Hello, I've got a Coleman ct200u with the stock clone engine. I added a .035 rejet kit, hi-flow air filter and ARC racing adapter. Also have a custom straight pipe. I feel that I need some more power, for what i'm doing with the minibike. My friend did a pretador swap and now he almost beats me, so I need to outrun him next time. Any good recommendations on easy/less expensive upgrades? Thanks!
More power!!
- Thread starter CDM
- Start date
- Tags clone engine performance mods power
Your going to need more RPM or more gearing. Maybe you could change the driven gear on your clutch to one with more teeth. I think the colman uses a 10 tooth clutch. I would try swapping to a 12 tooth clutch there about $35. You will need to buy a new chain if you do this obviously as well. Should add about 5 MPH to your top speed.
Another good mod although starting to get more expensive would be a GX160 aluminum flywheel or the PLV aluminum. You could also pull the flywheel, file the key and run some higher octane fuel. The timing and compression on this motor is for 87 regular pump. You could pull the head and try lightly porting it your self. I did a light clean up of my port on my head and it was a lot easier than I thought it would be. Some 1.3 rockers are only around $17. I don't know what all is involved to run them like if they work with the stock springs or not but might be worth looking at.
Follow my advice at your own risk......
Remove the flywheel then remove the flywheel key then reinstall the flywheel and line up the keyway slots then rotate the flywheel a little less than 1/2 the thickness of the key slot in the direction of operation. Now reinstall the nut and and torque it to factory specs. Check to make sure the wheel stayed where it was supposed to. And your done you have just advanced your timing now it won't run so retarded :laugh:
Remove the flywheel then remove the flywheel key then reinstall the flywheel and line up the keyway slots then rotate the flywheel a little less than 1/2 the thickness of the key slot in the direction of operation. Now reinstall the nut and and torque it to factory specs. Check to make sure the wheel stayed where it was supposed to. And your done you have just advanced your timing now it won't run so retarded :laugh:
Look up how to grind your rockers for more lift. Not sure if you will notice any power from it but I know racing people will file rockers and you can decrease or increase lift by grinding in different spots. If you grind on the tips were they ride at full lift you lower lift but if you grind in the center were it rides at closed it will increase the lift. Not sure how far you can grind and have not done it but its free. I would ask some people with experience with this and see if it is worth doing.
This is why I recommend a GX160 flywheel or the PLV. You can pick up a GX160 for around $40 and it advances your timing 5*. You may not see much from timing but your at a point were your not going to get much tell you can remove the governor. Its holding back an extra 3 HP. Your at the point that its time to start opening the motor to get more out of it. You buy a flywheel it will be lighter, advance timing, dose not require you to open motor and is one of the mods needed to remove the governor so it puts you that much closer to being able too.
One thing you could do that will add power every were with out taking off the governor is to replace the head with a 14cc head. There about $30 for a bare head. It will raise compression a lot. You should be able to transfer all your parts to the new head. You would have to lap the valves in. I have a UT2 head which has a 18cc chamber and has a larger valve than stock. Stock intake is 25mm and the UT2 is 26mm. You have to run the UT2 intake valve in it but every thing else stock can be used. The UT2 will flow better than stock and will add about 1 point more compression and put you in the high 8s. The UT2 heads are not cheep though and you might as well get a flywheel for the price and start down that road. Your stock compression is in the mid to high 7s right now. You can also just swap the piston out to a flat top which will raise compression about the same as the 18cc head for cheep. Flat top piston is about $20 plus the gaskets you need to put the motor back together.
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DeadPixel... For the stock Coleman with it's 10 to 1 final drive ratio you would need well over 6K of RPM's to get near 40 mph. Also, peak HP on a clone with his current mods would be in between 4300 and 4700 RPM's. Not long after that the power drops off and valve float sets in. Those numbers are from a few articles I have read where they rejetted stock clones, gave them more air and dyno'ed them.
A lot of people are installing TAV's on the Colemans because they want more top speed. Governed with the throttle stop screw all the way out the top speed is around the 25mph range. This already takes the RPM's into the "you better get a flywheel and rod" area.
A lot of people are installing TAV's on the Colemans because they want more top speed. Governed with the throttle stop screw all the way out the top speed is around the 25mph range. This already takes the RPM's into the "you better get a flywheel and rod" area.
I have a Pred 212 that I reworked similar to what you did plus I put in a mild cam and 18lb springs. It is a CL-2 and I put on a ARC billet flywheel.
WOW. Big difference in power from stock. That cam isn't even supposed to be that good but it made a difference. There are plenty of cams you can get for not much money. Mine was $12 used... I also disabled the governor to let it spin faster. You can get a tach and watch the rpm. I heard not to go over 6000 with a stock rod.
