CT70 Beats Monkey in Drag Race

Did an 80 mile ride today with me on my YX140 powered CT70 and my son on his 2020 Honda Monkey, stock except for aftermarket exhaust. We raced zero to 50 at least 6 times and beat him each time. Couldn't launch as quick since the front wheel gets light, but even with that deficit, pulled him at least a bike length in each gear. Same story with 2nd and 3rd gear roll ons. And the bike was still pulling harder in 3rd at 50. My only disadvantage was range envy. Best I could muster was about 80 mpg, so I would go on reserve at about 40+ miles. Had to bring along extra fuel. He barely used half a tank, so he was getting over 100 mpg. In all fairness, the Monkey is about 50 lbs heavier than the CT, and my boy is about 40 lbs heavier than I am, but that's my story and I'm sticking to it.
 
Did an 80 mile ride today with me on my YX140 powered CT70 and my son on his 2020 Honda Monkey, stock except for aftermarket exhaust. We raced zero to 50 at least 6 times and beat him each time. Couldn't launch as quick since the front wheel gets light, but even with that deficit, pulled him at least a bike length in each gear. Same story with 2nd and 3rd gear roll ons. And the bike was still pulling harder in 3rd at 50. My only disadvantage was range envy. Best I could muster was about 80 mpg, so I would go on reserve at about 40+ miles. Had to bring along extra fuel. He barely used half a tank, so he was getting over 100 mpg. In all fairness, the Monkey is about 50 lbs heavier than the CT, and my boy is about 40 lbs heavier than I am, but that's my story and I'm sticking to it.

That day we went riding my son tried out his new 360 degree camera and made a short video on youtube. The camera was mounted on the front of his Monkey, and although the camera makes itself invisible, you can still see its shadow. The link is
 

Deoodles

Well-Known Member
Did an 80 mile ride today with me on my YX140 powered CT70 and my son on his 2020 Honda Monkey, stock except for aftermarket exhaust. We raced zero to 50 at least 6 times and beat him each time. Couldn't launch as quick since the front wheel gets light, but even with that deficit, pulled him at least a bike length in each gear. Same story with 2nd and 3rd gear roll ons. And the bike was still pulling harder in 3rd at 50. My only disadvantage was range envy. Best I could muster was about 80 mpg, so I would go on reserve at about 40+ miles. Had to bring along extra fuel. He barely used half a tank, so he was getting over 100 mpg. In all fairness, the Monkey is about 50 lbs heavier than the CT, and my boy is about 40 lbs heavier than I am, but that's my story and I'm sticking to it.

Thats not bad but all he has to do is replace the 15t front sprocket to a 14t and you will again see the Monkeys tail light. I run 14/35 and it isn’t even close to the same bike Bonus... it will still get over 100 mpg
 
Thats not bad but all he has to do is replace the 15t front sprocket to a 14t and you will again see the Monkeys tail light. I run 14/35 and it isn’t even close to the same bike Bonus... it will still get over 100 mpg
If I replaced my 18 tooth front with a 16, my top speed would be faster as well, but I pull away from that monkey in any gear. The only way it could keep up is with a 140 lb rider.
 

Deoodles

Well-Known Member
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OLD CT

Well-Known Member
140cc vs 140cc only seems fair.:D Kinda like bragging about a stroker 108cc beating a 88cc kitted CT70. Nothing to it. I will wait for the new video to even watch.
 
140cc vs 140cc only seems fair.:D Kinda like bragging about a stroker 108cc beating a 88cc kitted CT70. Nothing to it. I will wait for the new video to even watch.

1. The Honda Monkey is an excellent bike right out of the box. It rides so much more solidly and more comfortably than my CT70 at 50mph, there's no comparison. Plus you got disc brakes, modern fuel injection, Honda reliability and a warranty. Why mess with a good thing. If it was more power and speed I was after, I'd buy a TW200. Plus the price of the bore kit is probably close to the price I paid for my whole complete YX140 engine.

2. People talk about dropping the countershaft sprocket a tooth to increase top speed. Why is that so important? It'll only make you wish you had another gear when cruising with the engine buzzing away. I think Honda new this when they chose the factory gearing.

3. Honda just announced that the new Grom and Monkey will have 5 speed gearboxes. Now you'll be able to gear the bike for top speed at redline in 4th and use 5th as a cruising overdrive. With the 4 speed, you always end up with 3rd being a little too short and 4th being a little too tall.

