I want to bore my engine but...

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Pitbikerider

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Montreal, Quebec, Canada
Okay so i'm new here, i'm john and a proud owner of a pitbike.

Anyways, i would like to bore out my engine.
The engine is a Loncin 125cc (124 writen on the cylinder). The engine is pretty much the same as a Lifan 125 cc. The engine is Non start in gears.

So my questions are
- Will a big bore 138 cc designed for a lifan fit on my engine?
- Besides the cylinder, would anything else need change in order for the big bore to work? (yeah i'd need an oil cooler i know)
- Will i gain alot of power?
- Also, where could of buy some kits? could you guys show me good kits please.

Here are some pics of the pitbike

Thanks for the help guys.
 

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hey lad, welcome to mini riders. hmm I haven't had much to do with china engines over my time but, check dhz for the money you will pay for a big bore KIT you will be prob better off to get a hole new motor. like a yx 140 brand new oil cooled and all noo trouble if you have same as crf mounts should bolt write on and you will prob need a bigger carb ect. well anyways hope i help some ppl may have diffrent opinions and they also should be taken into consideration. ebay type DHZ or follow the link from our site as they are a proud sponsor or mini riders.
 
mboyg1 said:
hey lad, welcome to mini riders. hmm I haven't had much to do with china engines over my time but, check dhz for the money you will pay for a big bore KIT you will be prob better off to get a hole new motor. like a yx 140 brand new oil cooled and all noo trouble if you have same as crf mounts should bolt write on and you will prob need a bigger carb ect. well anyways hope i help some ppl may have diffrent opinions and they also should be taken into consideration. ebay type DHZ or follow the link from our site as they are a proud sponsor or mini riders.
Click to expand...

Okay thanks. The carb is already a 28mm so i won't be changing that. I could probably be better off with a new engine, but i'm not sure i want to spend 400-500$ for an engine... i was thinking getting an inner rotor kit with a supercoil... But i know i want either a big bore or a new engine. Money isn't a problem, just unsure i want to spend that much just for an engine and be stuck with a 125 cc engine that i probably won't be able to sell.
 
Okay i find this engine here, a YX 160 and it comes with an IRK, lightened oil slinger, High rev CDI box.

It would come to around 410$ US. Should i go for that !? Seems interesting.

sgr-usa.com
 
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Pitbikerider said:
What do you mean its boring enough as it is? Its a 125... You think its already bored out to a 138?
Click to expand...

hehe sorry dude bad joke... must be funnier when your drunk... got a good laugh here and one more thanks to dvdrip (cheers mate +reps lol :D)

boring - you know mate
–adjective
causing or marked by boredom: a boring discussion; to have a boring time.
 
ando said:
hehe sorry dude bad joke... must be funnier when your drunk... got a good laugh here and one more thanks to dvdrip (cheers mate +reps lol :D)

boring - you know mate
–adjective
causing or marked by boredom: a boring discussion; to have a boring time.
Click to expand...


Yeah i realized once i reread your post lol. Got up early for work today so...

But what about that YX160 engine i showed on my post above? Good idea or you guys have better for around the same price ?

Or should i get my 125 a big bore and an IRK and an oil cooler? Because it will save me cashg to get it bored out, but getting a new engine will probably get me more power and just a better overall. Would a 160cc be to big for my bike ?

Edit : Found this one TBolt USA, LLC » Engines » Piranha Engines » EVOS /YX 140cc Engine
Its 20cc smaller, but i could have the oil cooler with it and with shipping it would come to the same price as the 160 but with an oil cooler of more...

So what should i go for? 140 IRK + oil cooler 400$ or 160 IRK 400$ !?

Can't decide lol.
 
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dont go IRK at all.... but 140~160 is a much better option than any "125" thats really a 119cc with no room for boring out at all...
 
personally i say new engine hands down, and depending on other factors, style of riding etc. will factor into the choice of size 140-160...

if you are looking into yx motors look at the pic below (my yx150) and notice the shape of the top of the engine at the top mount point, there has been a few threads people have made when their yx donk didnt fit under the frame at that point only allowing two of the three mounts to fit so perhaps a lifan would solve that problem rather than a yx.

IMAGE_027.jpg


cant think of any other possible issues atm... bit early still :p

oh and make sure you get a manifold with it if you grab the yx... and you might have to check which bend of exhaust you need... anyway going ridin!! i'm outta here.
 
get a big bore if you want but be readly to pay alot of $$$ when the gear box is dead I wanted to get one for my motovert 125 but the guys said get a bore big but get only 3 rides out of it in till the gear box sh!ts it self.
so im getting a new motor when the motor blows up.
 
Yeah i'll get a new engine just not sure exactly when. I'm thinking the Evo 140 would be my best bet since it will fit on my frame and with an IRK in it, i'd probably have enought power for my liking.

With a 140 like the evo, would the stock exhaust fit on it? I hope so lol or else i'll be modifying it or something lol.

So if the yx150 is problamic for some people, i think i'd have even more problems in size with 160 since its an yx. But i should be good with the 140 evo right ?

But why did someone say no IRK at all??
 
why no irk? i guess it is mostly a matter of choice, but theres more than enough references made by cactus jack(as well as others) about why they ARENT the ducks guts....and, im inclined to agree... having 2 lifan 140's to compare, one with and one without... but otherwise identical

they dont really affect the overall "top end" speed. they just get there faster due to the reduced weight.
the reduced weight of the flywheel, in turn, lowers torque. so you wont hold the high revs under load(uphill in 4th) with an irk. (power is only torque multiplied by rpm...lowering torque also lowers power)

then theres the "dampening" effect the stock flywheels have on crank pulses, which then places less demands on the gearbox, shafts, etc....

also. you gotta keep the things revving else theyll stall... no low speed trials riding...:(

and yes, any shop will try to sell them to you, and glorify how much better they are...but then, its money in their pocket, isnt it? and very few pit bike sellers actually ride, let alone race....its all business, and thats it.

only benefit? theyre simple to wire. and have variable timing (and if you burn out the cdi box, guess what? you have to buy a complete unit again....noone sells just the box seperately. well, not by mail/ebay anyway)

just my opinions...dont have to agree :)
 
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So then what do you suggest ? Because i'm mainly most of the time flooring my pitbike... I surely don't want to stock flywheel as they are oversized. Maybe an outer rotor?

What if i have an IRK with a super coil? Would that help a bit for the loss of torque at low speeds?

I'm so unsure what i should get... The YX160 or the Evo 140. The evo will probably be cheaper. At around 400-425$ including shipping an an oil cooler.

The YX160 will probably be 400$ including shipping but no oil cooler. Though i was told from SGR-USA that i could get a deal... Okay sure but i'd need to buy alot to get a good deal and i'm not sure i want to go over 500$ for a new engine. If i could get a deal around 400-425$ for it with the oil cool, i'll be very interested. Though, i still don't know if the engine will fit on my bike or not...

thanks for helping guys.
 
Just go with a Lifan 150... You wont have any issues with frame clearance, exhaust port matching where the header pipe slips in, and there are plenty of power upgrades available.
 
Well i was told that the 160 would fit, but i'd need a new pipe, so screw that. Its either the 140 evo or this one 155 Z crate. This one would fit no problem, so will my exhaust.

So i'll see the deal i could get for both and i'll chose from there.

Today i went riding and somehow, my front brake hose got chewed up by the tire and now i need a new one... More money to spend -.- How the fk did the hose get caught up in between the fork stanchion and the tire... I've ridden this thing countless amount of times and that never happened...
 
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