lifan 110cc with little power

[katoranger]

One more thing. Have you checked the valve adjustment?

[trodirt]

Yep, valves are in spec

[Mudflap]

Many kids ATVs have a restrictor in the exhaust so I'd definitely check that.

[Bruce's]

I play with lots of honda z50-ct70-trail90 bikes and do a fair amount of china swaps as many of the bikes I build become road legal bikes and the riders want them to be quick enough to keep up with traffic .Anyway ,the z50 and ct70 factory pipes are too restrictive ,even with an 88cc kit ,so there is no use for them with the bigger engines .We do use the ct70 china clone pipes (skyteam etc) as they resemble the stock ct exhaust ,they can be bought cheap ,and they are larger so they flow better as many of the china ct70 bikes have 110 and 125cc engines from the factory .Chances are if your bike came with a 50cc engine and you put a bigger engine in it ,you are leaving a good bit of power on the table if you don't have a larger pipe .

[trodirt]

What size exhaust would you recommend? And where would be a good place to get one from?

[Bruce's]

I don't know what bike you are working on so not really sure what you are looking for ,but the skyteam ct70 clone pipe works well on a ct70 ,the fmf pipes work well on pit bikes,xr70,and crf70 ,and most of the pit bikes that are factory 110 and up come with pipes properly sized so even finding one of them is better than nothing .I generally buy problem pit bikes and strip the engines and anything else worth saving and use them to build Hondas for myself and my customers so I have a few around all the time .I also have a proper tubing bender so I can fabricate a custom unit myself easily .I keep all the exhausts from the pit bikes as I might use it down the road on a build or even to just get someone out of a jam .

[trodirt]

The one I have looks like a crf50 Clone to me and it has a 110 on it. If you have an exhaust that would fit it. Would you want to sell it? I'll try and post a pic of the bike

[Bruce's]

I live in northern Ontario Canada ,the shipping from here is stupid expensive ,truly not worth shipping it .Have a look in your local classifieds ,ebay ,craigslist etc and find someone with a dead pit bike cheap and buy the whole thing .Last Thursday ,I picked up a 150cc pitbike with a broken clutch lever for $40.00 ,running and riding in great shape .It has an aftermarket hydraulic clutch system on it so the former owner couldn't find a replacement lever .I just used a pitbike front brake lever upside down and it's working fine and will be installed in a ct70 next week .

[Adjuster]

Is it possible to somehow open up my existing exhaust? My exhaust has a special tab welded onto it for the center stand to rest on in the up position. It also has a triangular bracket on it in the right place to hang from the frame. Is it just a matter of drilling some holes in the end of the pipe? Right now my pipe is about 6" wide at the end with a little 1" hole in the center the exhaust comes out of. The rest of the back of the pipe is welded shut.


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[Bruce's]

The issue is the pipes internal diameter is too small ,pretty much need to replace it with a larger diameter one .

[katoranger]

http://www.ebay.com/itm/EXHAUST-PIPE...909b62&vxp=mtr

[Adjuster]

Kato its hard to tell but that does look like the overall shape of my exhaust except the frame bracket and center stand bracket are missing. I am not much of a fabber but I guess I could figure something out.


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[Weldangrind]

Originally Posted by Adjuster

Now you have me questioning my bike. I had an original 49cc with the 19mm carb. I changed to a 125cc with a 22mm carb. I have never touched the original exhaust. Is this something I need to look into? How can I tell if I need to purchase new or modify my exhaust?

The short answer is plug colour. Do a plug chop at idle, mid range and WOT.

[katoranger]

Originally Posted by Adjuster

Kato its hard to tell but that does look like the overall shape of my exhaust except the frame bracket and center stand bracket are missing. I am not much of a fabber but I guess I could figure something out.


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There are lots of them on ebay, plus other sites. Probably one with the correct brackets out there.

[Adjuster]

Is there any way to feel/tell diagnose if your exhaust is too restrictive?



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