Light mods for the Coleman CT200U-EX

#21
Maybe time to upgrade to a Torque Converter. I just bought a CT200U and the stock clutch on it is less then satisfactory.
It's grabby and the bell wobbles around loosely on the thing. Makes some god awful noises at times. I'll be ordering a TC for it.
From what I gather the TC makes a world of difference in performance.
 

MJL

Active Member
#22
Overall, the clutch seems to be okay. It has a needle bearing instead of a bushing and seems to be a knockoff of a Max Torque design. I don't think I have ever smoked it and I make sure to mix plenty of full speed runs in my riding to allow it to cool;). I only noticed any difference on the steepest hill climbs. My only thoughts are that some grease has migrated from the bearing onto the friction surface or the spring has stretched a bit. I'm not quite ready (plenty capable, though) to make any big changes as far as a TC goes as I don't really need the speed and would just have to slow it down for the kids. For now, I'll just give it a good cleaning and scuff up the friction surfaces.
 
#23
I run a Hilliard extreme duty clutch and although it requires maintenance like the rest it has held up to my built engine pretty well. They are super easy to work on and it takes no time at all to swap out the springs for different engagement points.
 
#24
You know I was looking at the OP's pictures of the stock muffler, so I pulled the one off of the Predator on mine. What the heck were they thinking? You have a large D port on the head, and then a tiny round pipe stuffed into the muffler flange. Talk about restrictive and running lean. That stock set up is causing all kinds of back pressure, so performance on the fuel end can't be optimised with the exhaust plugged up.

If I wasn't installing a header, I'd cut that little elbow off, and install a larger diameter tube, so all the exhaust could flow into the muffler.
 

MJL

Active Member
#25
I cleaned the clutch real well with brake cleaner on a rag and it seems to be grabbing better. Scuffed up the drum some too, but the shoes were so hard the sandpaper didn't do much at all on them. Used more of the white lithium on the bearing but picked up some high temp grease for the next lube. Just got to wait on a new brake handle before we can ride some more;)
 

MJL

Active Member
#26
Also picked up some DuPont Chain Saver lube. Had to replace the front chain as two links were seized. Seemed like all the factory grease slung off at once. Maybe the kids got it hotter on their longer rides than I did on my shorter 20-30 min rides. Seem like the problem came from rounding off the bottom of the links on the chain tensioner. I've been using WD-40 brand Teflon dry lube on the rear chain, which seemed to be working, but wasn't convinced it was sufficient. The DuPont lube looks much better as far as establishing a film.
 
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#27
The links seized on my Coleman also. The factory chain sucks so I suggest replacing the entire chain, front and rear. I didn't have anymore issues after doing so.
 
#28
Also picked up some DuPont Chain Saver lube. Had to replace the front chain as two links were seized. Seemed like all the factory grease slung off at once. Maybe the kids got it hotter on their longer rides than I did on my shorter 20-30 min rides. Seem like the problem came from rounding off the bottom of the links on the chain tensioner. I've been using WD-40 brand Teflon dry lube on the rear chain, which seemed to be working, but wasn't convinced it was sufficient. The DuPont lube looks much better as far as establishing a film.
How's the tensioner look? I ask because mine has very little time on it and the chain already wore it down to metal. When I spun it, it sounded like it was full of gravel instead of bearings. The jackshaft bearings weren't much better. I pooped the seals off of the bearings and saw little lube and lots of rust. Glad I'm going with a TAV.
 
#29
How's the tensioner look? I ask because mine has very little time on it and the chain already wore it down to metal. When I spun it, it sounded like it was full of gravel instead of bearings. The jackshaft bearings weren't much better. I pooped the seals off of the bearings and saw little lube and lots of rust. Glad I'm going with a TAV.
I use Dupont chainsaver.it's good stuff.buy good chain too like RK. [MENTION=58247]MJL[/MENTION] . .Yeah i just pulled my original engine off my ct200u..i got the 212 hemi and a tc waiting..:smile:
 
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MJL

Active Member
#30
How's the tensioner look? I ask because mine has very little time on it and the chain already wore it down to metal. When I spun it, it sounded like it was full of gravel instead of bearings. The jackshaft bearings weren't much better. I pooped the seals off of the bearings and saw little lube and lots of rust. Glad I'm going with a TAV.
My tensioner appears to be solid metal and has a couple shallow groves in it after maybe 10 hours or so. I'm really jonesing for a Chinese TC but I have the 5/8 shaft, so I'd probably choose to swap the crank as I don't need a spare motor. I'd still need to dial it down a fair bit for the kids. They caught me popping a little wheelie today and I can already see the glimmer in their eyes! How well does a TC respond to the throttle limit screw? I'd like to keep them down to 15 mph or so...
 