4. Obviously, there's no replacement for displacement (turbos notwithstanding), but at what cost. As far as bang for the buck. this motor transforms an anemic CT70, that can barely squeak out 40 mph, to a little hotrod, that can leave it for dead, not to mention the modern 12 volt electrics. The fact that is can out accelerate a new Monkey is just icing on the cake.
 

OLD CT

Well-Known Member
I would be impressed if the race was with equal cc bikes. Cheapo cc's vs expensive cc's. It doesn't matter to me.
Are you afraid cheapo cc's would lose? I have a 124cc that I hand built that will eat the Pirhana 140 for lunch.
 
I would be impressed if the race was with equal cc bikes. Cheapo cc's vs expensive cc's. It doesn't matter to me.
Are you afraid cheapo cc's would lose? I have a 124cc that I hand built that will eat the Pirhana 140 for lunch.
I am no stranger to cheap cc's. I used to bracket race air cooled VW's in my younger days. You could throw a lot of money into a small 1700 cc engine, headwork, balancing, valvetrains, Webers, cam, to get a lot of peak horses at 7500 rpm, that would smoke a 2276 cc motor built with cheap parts that would float the valves at 5000 grand. I also believe a Honda Monkey 125 puts out more power than a Lifan 125 just due to the fact the Honda is fuel injected. I am also quite certain that the 125cc Monkey even puts out more power than my YX 140. My little bike only has the advantage because it is lighter and I am lighter than my son. My 1700 lb Karmann Ghia with its 175 horsepower 2110cc motor has the same power to weight ratio as a 400 horsepower Dodge Challenger.
 

OLD CT

Well-Known Member
OGTMB, The monkey is 9 hsp all stock and heavy by itself. The 140 is close to 12 hsp and light with the CT. So the 140 kit will bring the Monkey to 12 hsp and level the playing field. Check out the graph.
It would be a great match up.
 
Still won't be a level playing field. The Monkey weighs 231 lbs. The CT70 weighs 165, add 10 lbs for the bigger engine and estimate 175. I weigh 175, my son weighs 210. Him on his Monkey weigh in at 441 lb. My on my CT weigh in at 350. I'm 20% lighter, so the 12 horsepower Monkey will need 14.4 or 20% more horsepower to keep up. So either build a bigger motor or lay off the pasta or both. Next time we ride together, we're switch bikes and I'm guessing it will be a dead heat.
 

Deoodles

Well-Known Member
The stock gears on a Monkey make it anemic off the line. It isn’t buzzy with a 14 and the extra torque through all gears is much needed and makes the bike more enjoyable.
You mentioned the new 5 speeds coming out. The gear ratios are tighter but 5th won’t be any more than the current 4th. That isn’t going to make much difference in how it rides other than having to shift more
I replaced my cam, did an intake and exhaust. Put in a new ecu and had a tune. What is the bike faster? Hell yeah at least 10 miles an hour but it was louder and I didn’t enjoy it at all I went back to bone stock changed the front sprocket to 14 and I am happier. It isn’t about TopSpeed it’s about being able to handle the roads you want to ride on. It was an expensive lesson learned. Just glad there are folks that haven’t learned that yet. I was able to sell all of those upgrades and recoup $$$.
The stock monkey runs great it just needs better gearing and 14 works
Last thought; My CT70 with a 124 stroker build has more torque than my Monkey but either one handles the roads I ride. The CT70 is faster. Faster to get up to cruising speeds and the ability to hold higher speeds.
 
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I agree with everything you say, although I have changed the gearing on almost every bike I've owned to give it longer legs, including my belt drive Harley and a shaft drive Beemer (not the simplest project). I have a bucket of 420 sprockets and I'll ask my son if he want to try a 14 on his Monkey. As John Belushi said, "don't cost nuttin" .
 

Deoodles

Well-Known Member
OGWTMB. Don’t miss the point. It wasn’t to have your son change gears it was to point out that A 140 v 125 race has a predictable outcome and isn’t really a contest
 

darrel gunderson

Active Member
Just know that if you change your front sprocket to a 14t it will throw your speedo off quite a bit. I went back to the 15t on mine just for that reason. There is a company that sells a product to re calibrate it though.
 
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