Crower G2 And 145 big bore

[kart_ss]

Would these two mods on a lifan 125 make a big diff in preformance? Im going to port it and build up the port floor. Also want to know about valve life with the crower g2?

Is there any stainless valves kits with springs retainers and keepers, and HD Valve springs available?

Also, there only two springs in these heads as there is only 2 valves? Im still learning about these Ohc motors, so im not to sure.

 

[epod]

Akunar

G'day mate. Goto Akunar.com for everything you need. I just bored my lifan 127 to 134cc 55.5mm high comp piston and hight lift race cam. I am still running standard valves and springs with no problem. Tell em David D sent you.
Ride on.

 

[Mack]

Your obviously looking at a tboltusa kit? Hell yeah it'll make a difference! THe crower cam can be run with stock valves and springs.The valves have a good life , but are cheap as chips if you need to replace anyhow. There is an outer and inner spring for each valve.

 

[kart_ss]

Your obviously looking at a tboltusa kit? Hell yeah it'll make a difference! THe crower cam can be run with stock valves and springs.The valves have a good life , but are cheap as chips if you need to replace anyhow. There is an outer and inner spring for each valve.

Awesome. Guess ill run the stock springs then.

Im still kinda worried that you say the valves have good life. Honestly I will probably wont disamble the motor for a long time, and when i do itll be for a valve job and new rings etc.

My buddy has a 1 and half year old lifan that he rides basically everyday, and we have done nothing except check valve cleareance, cahnge oil, and clean and re-oil air filter and it runs like a bat outta hell.

So how long will the stock valves last anyway? Give me a situation that you would compare it to.

Thanks in advance.

 

[kart_ss]

I dont wanna drop a valve and destroy the whole thing!

 

[Mack]

Well because your using stock springs, the valves are not under any extra spring pressure than normal so should have a similar life. I would go up in spring pressure if you modify the engine enough that it really starts to want to rev.

 

[themountain]

Awesome. Guess ill run the stock springs then.

DON`T DO IT!!! You spend a hell of a money on all and you will spare on some 20 bucks parts??? DON`T

 

[kart_ss]

Well because your using stock springs, the valves are not under any extra spring pressure than normal so should have a similar life. I would go up in spring pressure if you modify the engine enough that it really starts to want to rev.

I understand what your saying. Im just really afraid , because i had a full modifed honda gx200 making about 17- 20 hp. I was running stock valves with big spring pressure and a 290 lift cam. The valve went right through the head, and destroyed a huge percentage of the motor.

Does anyone make stainless valves retainers and keepers kit with spring i can install and not worry about mushrooming or breaking the valve. Come to speak of mushrooming a valve tip, had a buddy on a briggs 6.5 modifed motor burn up an exhaust valve because of the same reason on my honda.

Would a good lap job seal up the valves good on these heads?

 

[Mack]

Yes the valves respond well to recutting and lapping. As for stainless valves, I haven't found a source of drop in stainless valves yet. You have to have some blanks turned to suit. I don't think its worth it personally, unless you have a lot of time and money invested in your motor and the thing is built to rev.
The G2 cam is not a big cam by any means. The new Lifan 140 has as much lift in stock form on the exhaust valve....

 

[kart_ss]

would i have to re jet the carb with the extra cc's which puts a little more demand on the carb? Its a 24mm, and the valves are 27/23

 

[kart_ss]

Yes the valves respond well to recutting and lapping. As for stainless valves, I haven't found a source of drop in stainless valves yet. You have to have some blanks turned to suit. I don't think its worth it personally, unless you have a lot of time and money invested in your motor and the thing is built to rev.
The G2 cam is not a big cam by any means. The new Lifan 140 has as much lift in stock form on the exhaust valve....

Does anyone sell different angle valve seat cutters, like a three angle kit or something for these head.

How often should i check my valves out?

And will i have to rejet?

 

[kart_ss]

Does anyone sell different angle valve seat cutters, like a three angle kit or something for these head.

How often should i check my valves out?

And will i have to rejet?

Soory for all the questions, i just really wanna be sure i do it right.

Do I need a high volume oil pump?

 

[Mack]

Yes you can buy your own valve seat cutting kit, but its a lot cheaper to get someone to do it. No you don't need HV oil pump 'cause these are built with one to begin with. Yes you need bigger carb. No you shouldn't need to check valves all that regularly.

BTW- don't ever worry 'bout too many questions, its the only way to learn things....

 

[kart_ss]

Yes you can buy your own valve seat cutting kit, but its a lot cheaper to get someone to do it. No you don't need HV oil pump 'cause these are built with one to begin with. Yes you need bigger carb. No you shouldn't need to check valves all that regularly.

BTW- don't ever worry 'bout too many questions, its the only way to learn things....

Thanks for info mack,

Would a 24 mil keihin be good, i was reading on planet minis forum that a 24 is a good bottom end set up if jetted properly with this setup.Since i already have a 24mil stock set up on this bike.
Is this true?

 

[Mack]

Hey I hope you live in the states...otherwise, what the hell ya doin up at 5 in the morning!

If it's a genuine keihin it would not be too bad, but if you install a BBK then a vm 26 mikuni will be better IMO.

 

[kart_ss]

Hey I hope you live in the states...otherwise, what the hell ya doin up at 5 in the morning!

If it's a genuine keihin it would not be too bad, but if you install a BBK then a vm 26 mikuni will be better IMO.

Lol yea im canadian. You wont find me up that early too often.

Thanks for the info