#31
Well more money, but gopowersports offers a TAV for the 5/8" shaft on the CT200U.
https://www.gopowersports.com/coleman-ct200-series-torque-converter-kit/

If you have the engine speed dialed down the TAV will stay in low gear. So low speeds, but wheelie capable.

Whoops! almost forgot, OldMiniBikes is working on one also for the 5/8" shaft, not out yet but hopefully soon. From what I've read on it, it's not going to require jacking up the engine or cutting off the bottom of the TAV plate to fit, and not having to remove the chain guard front mount.
 

MJL

Active Member
#32
Picked up a 2015 Baja (camo with green frame) today. Probably overpaid, but it was the closest one. I'll be ordering a TC soon;) The minibike madness is setting in!
 
#34
Picked up a 2015 Baja (camo with green frame) today. Probably overpaid, but it was the closest one. I'll be ordering a TC soon;) The minibike madness is setting in!
Nice score..goes easy on a Baja with only cutting a bit off tc plate and you will need a 5/16x24 fine bolt for the engine and mounts...:thumbsup:
 

MJL

Active Member
#35
Worked on the Baja a fair bit today. Changed the oil, pulled the clutch to measure the shaft just to be sure, went ahead and cleaned the clutch and oiled the bushing while I had it off, replaced the missing master link on the short chain, lubed the chain, and adjusted the throttle cable to get it to open all the way. I don't think the previous owner ever had full throttle! Although, they really didn't need is as all they did was make laps around a 1/4 acre lot. Went ahead and threw in a 140 tube with the stock jet. Hit a road block though when I couldn't get the brake adjusted. I pulled the rear drum to inspect and found separated brake lining. Ordered a cheapie set of shoes off of Amazon to get it going, but also ordered the Honda shoes off of e-bay.

I did put everything back together enough for a little test ride around the yard. Can't compare performance fairly to the 200 EX as they are geared differently, but while strong, the engine certainly doesn't seem to have the thump of the lightly modded 200 EX (yet!). While similar to the Coleman at first glance, the Baja is quite a bit different design. The riding position and handlebars are much more upright resulting in a very different feel. I haven't measured, but the wheelbase might be a touch longer on the Baja as well. Once I get the brake shoes on, I'll do a top speed run just to see what it can do with the stock setup, but that won't last long as I have torque converter (OldMiniBikes), spare belt, and proper lug nut ordered;)
 
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#36
[MENTION=58247]MJL[/MENTION] yeah the Baja is a little bigger,nice to have something different..:smile: I think the ex is about same wheelbase as ct200u..
 
#37
If I was just doing a 31 or 33 jet and a timing key I would just use a 1/32 drill bit on the jet and file the key. I modded my stock air box using a brigs 9/13 HP air filter. It sticks out the top of the lid and I like how it looks. If you want to bypass the muffler take the shield off and drill out the plug that's in the middle of the pipe. If you look at were your exhaust pipe enters the muffler at the bottom, it just goes straight up and is welded and plugged at the top. It will be loud but will just flow through and bypasses the internals of the muffler.

air filter mod 2.jpg

Here is my modded filter.
 
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#38
I had also bypassed my governor by chopping a few coils out the return spring and was running about 5K which was about 28MPH. When I pulled the stock rod to put a flat top piston in it, it had some scuff marks on it so I swapped it with a spare BSP rod and set it down to 4K using the throttle stop screw. I am new to these motors so don't know what normal wear and tear look like but the motor was only 1 hour old and the governor had been bypassed for 30 minutes of that. If you want to get a little extra out of your bike you can chop a few coils and raise the RPMs a little. I think 4K is pretty safe on stock internals. The instructions for my bike said not to exceed 3900 RPM so 4K should be fine. Just down load a GPS speedometer with max recall. You should be shooting for just under 23 MPH. 23 should be Ok but that will be about 4100 RPM. The stock rods don't lubricate well at high RPM so I would not push it past this tell you get a billet rod and new flywheel.
 
#39
Hello. This is my first post. Very much enjoyed reading through this thread. Got a question. I just bought a new CT200U-EX from Tractor Supply. Rode it here in Central Colorado up a fairly steep and sometimes rocky trail. Started at 9K and ended at 11K. I'm new to the whole mini bike world. It felt safe and stable and seemed to climb well. However, I found myself needing to ride-push my way uphill a few times (I stayed seated). I weigh 160 lbs and wore a 20 lbs pack. Are there any mods I should do to improve the ride? Quiet is important to me. Thank you.
 
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