With 10:1 gearing and a governor your not going to get much top end. When you hop up a Predator you get a lot more torque and can change your gearing to take advantage of that. I'd shoot for about 7:1 to still retain some out of the hole grunt and gain some top end.
The problem is once you start modifying the engine, you are always going to want more power, then more power ... etc...
Have fun
Danford1
WOW. Big difference in power from stock. That cam isn't even supposed to be that good but it made a difference. There are plenty of cams you can get for not much money. Mine was $12 used... I also disabled the governor to let it spin faster. You can get a tach and watch the rpm. I heard not to go over 6000 with a stock rod.
With 10:1 gearing and a governor your not going to get much top end. When you hop up a Predator you get a lot more torque and can change your gearing to take advantage of that. I'd shoot for about 7:1 to still retain some out of the hole grunt and gain some top end.
The problem is once you start modifying the engine, you are always going to want more power, then more power ... etc...
Have fun
Danford1
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I have a Pred 212 that I reworked similar to what you did plus I put in a mild cam and 18lb springs. It is a CL-2 and I put on a ARC billet flywheel.
WOW. Big difference in power from stock. That cam isn't even supposed to be that good but it made a difference. There are plenty of cams you can get for not much money. Mine was $12 used... I also disabled the governor to let it spin faster. You can get a tach and watch the rpm. I heard not to go over 6000 with a stock rod.( Also from what I heard the CL-2 cam won't spin up that far).
With 10:1 gearing and a governor your not going to get much top end. When you hop up a Predator you get a lot more torque and can change your gearing to take advantage of that. I'd shoot for about 7:1 to still retain some out of the hole grunt and gain some top end.
The problem is once you start modifying the engine, you are always going to want more power, then more power ... etc...
Have fun
Danford1
WOW. Big difference in power from stock. That cam isn't even supposed to be that good but it made a difference. There are plenty of cams you can get for not much money. Mine was $12 used... I also disabled the governor to let it spin faster. You can get a tach and watch the rpm. I heard not to go over 6000 with a stock rod.( Also from what I heard the CL-2 cam won't spin up that far).
With 10:1 gearing and a governor your not going to get much top end. When you hop up a Predator you get a lot more torque and can change your gearing to take advantage of that. I'd shoot for about 7:1 to still retain some out of the hole grunt and gain some top end.
The problem is once you start modifying the engine, you are always going to want more power, then more power ... etc...
Have fun
Danford1
Yeah. All those HP parts are nice, but to me, the interesting thing is 2 Coleman's racing with different engines. I may just put my second Coleman together with the exact minor mods as the first, but with a nos Greyhound engine. Then do a 0 to 25 drag race with my son. It would be Hisun versus Greyhound. I think it would be neat to see if there are any performance differences between these nearly stock engines. The Greyhound has been waiting 7 or 8 years on the shelf for this.
So I found a 38 tooth sprocket that says it will fit the CT200. Stock rear is 50. You will loose some climbing power but gain top end. Right now your gearing is about 10 to 1 and the new gear would put you I think at 7.6 to 1. Its only $29 plus a longer chain and chain breaker.
Rear Sprocket #420 38th Bolts Cross c/c=80 ID=40mm Fits Many Hammerhead TrailMaster + Other ATVs-GoKarts-Minibikes [815512] : Get 2 It Parts, LLC, ATV, Scooter, Go Kart, Dirt Bike and Moped Parts
This should add a few MPH to your bike and looks like the cheapest way to gain speed. I tried to find a clutch with a higher tooth count than a 10 tooth but only found a 11 tooth and it was over $100. Might as well get a torque converter for that price. Your going to loose some performance off the line but gain in the top end.
Rear Sprocket #420 38th Bolts Cross c/c=80 ID=40mm Fits Many Hammerhead TrailMaster + Other ATVs-GoKarts-Minibikes [815512] : Get 2 It Parts, LLC, ATV, Scooter, Go Kart, Dirt Bike and Moped Parts
This should add a few MPH to your bike and looks like the cheapest way to gain speed. I tried to find a clutch with a higher tooth count than a 10 tooth but only found a 11 tooth and it was over $100. Might as well get a torque converter for that price. Your going to loose some performance off the line but gain in the top end.
H3441 - Hilliard Extreme Duty Centrifugal Clutch. 3/4" bore, 10 tooth, 40/41 chain | Go Kart & Mini Bike Parts | MFG Supply
Another part I found that might be a good upgrade later. You can tune it so it engages at the RPM you need. You can rebuild them too.
Another part I found that might be a good upgrade later. You can tune it so it engages at the RPM you need. You can rebuild them too.