CT70 out of storage!

JUst got my Vermont Registration! I'm legal now. So now Need to get insurance on it, I guess.

Gonna take the written DL test soon too,

Adam-NLV said:

JUst got my Vermont Registration! I'm legal now. So now Need to get insurance on it, I guess.

Gonna take the written DL test soon too, View attachment 63308

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How long did the process take? Any hitches along the way?

This was just a renewal, i was originally gonna register it here and you need it inspected here so decided, pay Vermont another year by then i will have my M liscence.

But the original process isn't too bad, about 2-3 weeks. A good way to check is when they cash in your personal check. They cashed mine Sept 4th and i got my registration yesterday.

So the bike feels like its bogging down and speed takes longer to get to. I pulled the plug and it looks like the engine is running rich to me... that could be why its kinda sluggish. It seems like there is fuel on the plug, could it be, its not burning oil, the exhaust looks good.I guess i should turn the fuel air mixture to less lean... I'm thinking.

Looks like it's on the rich side but not pig-rich. Forget about turning any adjustment screws for anything above idle. I'd try raising the jet needle C-clip 2 grooves and going back out for a test run. Only problem is, I don't recall if the 12v era carbs have adjustable jet needle height. Doesn't look like you're burning oil. The symptoms you described are more consistent with a lean mixture. How's the air filter? Maybe try a fresh tank of fuel, from another source. A clogged air filter, or "goat piss" fuel could cause the power loss/bogging and dark plug tip.

Get rid of that plug that came with the bike back in the 90's, what happened to the washer???

Take the ''looong ride'' to the gas station and buy fresh fuel. At least you can do 145mph on that highway. HA HA!

I went back down to that dirt Trail i wiped out on last time. The bike bogged out some in 1st, and I think the 33T rear sprocket is better for roads, for dirt trail riding, I'd stick wit the 35 Tooth. The bogging issue has to be taken care of....

The Air filter, it could be dirty, that's one thing I don't remember cleaning.I definitely think its running Rich.. Will get a new plug with a washer too. Bogging out in 1st Gear is not the time to Lose power!

I have a stock 79' carb that looks really clean; would that be a heasier Carb to Run on a 91 engine? Seems the carb on it now is fixed and not much adjustments.
This town is almost 2700 ft elevation, that could have some effect on tuning it.

How crumbly is the air filter? You are looking at a plug that has been in the bike since it was new. There is a order for things, you know.
Here is what I would do... Fresh 93 octane gas, make sure the filter is 100% GOOD + CLEAN + REOILED and put a new plug in. Then ride it around to test.
You didn't mention doing anything that was recommended yet... Now you want to change the carb?

Ok will clean the filter and get a new plug on it today....

I also must consider that a 72cc engine is capable but still quite small, 35 - 38 mph is about at its limit.

You've just been taken to the woodshed by OLD CT.

racerx said:

Looks like it's on the rich side but not pig-rich. Forget about turning any adjustment screws for anything above idle.

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Whoo! Not today-hombre~! I just adjusted the carb and the performance is back!! I'm a carb genius

I turned the gray crank lever to the left and the rpm's went up over idle speed. So Then i turned the idle screw to adjust the idle to normal and went for a cruise. Previous I changed the spark plug to a newer one... The bogging out is Over and its back to quick speed again around~38mph.

There is a crack near that lever, I wonder if that is why it went out of adjust? Anyway itt has great throttle response, no hint of bogging in 1st gear. Its cruising great now and the plug looks Swell

Here's the plug yesterday:

Now after the adjustment:

There is a crack on the carb casing.

Your running/performance issue is gone; the machine running normally once again...cool biz. That's what matters.

I stand by what I said, that idle adjustments begin losing their impact once 1/8 throttle is reached, quickly tapering off to nothing long before WOT is approached. That's basic applied physics. Whatever it was that caused high-rpm bogging, under load...and the blackened plug, at high cruising speed, had nothing to do with idle mixture. Next time you have the carb off the bike, look through the venturi with the slide adjusted to proper idle speed. That tiny little opening is barely large enough to see light through...probably 1% of the venturi cross section. The pilot circuit has to deliver a matching amount of fuel and with tight precision, or you won't get a stable, solid, idle. The main fuel circuit is completely deactivated at idle. It would be a case of "never the twain shall meet"...except for the fact that the pilot circuit virtually doesn't matter above 1/4 to half throttle. Believe it, don't believe it...your call.

As for that "gray lever" it's a limiter cap for the pilot airbleed adjusting screw...an emission-compliance piece, similar to 1970s-80s automotive carburetors. Remember the hardened welch plugs that prevented adjusting the idle mixture on Quadrajets? Pretty silly stuff, back in the day.

Fyi these redesigned later series Kehin carbs, the few I've rebuilt & dialed-in, seem to work well within those limited, stock, parameters unless they are either in need of rebuilding...or too far gone to be rebuilt. In your dry climate, oxidation shouldn't be an issue and the carb ought to last another quarter century, as long as you don't let it sit, unused, with gasoline inside, for long periods of time.

Thanks Bob, I was worried that maybe it may have gotten a ring problem sealing issue. . i've been taking it relatively easy on it but do run it up for just a little, here and there. I Always keep tabs on oil & Temp.

After I bought the bike I rebuilt the carb with a kit but had to put it in storage w/out ever starting cause of house-move.... But It occured to me i never spent much time adjusting the carb after it started and could be it just needed some fine tuning.

Like you said The machine is back to normal, will keep an eye and see if that lever cap is vibrating & turning itself. Can't ride no Mo today...The wind picked uP Big Time and this little bike don't like the wind.

It would be nice to have a lil more displacement and another gear for just an occasion!
I still have a new 4-speed e-Start Lifan 110cc. It runs strong and has just over a hundred actual miles.Its also 12 volts like the 91'. I may look into that swap later on down the road.... Seems like a better choice to increase the bikes speed w/out modifying the stock Honda engine.

Check it out.

Two speedometers a CM 400 & CT70. Both speedometers powered by the same drill, It seems the cm400 would have a different reading than the 72cc CT70. The wheels on the cm400 are 18". They both read 9 mph Go figure?

Construction front: New house getting built behind my casa. Weird how they angled it but it save the MT view.



Here's a 737 Jet Airliner!


Leo doesn't like the new neighbors.

The CT70 speedo reads 7 mph. The other speedo reads 8.

Forgot to mention the drill is floored on both speeedO's, with fully charged batteries.

I loaded the wrong pic! Thanks for the heads uP OC! they both read 9 mph!

I think it’s the speedo gear drive ratio that is different. I’m not that surprised

Speedo input spec is the same for both of these speedometers. It may be across-the-board, with Honda bikes of the era (back to 1969, at least). There was a slightly different revs/mile spec on the mid-1960s units I've seen but, I can't recall the numbers and have no idea what year(s)/model(s) saw the changeover. Suffice it to say that you should be able to use this 80mph gauge, as long as you can find a cable of the appropriate length with the right square end & threaded barrel to screw onto it. Above 45mph, you should also see better accuracy...which gets better as speed increases. The round speedometers used in the K1 era can be extremely "stingy" at the high end of their range.

Here's the Tachometer of the set .

I wasn't gonna use them but i found the results disconcertingly interesting and leads me to surmisethat Honda's speedo manufacturer may use the same drives for several Honda models.

I was just checking if they worked, gonna put em' on feebey. Just cleaning out some storage junk, gotta pay off the credit card!