are you going to get around to installing the new wheels, exhaust and all the other goodies you have lying around to make that thing look good? Or is that your beater bike while your good 'un gets finished? I can't keep track of your projects these days.

Listen to Racer X people, he knows his stuff, as shown by his beater bike above...


MadMax - The pipe is made by R Design out of Japan and it's made for the Honda Dax (JDM version of the CT70) If my memory serves me correctly, it was around $200 before shipping from Japan. It's of average quality and is loud, but when you price JDM performance pipes, $200 is on the cheap side.

Performance parts will depend on your pocketbook and how crazy you want to build your bike. If you want to stick with your 6V system, you can go here for cost effective performance upgrades, and 88cc Big Bore Kit with 20mm carb being the cheapest route:

www.hondatrailbikes.com

Aftermarket swingarms run $350-$550 out of Japan depending on length and materials.
G-Craft
Regaspeed

Rims made by G-craft run around $275-$300 a set before shipping and are available in 2.75-4.00 widths. On a stock rear hub, you can fit a 3.5 inch wheel, and a 120/70/10 tire. You can run 4.00 inch rims if you fabricate some spacers. I'm sticking with 3.5" rims and am waiting on tires.

That's just the beginners list. I'd get everything settled, decide if you want to convert to 12V operation and decide on a powerplant then move forward with your build. Racer X has a Honda Nice 110 base engine that is the best tuning engine available in the world, but can no longer be purchased new. Touch base with him and he'll fill your head with more ideas you can shake a stick at.

I'll get to my specs at a later time. The base bike started life as a 1993 CT70, 12V CDI motor, and is going to be upgraded from it's 88cc 7.5HP state to 117 here over the winter when I have some free time, and I'm dropping a 4 speed JDM gearbox in it as well. The 3 speeds weren't made for the street. I'll also be adding an oil cooler and some other supporting engine parts. The triple tree and rear lighting are off of a 1995 Honda AB26 12V Dax, turn signals are Kitaco, Skid plate was made by DPMmx.com for the CRF50, and the Bore Kit, Race Head and carb are Honda Trail Bikes pieces. Turn signals are Kitaco. Rest is all Honda, paint is original, I repainted the wheels and added the retro decals.

Nothing new to report...

Dan

That's an entirely new Honda front end. It's been adapted from Honda Nice parts. All of the parts are OEM Honda: twin piston caliper, master cylinder and the largest disc that will fit a CT70.

Between wheel selection, disc size and the precison required to get it right, disc brake conversion can be a can of worms. Virtually all aftermarket wheels require hubs from the same manufacturer and those hubs tend to cost as much or more than the wheels themselves. Aside from being pricey they can complicate the choice of disc.

I did an end-run and used this bike to prototype a CT70 disc front end that uses the stock CT70 hub & speedo drive and keeps the price reasonable. I can now produce this front end as a kit.

Thanks for the information. I know my bikes are older but I would like to update them to 12V CDI if possible. I've been told to just leave them 6V because I would have to change bulbs and other things. thats not an issue. Both bikes are going to be stripped down and redone. I've been looking at the 88 kits for them . I found a nice kit including the 20mm carb and complete head for $390.00 I been looking at the the 4 speed trasmission. I've also found a nice stroker case to build up to a 120 for $105.00 So I'm still on the fence on the direction I want to go with the little bombers.

I have a friend that is building a Z50 and using a CRF 50 motor that he is putting the 88mm kit on. He says that the CRF motors are build better. ?

He is using bullet caps on the wheels with a piece of all thread so it will have bullet caps on both sides of the wheel.

I'm going to use a 2005 CRF50 on a 1976 Z50 project, and the CRF50 motors are 12V CDI motor, but don't have lighting coils. You'll have to either rewind the stator, or use the lighting coils off of a 1988 ZB50 or 1991-1994 CT70, or an aftermarket 12V stator assembly with lighting coils. Then you'll have to custom wire provisions for the CDI, the CDI harness, and the voltage regulator. Then you'll have to fit a 12V battery, change out all your bulbs, and you'll be good to go.

Or you could just purchase the dratv.com monster motor, and he has all the wiring instructions on his website and has all the adapter harnesses. Stock, the motor will put down around 7HP, just a touch less then a good 12V 88cc motor with a good race head.

Or you could get a Honda Nice 110 (Talk to Racer X) and slap that bad boy in with around 9.5 HP stock, and have an even better motor.

Either way:

Doable with good wiring diagrams.

There are more advantages to the older bikes than disadvantages, epsecially where registration and insurance are concerned. Generally speaking, the older the bike the less regulations apply to it.

Bulbs shouldn't a be problem; if nothing else, the late model CT70s were 12v, so you've got a good starting point. Wiring isn't all that complicated either. There's so little involved with modifying an existing harness that it's almost a joke. All you need is a 12v diagram and you could easily make your own if need be, using the OEM connectors from your vintage original. Frankly, the newer wire harnesses aren't all that different for your purposes. Most of the differences I've seen are simply additional leads for turn signals and accessories that you won't be using anyway.

Coming up with the most effective motor combination is where things get complicated. An 85cc kit is relatively inexpensive but then the results are relatively mild, a bit more grunt and another 5-7mph or thereabouts. Should you decide to really wake up those extra cubes, then cam, head & exhaust mods come into play. Go too wild with the cam, and your engine will make lots of high rpm hp, but will be disappointing down low, in other words a race engine. A stroker crank can be a bit tricky. You'll need either a longer cylinder or a spacer and usually some machinework for crank clearance, or the aforementioned late model cases. With 120cc, clutch mods become necessary. By the time you add in the cost of a 4-speed tranny, you'll exceed the price of a new 120 motor. While the key components look cheap individually, they add-up faster than you think.

It's all about tradeoffs. The smaller displacement won't have the torque of a 110/120 and you'll have to rev the hell out of it to make that power and that means lots of shifting. Building a stroker motor isn't cheap once everything is added-up. The Chinese 120 that dratv sells is too new to have any field service history. Word has it that the tranny takes 500 miles or so to loosen up and that neutral is tough to find, especially when hot. It, along with the 110, will give you lots of lazy power, making the bike very easy to ride with just a twist of the throttle. The secondary clutch 110 has a decent reliability record, but I can speak from experience that it's not the smoothest engine or tranny I've seen. Parts support for Chinese engines runs hot & cold, mostly on the cold side. The 110 Nice is only available used/rebuilt (though I'm checking out a rumour that more will soon be available) except for the semi auto version. It's big-bike smooth and proven has proven to be nearly bulletproof, along with Honda parts support. But they don't come cheap. By the time you sift through all of your options, you'll probably find that the cost difference between them comes to less than 10% of the cost of your project.

A CT can be setup for just about anything except stunt jumping or interstate freeway cruising. It really comes down to what you want the bike to be and how you intend to use it. Give us some idea what you had in mind.