Ct200u talk

Brandonmcgier192

Brandonmcgier192

New Member
#1
#1
Added some new parts to the ct200u. Aluminum flywheel, billet rod, mikuni vm22 with 120 jet, gov removed, 40t sprocket, torque converter.
The bike only reaches 40 mph, the same as before I modified the bike. Anyone know why this could be? I’m looking to try to get it to 50mph for street riding.

-Brandon
 
sparkwizard

sparkwizard

#2
#2
I would try the stock sprocket with the torque converter.
Your smaller sprocket might not be allowing the converter to shift up.
What RPM was it turning at top speed?
50 is going to take a lot of attention to details, like tire pressures and some more tuning. It is not always as easy as swapping parts. Be patient and try changing one thing at a time.
 
Strigoi

Strigoi

#3
#3
A stock CT200U does not top out at 40mph. I had one, it was slow as shit. Did a small tire conversion with a bunch of mods and now it's running right around 60mph. Going with a smaller sprocket doesn't always mean it will be faster. I had a drag bike that was faster with a 65t rear than it was with a 53t. Even with 20+hp, that bike couldn't pull the RPMs with that 53t on it.

Why didn't you do a small cam? You did the billet parts and bigger carb. You were already in there so it wouldn't have been any extra work.

Pics of mine attached. I think the only thing not changed or modded on it is the footpeg setup. Not even sure you could really call it a CT200U anymore.
 

Attachments

Brandonmcgier192

Brandonmcgier192

New Member
#4
#4
Strigoi said:
A stock CT200U does not top out at 40mph. I had one, it was slow as shit. Did a small tire conversion with a bunch of mods and now it's running right around 60mph. Going with a smaller sprocket doesn't always mean it will be faster. I had a drag bike that was faster with a 65t rear than it was with a 53t. Even with 20+hp, that bike couldn't pull the RPMs with that 53t on it.

Why didn't you do a small cam? You did the billet parts and bigger carb. You were already in there so it wouldn't have been any extra work.

Pics of mine attached. I think the only thing not changed or modded on it is the footpeg setup. Not even sure you could really call it a CT200U anymore.
Click to expand...
I’m looking to get smaller tires for it, any that you recommend?
 
Strigoi

Strigoi

#5
#5
Brandonmcgier192 said:
I’m looking to get smaller tires for it, any that you recommend?
Click to expand...
Staying with the stock wheels? No.

I went down to 6" wheels on mine (hence the "small tire" mod) and it was not a bolt-on mod. Welding/fabrication was required for the rear brake. Luckily I have a friend that can do that stuff.
 
Brandonmcgier192

Brandonmcgier192

New Member
#6
#6
Also, how do you mount the custom gas tank. The stock one sucks and leaks gas from the cap so I definitely want to get a custom one but am unsure of how to mount it onto the frame.
 
SAS289

SAS289

Well-Known Member
#7
#7
40 is not bad if it's a 196 and that's all you did. Because of the gearing the RPM is so low your carb never has a chance to provide any gain.

As part of your progression, you may want to go right to a Juggernaut driver for the torque converter. Most everyone likes the Juggernaut because of the large gearing change. You will see higher RPM and may get more road speed. A nice side effect of the gearing change is longer belt life if pully alignment is set up well. It would work ok with the 40 tooth.

I use the stock driver and sprockets for higher RPM. I like 9/60 gearing. I can get the RPM to give the low lift economy cams I use a chance to start working. I wouldn't get a cam to run less than 3800 RPM with stock gearing. I would just stay with a "stage 1" stock engine for that.

One of my 196's tops out right at 5K RPM. The only real performance parts in it are a CL1 cam and Champion rockers. The 224 I have which is a fairly mild build tops out at 5600 RPM with the 9/60 gearing. The 224 powers well right through the belt shift at 4600 RPM. The 196 struggles a bit belt shifting at 4500 RPM. And all done with very low tire pressure I use for off road. They would be a bit faster on the road if I put air in tires.

All that is just a couple examples of what gearing can do with engines that aren't that powerful.
 
Strigoi

Strigoi

#8
#8
Brandonmcgier192 said:
Also, how do you mount the custom gas tank. The stock one sucks and leaks gas from the cap so I definitely want to get a custom one but am unsure of how to mount it onto the frame.
Click to expand...
On mine it required welding new mounts for it.

GoKartsUSA does offer a cylinder style tank that mounts to the engine. I don't know if it will fit a CT200U. I haven't personally tried it nor am I a fan of them as a seller. They're local to me as well and I won't use them. It is a potential option for you though.

https://gokartsusa.com/Little-BadAss-Minibike-Gas-Tank-7-Inch-Cylindrical-1.aspx
 
Brandonmcgier192

Brandonmcgier192

New Member
#12
#12
Changed back to a 50t sprocket but only reached 38 mph, 2mph less top speed than the 40t. Also it appears that the new exhaust gasket I installed 2 days ago has already gone bad and is leaking air causing backfiring. Any reason as to why the gasket could already be bad or is it just a faulty one.
 
H

hermans13

Active Member
#15
#15
Can you provide a photo of the exhaust header from the gasket flange to the muffler or tip of the pipe?
Also, how long is the complete exhaust system and the diameter?
 
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