Comments: 1-15, 16-22
The gas tank is rusted out.
Kills headlight bulbs (always use a fully charged battery, or kiss the bulb goodbye).
Nothing really has gone wrong with bike.
Oh, replaced the carb... rust kills!
This is an amazingly reliable bike. Small yes, and it sure is not a hotrod.
It is a great bike to learn how to ride, shift gears, and balance on a bike. ***Stay away from pine straw... yikes!
Here it is 2005, and the bike was made in 83. Still cranks! I had to replace the carb (replaced with a carb off a 70's model Passport, and it runs fine. The gas tank rusts easily, and rust is bad for the carb... I wish I could find a plastic gas tank replica).
I have managed to tune my 1982 C70. I fitted a larger rear sprocket and chain assembly. I removed the air filter box and swapped for a cone filter. My last modification involved swapping the carburettor for one off of a 1986 CB-125N.
I have had it up to 79MPH, but it was very wobbly at that speed. I almost fell off when I hit a small bump in the road. I am now welding extra metal to the frame so it can handle better.
79mph eh? What, did you manage to somehow fit a 250cc motor into the frame?
First off, the speedo only goes to 55mph on 80-81s and only 50mph on 82-83s. Second, a carburetor from a 125 is way too big for a 72cc motor. You might be able to start it, but tuning would prove to be quite a chore. Third, at 79mph, the rpms would probably cause the stock clutch to explode and the tires to shred.
I think you meant 79 kilometers per hour.
Never seen people blow so much smoke when it comes to these litle bikes.
Oh, for the record, I have a 110cc Honda Nice motor installed in my 82' Passport. It will bury the needle on my 50mph speedometer. On a good day (warm weather, flat road, tailwind) it will probably hit 65mph. That's with an open exhaust and a 22mm carburetor.
Now, that's not smoke.
Actually my Honda C-70 does not have a clutch. The 125 Carburettor bolted up good with a new throttle body assembly installed and spacers.
The C70 does have a clutch. The clutch is designed so it works using centrifugal force. As the engine spins and reaches a certain RPM, the clutch will engage, thus driving the transmission. The design of the clutch removes any interaction between the rider and the system. The setup is similar to a conventional manual motorcycle clutch, but uses more parts and appears rather complex in design and in operation. I would have thought, if one of these clutches decided to explode as one of the comments correctly suggests, the amount of damage would be catastrophic. Be careful.
Yes, it is referred to as a semi-automatic, centrifugal clutch. It does require shifting, but no clutch lever action.
Honda did however make this same motor with a manual clutch. They could be found in the models CT70H, XL70, SL70, CL70, SS50, CD50 and a few others.
Now if you're really creative you CAN make your C70 a manual clutch by swapping the parts from one of the above mentioned bikes. You can keep it looking almost completely stock too. You just need to do a little cutting on the legshield. Oh and you'll need to source a left handlebar switch/parking brake lever from a European C50LAC (which has a FULLY automatic motor)!
See here:
http://www.cmsnl.com/c50lae-england_model8268/partslist/
My 1980 C70 is no longer a C70. I have dropped in a lump and gearbox from a 1989 C90. I then transferred the carburettor from a 1986 CB125, have fitted bigger sprocket/wide chain. I had to upgrade the front brake to solid disc set up for safety due to the slightly extra power. Coupled with a total cost of 600 pounds including buying the bike, it is a bargain. It still returns 80Mpg. I think the Cone Air Filter helps.
Right now I am having problems with an initial flat spot, and a missing idle when cold. I have had 92mph out of it on a long hill, not reccomended for more than 5 seconds because it wobbles a lot on the thin wheels at this speed. I am thinking of removing the rear shock and hard tailing it to remedy this. Anyone ever hardtailed one of these?
Interesting comment, I own a 1988 C90, I have not Hard Tailed it, but I did inherit a KMX 125 that my brother had crashed. My father managed to weld on the muffler for me. It sounded very loud, but would stall unless throttle kept two thirds open, even when warm. It was a real babe magnet in my senior school year, by the way it sounded though, I told everyone I had dropped a 250cc motor in the frame.
A C90 Scooter with a KMX Kwaka Tailpipe, that must have sounded nuts! No wonder it bogged down so much, funny.
I am not sure with all the 70+ miles per hour speeds spoken so highly of on here. I think I would crap myself...
But I have got about to 55ish.
I paid two hundred for the bike with title, and
spent 119 for a new roller bearing cam and 88cc upgrade for the engine.
Put a new 15 tooth front sprocket on the bike.
And changed to a #90 main jet cause of the increase in engine size - it was running a little lean.
It's my around town cruiser, and I can keep up almost everywhere, including the 45mph zones. It works well.
Yes friend, going above 70 MPH on a C90 is very very scary, because of the thin wheels and wobbly suspension.
Hi there, just bought another 1992 Honda C90 semi auto, great bike and nippy too. I'm having problems with the gears though, when I'm near top end in 3rd gear, it seems to slip into 1st or N. Has anybody got any advice, and what oil are people putting in theres? 10w-40? Thanks.
I have a 1982 70 passport, and would like to find a owners manual for it.
You can find useful info here: http://autos.groups.yahoo.com/group/Honda-C70/files/
including the user manual and the shop manual.
Well where to start? I have an old 1975 C70, and its died soo many times. I am now getting in touch with a guy in the trade, and he has a nice little 125 tumpster engine to go in her (it's a honda based pit bike engine) with all the carb and the lot for the manual upgrades.
I was reading your threads, and it looks like I may need some new brakes. What is the best to use, and will I need to get a wider back tire, coz it looks like it could wobble a bit at say 100. I have a lot of mechanical knowledge, but coming to customizing I ain't got much of a chance!!
Any help well needed.
There is a new 13.9 hp 140cc race tuned engine that just bolts onto the trail models for 425 bucks.