Go Back   ChinaRiders Forums > Technical/Performance > Dual Sport/Enduro
Register FAQ Community Calendar Today's Posts Search
Reply
 
Thread Tools Search this Thread Display Modes
Old 10-24-2018, 07:02 PM   #1
crackerjac   crackerjac is offline
 
Join Date: Sep 2016
Posts: 104
167FMM mods

Picked up a wrecked dirt bike the other day with a good motor. 167FMM (229cc OHV). I'm thinking of replacing the OHC 223cc (Honda 230F clone) motor in my bike for the heck of it, not really gaining much cc or HP but why not.


Question, what's the best mods to make with these 167FMM motors? Is there any other motor that the piston and cylinder can be swapped over to increase the cc's? Like the 171FMM air cooled? I'm probably way off in left field with that but there seems to be so much Honda CG clones and variants.


I saw a motor online that looks identical to the 167FMM but was a 172FMM and used in Russia and Europe??? Same engine bigger bore? I can't find much info in them though.


 
Reply With Quote
Old 10-25-2018, 07:53 AM   #2
Mudflap   Mudflap is offline
 
Join Date: Sep 2014
Posts: 1,929
As a rule I wouldn't trust engine numbers as they relate to displacement. The 171FMM engine in my old quad was actually a 163FML by my own measurement. Years back someone replaced a CG engine with a CB and reported no real power difference, but that was on a Lifan 200.


 
Reply With Quote
Old 10-25-2018, 10:51 AM   #3
Weldangrind   Weldangrind is offline
 
Weldangrind's Avatar
 
Join Date: Mar 2009
Location: Sardis, BC, Canada
Posts: 25,977
Agreed. You'd need to pull the head first and measure to see the actual bore, wrist pin diameter and stud spacing. Once you have that, you can search Taobao for a larger cylinder that matches the stud spacing and wrist pin diameter. If you find a match, please let us know.
__________________
Weldangrind

"I figure I'm well-prepared for coping with a bike that comes from the factory with unresolved issues and that rewards the self-reliant owner." - Buccaneer


 
Reply With Quote
Old 10-25-2018, 12:48 PM   #4
crackerjac   crackerjac is offline
 
Join Date: Sep 2016
Posts: 104
I'll do some research when I have a minute. I wish the OHC 223 I have was a true 169FMM (230cc) like the tag rather than the 223cc (crf230F clone) that it is. I found a few upgrade size cylinders for the true 69mm bore version. :(



That said, these OHV pushrod 167FMM motors don't have too many options. The big bore kits they used to sell are no long available from any of the distributors I've contacted. Oh well, I'm just having fun tinkering.


 
Reply With Quote
Old 10-25-2018, 01:47 PM   #5
crackerjac   crackerjac is offline
 
Join Date: Sep 2016
Posts: 104
Interesting, the Zongshen 170mm/SB250 water/air cooled motor (70mm bore) looks to be a converted 167FMM style motor..... swap the head, use an external pump to pump fluid through it... just thinking out loud. I can get the SB250 cylinder kit cheap.


https://www.alibaba.com/product-deta...5e6830fcrlbSH5


 
Reply With Quote
Old 10-26-2018, 02:57 PM   #6
Megadan   Megadan is offline
 
Megadan's Avatar
 
Join Date: Apr 2017
Location: Omaha, NE
Posts: 8,110
Quote:
Originally Posted by crackerjac View Post
I'll do some research when I have a minute. I wish the OHC 223 I have was a true 169FMM (230cc) like the tag rather than the 223cc (crf230F clone) that it is. I found a few upgrade size cylinders for the true 69mm bore version. :(



That said, these OHV pushrod 167FMM motors don't have too many options. The big bore kits they used to sell are no long available from any of the distributors I've contacted. Oh well, I'm just having fun tinkering.
You would be hard pressed to notice any actual measurable difference from that 7cc you wish the engine had.

