Exhaust and big bore kit questions

[Reyne]

Hi guys, long time reader, 1st time poster.
I'm a new owner of a Motovert RX125. Its an awesome little machine and these forums have some great info for a newbie to the scene.

I'd like get full exhaust for it and am just after some guidance
The Motovert Expert exhaust system looks good, has a 32mm bore and it might even fool the cops into thinking it is standard (is got motovert stamped on the side). My local shop is quoting me about $300 for it. The price seems a little high to me, anyone know where i can get it a little cheaper?

Any other suggestions as far as the exhaust goes?
Are these pretty much the same thing? (bottom left) Carbies & Fuel System

I'd also like to fit a big bore kit. I've found quite a few around the place (ebay, east50's etc) is there any difference in quality between these kits? I guess the most expensive are the ones from the USA (tbolt, sgr racing).
Could someone reccomend any particular one?

Thanks guys

 

[crazy-latin-steven]

I know you can get some big bore exhaust 32mm from ebay for around $100-$150. I think there called H-bomb. Check DHZ Mini Moto on ebay they should sell them.

 

[crazy-latin-steven]

It wouldnt pass db for the road. There pretty loud.

 

[01nutracing]

Regarding the big bore kit for the 125. I spoke with Brian from East50s 2 days ago and was looking at a big bore kit. He told me straight out that it was a waste of time as the so called 138 kit is truly only a 127 or 128. He could have sold me a kit but he was honest enough to tell me the truth. He is a engine rebuilder by trade so I believe him especially when he did himself out of a sale. He said they go a bit better than stock 125 but pretty dissapointing for the price. I couldnt believe how honest and straight forward he was. We need more people like him as it was really good to talk to someone who new their stuff.

 

[spoonta68]

u can go 146cc bore kits
i can supply for 200 delivered
and the exhasut i can supply for #165 brand new

let em know

 

[unit_mx]

G'day mate

I know Eastcoast powersports has on the wall for $220 , its a genuine unit.

However DHZ sell the exact same pipe for half of that minus the Motovert etching

Spoonta has a second hand unit for sale too on here.

They aren't ******** loud so you should be ok

 

[wogtaz ryder]

Regarding the big bore kit for the 125. I spoke with Brian from East50s 2 days ago and was looking at a big bore kit. He told me straight out that it was a waste of time as the so called 138 kit is truly only a 127 or 128. He could have sold me a kit but he was honest enough to tell me the truth. He is a engine rebuilder by trade so I believe him especially when he did himself out of a sale. He said they go a bit better than stock 125 but pretty dissapointing for the price. I couldnt believe how honest and straight forward he was. We need more people like him as it was really good to talk to someone who new their stuff.

What kit are you talking abouuut????? hes talking about the jailing 125 not lifan 138..

Get this kit and try and get a Lifan Big Valve Head (BVH)
hear they RIPP

NEW 146CC TB BIG BORE KIT FITS JIALING 125CC YX 140CC - eBay Other Makes, Bike Parts, Motorcycle Parts, Accessories, Cars, Bikes, Boats. (end time 02-Apr-09 20:29:00 AEDST)

 

[Dabomb]

hey man.... i run the 146 kit with 140cc BVH and a 32mm zorst....goes well no problems.
its loud. so if cops are near/tailing....drop the rpm and you will be sweet!

 

[headsmess]

yeah, i got a dhz pipe...32 mm? 105 bucks when i won it, 150 normally... loud, but i find the wind noise in the helmet is louder not really that bad...
and dhz told me the same thing about a big bore kit...dont bother. MAYBE change the piston though...and do the cams... the cams helped

havent gotten down into doing the piston yet, and yeah, id like a big valve head soon... possibly even a 3-4 valver if i had the dosh. will a yx head fit me lifan 125?

and while my cylinder is STAMPED 124, its actually only 119...grr.... all in the stroke of the crank i guess.

and i passed a cop yesterday... didnt even look at me

 

[Cactus Jack]

and dhz told me the same thing about a big bore kit...dont bother. MAYBE change the piston though...and do the cams... the cams helped

havent gotten down into doing the piston yet, and yeah, id like a big valve head soon... possibly even a 3-4 valver if i had the dosh. will a yx head fit me lifan 125?

and while my cylinder is STAMPED 124, its actually only 119...grr.... all in the stroke of the crank i guess :

Yeah I bought a few of those BBK's , a pipe and a cam too ... but haven't ran anything yet ... My experience with modified XR75's were that the PK 80 kits were better than the 96cc Powroll kit (superior top end revs , less vibration , quicker revving etc) ... a Yoshimura race cam was no good with a stock piston ... but worked great with the high compression 80 pistons ...

