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Hello Everyone can some one tell me why my mini bike starts but when I rev it the back tire only moves when off the ground!
 

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Can some body help me figure out why I can't get my Coleman CT200u ex Mini Bike started. I found some what looks like water in my engine. It's a milky looking color. Hope it's ok
 

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Can some body help me figure out why I can't get my Coleman CT200u ex Mini Bike started. I found some what looks like water in my engine. It's a milky looking color. Hope it's ok
Those things are not water cooled so how did the water get into the engine?

Go to the auto parts store and rent a compression tester take the spark plug out and put in the compression tester and give it a few pulls if you have less than 70 PSI of compression you're going to need a rebuild or a new engine.
 

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What's your poison? Mine is 40:1
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Compression would be a good start to check, I would also pull the spark plug and pull the pull starter 15 times hard and see if anything comes shooting out with the fuel shut off, by the way. That'll help clean out anything that's in the cylinder. And then I would spray some silicone or brake cleaner in the cylinder before you put the spark plug back in and see if it would fire up for a few sec. Just a couple quick things to check, before you see if it's a total rebuild. In my experience those engines last a long time. I would also check your fuel tank, stick a rag or your finger in there and see if it's some sort of water gas mix.
 

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More than likely it was left outside and that's how water got in.

Once you check the compression and if it's low go ahead and take the head off and see how rusted it is you will be able to assess if it's worth saving don't waste too much time on it since you can buy a brand new predator engine at harbor freight for very cheap...
 

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Those things are not water cooled so how did the water get into the engine?

Go to the auto parts store and rent a compression tester take the spark plug out and put in the compression tester and give it a few pulls if you have less than 70 PSI of compression you're going to need a rebuild or a new engine.
 

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I wanna upgrade my engine anyway. I'll fiddle with the original one later. Could you suggest a engine that will work well for the ct200u ex? I'd like to go faster for sure but don't want to buy a bunch of mod parts to add to new engine to do so. Thanks for your help
 

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What's your poison? Mine is 40:1
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Go to Harbor Freight, buy a 6.5 HP predator. A 212cc. You can either get the Hemi or the non Hemi it really doesn't matter. After you start modding it, it won't matter. There's plenty to do, to upgrade it later. If you want to leave it stock for now you need to take the stock main jet and hand drill it one size up. On Amazon there is a hand drill kit. It will run a lot better. I've been using those engines for a long time.
 

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What would make the compression any less? Thanks
A rust pitted or stuck valve or a rusted or pitted cylinder wall...

Obviously since these engines are air-cooled and there is no water that means that it was neglected. Left outside in the rain or flood damage.
 

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Go to Harbor Freight, buy a 6.5 HP predator. A 212cc. You can either get the Hemi or the non Hemi it really doesn't matter. After you start modding it, it won't matter. There's plenty to do, to upgrade it later. If you want to leave it stock for now you need to take the stock main jet and hand drill it one size up. On Amazon there is a hand drill kit. It will run a lot better. I've been using those engines for a long time.
Would this work?

 

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That 7hp engine is a lot bigger then it looks your going to need a 6.5
 

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I hope I made the right Choice. Hard to find the motor available that you guy's were referring to let alone be shipped to California. This is what I got see link below.

 

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I figured everywhere in the country has a harbor freight but I could be wrong you should be able to drive over to harbor freight and buy this one right they're on the spot no shipping required it's one of the most common ones and has the most possible performance parts go-kart guys love these things I have even seen guys put turbos on these things...

 
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