Like I said, if you really want to go on a quest for power, you could get into actual engine tech and go crazy to get quite an impressive level of power for these little engines. The OHC motors have the advantage of being able to fit camshafts more readily than the OHV CG motor, which would require a cuistom cam grind or sourcing a performance cam from another part of the world.
__________________
Hawk Information and Resource guide: http://www.chinariders.net/showthread.php?t=20331
2018 Hawk 250 - Full Mod list here. http://www.chinariders.net/showpost....62&postcount=1
2024 Royal Enfield Shotgun 650
https://chinariders.net/showthread.php?t=34124


 
Reply With Quote
Old 10-26-2018, 03:14 PM   #7
JerryHawk250   JerryHawk250 is offline
Moderator
 
JerryHawk250's Avatar
 
Join Date: Oct 2016
Location: Houma, La.
Posts: 11,713
Quote:
Originally Posted by Megadan View Post
You would be hard pressed to notice any actual measurable difference from that 7cc you wish the engine had.

Like I said, if you really want to go on a quest for power, you could get into actual engine tech and go crazy to get quite an impressive level of power for these little engines. The OHC motors have the advantage of being able to fit camshafts more readily than the OHV CG motor, which would require a cuistom cam grind or sourcing a performance cam from another part of the world.
I wonder if a Hot Cam we used on the Honda 200x for racing would work on these CB engines? You can still find them used on Ebay.
BTW Dan, Glad to see you been able to visit more often.
__________________
2024 Linhai 300 ATV 4x4
2023 Lifan Lycan 250 Chopper
2023 Venom Evader
2022 Lifan KPX250
2020 Kawasaki Vulcan S (Sold)
2004 Honda ST 1300
2016 Black Hawk 250 (sold)
Keihin PE30 carb,125 main,38 slow.Pod filter,ported & decked head 10:1 CR,Direct Ignition Coil,15/40Sprockets,NGK DPR8EIX-9,De-Cat,Dual Oil Cooler,Digital Cluster
2016 Cazador180 XL
2014 Coolster150
JerryHawk250.com
My YouTube Channel


 
Reply With Quote
Old 10-27-2018, 10:39 AM   #8
crackerjac   crackerjac is offline
 
Join Date: Sep 2016
Posts: 104
Well I found a source for the 70mm pistons for dirt cheap. Would it be worth the extra cost to machine the cylinder? Overheating issues? Probably not not worth it unless you have access to a machine shop and want to play. These motors are a dime a dozen but machining costs do add up. Cam grinds could be played with.



Quiet a bit could be taken off the head to up compression and the valves would still not be close to the piston.


Anyway, just playing a thinking out loud.


 
Reply With Quote
Old 10-25-2018, 12:43 PM   #9
Megadan   Megadan is offline
 
Megadan's Avatar
 
Join Date: Apr 2017
Location: Omaha, NE
Posts: 8,110
Quote:
Originally Posted by crackerjac View Post
Question, what's the best mods to make with these 167FMM motors?
A ported and shaved head, larger carb (A true 30mm smooth bore), and a good free flowing exhaust will give the most bang for the buck on most of these motors. Instead shaving the head, if you want to get into more advanced motor building you could deck the cylinder to get the quench down to a .035 range for the "best" high compression build, but to achieve this you have to take quite a bit from the top of the jug, which can then result in having a REALLY high compression ratio, so a dished piston would be needed to bring it back down to a reasonable level.