The YX 150/160 KLX type heads won't fit a Lifan or Jialing because they have a wider cylinder stud spacing ...

What type of Lifan have you got ... the black non kick in gear 124 OR the start in gear grey 124 aka the Super "125" (both 119.69 cc's ) ...

If your engine has 2 bolt valve adjustment covers then it already HAS a big valve head ... You can buy a TB BVH that has a 30 mm inlet valve and 23.5 mm exhaust valve but they're pretty costly compared to a stocker ...

NEW TB Big Valve Head for Jialing type engines! - Planet Minis

Most people fit a big valve head to their 125 Jialing at the same time that they fit a BBK so they don't really get a good take on what the bore kit alone does ... most of the gain can be attributed to the head ... the BBK WILL punch up the bottom end torque in every case ... but they rob top end revs unless the head is ported out bigger and fitted with bigger valves ...

The "138" bore kits are definitely only 127.1 cc kits (54 mm bore x 55.5 mm stroke) ... The stock 52.4 bore x 55.5 mm stroke "125" Lifans are actually only 119.69 cc so there's just over a 7 cc gain ... which works good with the BVH and allowed them to get away with the "138" scam ...

 

[Poulsen8r]

Not that i doubt you or anything, but i thought the newer lifan motors had a 57mm stroke? This would still only mean 130.54cc displacement not 138cc... I also thought that the BBK was a 55mm piston... This would make it 135cc's...

 

[Cactus Jack]

The 140's (55 mm bore) and 150's (56.5 mm bore) have a 59 mm stroke but they have a 15 mm wrist pin ... The Lifan 120/125/127/138 ALL have a 55.5 mm stroke and run a 14 mm wrist pin ... Jialng 125's run a 57 mm stroke with a 13 mm wrist pin ... The Lifan "138" kit has a 54 mm piston that has a 14 mm wrist pin ... the cylinder is also shorter than the 80 mm cylinder of the 140/150 so you couldn't use one on them without running a thick alloy plate and two base gaskets and boring the pin bore out to 15 mm ... Aside from that ... Why would you even THINK of deboring a 140/150 unless you were building an engine to suit special racing class rules ...

 

[Reyne]

Thanks guys for all the replies.
O.K so as far as I can tell, there's more bang for your buck in getting a BVH rather than a BBK?
I notice there's stroker kits out there aswell, like this sgr-usa.com
Any thoughts on these?

 

[headsmess]

standard old 17mm nut screw in valve covers...and i was peeking at a BVH at "motoXspares"? definitely got the small valve head has that tapered section in the combustion chamber.

mines neither black nor grey but a totally weird checkered pattern love to know how they did that paint job.... that i now have to ruin cause ive cracked the case.

i want top end, im on the road. taking off nice and quick, pulling 80 in third carbies holding me back a bit... im sure its only a 20mm

i actually was going faster with a 16 front than the 17 i got at the moment... able to spin a bit easier i guess... in fourth.

 

[Dabomb]

im runnin the stock carby with the 146 and Lifan BVH on the jialing donk....its so reliable but, after WOT gear changes it bogs, thinking that this is a capacity of the carby problem and it cant supply enough fuel and the bowl has a recharge time period to fill the bowl with fuel again.

 

[DvDRip]

I've seen this a couple times lately, what is WOT?

 

[Poulsen8r]

WOT= Wide open throttle

 

[DvDRip]

lol, so obvious

 

[mini mad]

after a good look at my engine the day i done my blue slip it has 138cm2 on the bottom of the head it pissed me off a bit it was sold to me by a shop as a 140cc lifan.

 

[Poulsen8r]

If its on the head then that size i likely to be incorrect... the same lifan head is used on a variety of different motors so it is possible that your motor is actually a 140... What does it say on the barrel? that will be the actual size.