You won't really find a "big bore" kit for these motors anymore as most companies found the gains to be minimal and the cylinder started having trouble with cooling. This is why CCW stopped carrying their big bore kits. In their own words, the gains were minimal and not worth the cost. Spending hundreds of dollars to gain 19cc and no real discernible difference in power or torque. Considering those guys managed to squeeze 23 wheel HP out of a CG250, I will take their word on it.
__________________
Hawk Information and Resource guide: http://www.chinariders.net/showthread.php?t=20331
2018 Hawk 250 - Full Mod list here. http://www.chinariders.net/showpost....62&postcount=1
2024 Royal Enfield Shotgun 650
https://chinariders.net/showthread.php?t=34124


 
Reply With Quote
Old 07-02-2021, 10:03 AM   #10
Marvin610   Marvin610 is offline
 
Join Date: Jul 2021
Posts: 3
Is this thread still active? I've got a lifan 167fmm that I swapped on to my Honda z50 monkey. I've done a lot of research and mods to my engine. So I have found that it's a 230cc(not a 250) and makes absolutely no power stock. The reason for this is cooling issues, stock the engine oil temp gets up to 250°F


 
Reply With Quote
Old 07-02-2021, 12:50 PM   #11
alex_in_az   alex_in_az is offline
 
Join Date: Aug 2013
Location: Goodyear, Arizona
Posts: 412
Quote:
Originally Posted by Marvin610 View Post
Is this thread still active? I've got a lifan 167fmm that I swapped on to my Honda z50 monkey. I've done a lot of research and mods to my engine. So I have found that it's a 230cc(not a 250) and makes absolutely no power stock. The reason for this is cooling issues, stock the engine oil temp gets up to 250°F
you lose a bit of power when it's hot, but not that much. I can still get up to 70mph in summer here in AZ when its 110+f
__________________
2020 Tao TBR7
9.3:1 PnP head
CRF230F exhaust
4 degree advance key
290 degree cam
Nibbi PE30 and cone filter

Front fork brace


 
Reply With Quote
Old 07-22-2021, 10:39 AM   #12
Marvin610   Marvin610 is offline
 
Join Date: Jul 2021
Posts: 3
I thought I wrote a lot longer letter, but what I meant was that I figured out there's a lot of potential for the lifan. The engine stock has an overheating problem, which can result in the piston heat seizing in the cylinder. I've installed an oil cooler with an electric oil pump. Oil temps went from about 250°f down to 150-180°f.


 
Reply With Quote
Old 02-15-2023, 06:28 PM   #13
Thumper   Thumper is offline
 
Thumper's Avatar
 
Join Date: Feb 2021
Location: Kansas City
Posts: 2,733
displacement

Everywhere I have looked, I hear 65mm stroke for this engine. So if the cylinder is 67mm:

Use the Spicer engine displacement calculator or equivalent to determine true displacement:

https://spicerparts.com/calculators/...ent-calculator
67mm bore x 65mm stroke = 229.17
__________________
No matter where you go, there you are


 
Reply With Quote
Old 02-15-2023, 06:45 PM   #14
Megadan   Megadan is offline
 
Megadan's Avatar
 
Join Date: Apr 2017
Location: Omaha, NE
Posts: 8,110
Quote:
Originally Posted by Thumper View Post
Everywhere I have looked, I hear 65mm stroke for this engine. So if the cylinder is 67mm:

Use the Spicer engine displacement calculator or equivalent to determine true displacement:

https://spicerparts.com/calculators/...ent-calculator
67mm bore x 65mm stroke = 229.17
Yes. That is known to most of us. A 70mm bore makes it as close to a true 250 as you get. It's just like the 200cc GY6 scooter engines are 168cc. Just marketing bullhooey
__________________
Hawk Information and Resource guide: http://www.chinariders.net/showthread.php?t=20331
2018 Hawk 250 - Full Mod list here. http://www.chinariders.net/showpost....62&postcount=1
2024 Royal Enfield Shotgun 650
https://chinariders.net/showthread.php?t=34124


 
Reply With Quote
Old 07-22-2021, 11:01 AM   #15
Mudflap   Mudflap is offline
 
Join Date: Sep 2014
Posts: 1,929
It's good to have oil temps over 212° f so any moisture boils off.


 
Reply With Quote
Reply



Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 05:23 PM.


Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.