Planet Minis

SJ90 · 03-06-2009, 09:22 AM

Hi, I'm looking to rebuild my 1979 ct70 and I'm not sure what to do. I'm looking to get more power out of it while I'm working on it and i was wondering what my best options are.

I've looked at the yx160 engines and I've heard some people on here claiming they're not the most reliable engines. I've also looked at the Lifan 150s which seems to have a better reputation. In some of the older threads people were have problems with shifting I think I was wondering if this has been fixed. I've also considered building a tbparts motor to 110cc but I also read that the ct70 3 speed isn't really strong so I'm concerned about that.

If you have any experience with any of these or other machines like it please let me know how it turned out, good or bad.

I ride this bike as my toy around in the woods so it won't be having the life beat out of it every weekend but i plan on riding it hard here and there.

What I'm looking for out of this bike is something I can trust to not blow up after a week but still stay around the 600-700 dollar mark. I know that’s low but I'm not trying to build a race bike just add some good power to the little bike.

Thanks for any help you guys can give me.

dirtslammer · 03-06-2009, 10:07 AM

check the vendor section. g2moto is selling evos 140cc engines for 319.00. its a good engine and pretty fast.

firepower354 · 03-06-2009, 10:42 AM

The tried & true 125GPX is a good choice and plenty powerful. The 140 mentioned is too, if you need the extra oats.

cdoublejj · 03-06-2009, 10:43 AM

thats a pretty good deal they are all pretty good and i think the issues with early chinas have been fixed for the most part.

SJ90 · 03-06-2009, 05:57 PM

hey thanks for the link. As long as that motor holds up i'm sure i'll be extremely happy with it. Since the motor doesn't come with a carb I was wondering what you thought was the best way to go. he said he has a OKO model and several mikuni models.

One last question i read that lifans are more reliable motors and the yx engines but yx is a faster motor. Is this true? Does anyone own one of these thats been hidden for a while?

Blackwoodz · 03-06-2009, 06:22 PM

I have a Jailing 125 or a Lifan 138 complete for $275 shipped.........both are basically new with just a few hours at most.
Complete setup and come with a billet oil cooler. Pictures are in my albums on the girls bikes album.

SJ90 · 03-06-2009, 06:58 PM

sorry Blackwoodz my last post might have been confusing i was looking for someone with time on a evos 140cc to tell how it holds up over time. I'm looking for a new motor but thanks anyways.

AHPminis · 03-06-2009, 07:04 PM

Quote:

Originally Posted by SJ90

hey thanks for the link. As long as that motor holds up i'm sure i'll be extremely happy with it. Since the motor doesn't come with a carb I was wondering what you thought was the best way to go. he said he has a OKO model and several mikuni models.

One last question i read that lifans are more reliable motors and the yx engines but yx is a faster motor. Is this true? Does anyone own one of these thats been hidden for a while?

One thing you should know about the Lifan 150 is that none of the importers bringing the engines into the states are bringing in spare parts. I have spoke to numerous guys who were frustrated to find they could not even source a spare piston for their engine.

The YX 140 motors are a good bet, they have a strong 4 up transmission, 5 plate clutch and also a big valve head. We sell a model of it that comes with a 26mm carb setup as well.

The 140 would be plenty for what your doing, produces great tq and they are the same price as the 125 motors mentioned earlier but come with that larger head which allows them to pull stronger/longer but still retain a lower compression in stock trim (just as all chinese motors do) which aids in reliability that your looking for. Hope this helps, if you have any questions about more motor comparisons you can PM me.

SJ90 · 03-09-2009, 05:39 PM

Hey i still am not sure with what to do with my bike. I like the reports of the lifan 150 but it concerns me about not being able to get parts. Does anyone know where to get some.

Also i have a xl70 motor with a 4 speed manual clutch and a ct70 motor with a 3 speed and the auto clutch. Does anyone on here have experience building a bore and stroked motor on these motors? Is either one a stronger base?

This is the list of parts from dratv i have come up with.

88cc hyper kit
52mm crank
high output oil pump and oil cooler
A heave duty clutch(not sure which one yet)

Will this be more reliable then a gpx or lifan?

cdoublejj · 03-09-2009, 05:43 PM

the 88 is obviously smaller yes it would be more reliable but, unless you are absolutely punishing your engine on purpose they are both just as good but, the 88 is much more expensive.

SJ90 · 03-09-2009, 06:47 PM

would the stroker crank make to much power for the bottom end of the ct motor? I think it bumps it up to 110cc.

cdoublejj · 03-09-2009, 06:53 PM

i haven't messed with that stuff but know lifan that i have in my Z pumps out power i run 14/26 on it

03-06-2009, 09:22 AM	#1 (permalink)
SJ90 PM Newbie Join Date: Mar 2009 Location: Vancouver Posts: 49	Which Motor for a Trail Bike Hi, I'm looking to rebuild my 1979 ct70 and I'm not sure what to do. I'm looking to get more power out of it while I'm working on it and i was wondering what my best options are. I've looked at the yx160 engines and I've heard some people on here claiming they're not the most reliable engines. I've also looked at the Lifan 150s which seems to have a better reputation. In some of the older threads people were have problems with shifting I think I was wondering if this has been fixed. I've also considered building a tbparts motor to 110cc but I also read that the ct70 3 speed isn't really strong so I'm concerned about that. If you have any experience with any of these or other machines like it please let me know how it turned out, good or bad. I ride this bike as my toy around in the woods so it won't be having the life beat out of it every weekend but i plan on riding it hard here and there. What I'm looking for out of this bike is something I can trust to not blow up after a week but still stay around the 600-700 dollar mark. I know that’s low but I'm not trying to build a race bike just add some good power to the little bike. Thanks for any help you guys can give me.

03-06-2009, 10:07 AM	#2 (permalink)
dirtslammer PM Newbie Join Date: Sep 2007 Posts: 76	Re: Which Motor for a Trail Bike check the vendor section. g2moto is selling evos 140cc engines for 319.00. its a good engine and pretty fast.

03-06-2009, 10:42 AM	#3 (permalink)
firepower354 Advertiser Join Date: Oct 2006 Location: Flint MI Posts: 10,989 My Mood:	Re: Which Motor for a Trail Bike The tried & true 125GPX is a good choice and plenty powerful. The 140 mentioned is too, if you need the extra oats. __________________ If it has my name on it I did it;) FirepowerMinis.com Custom FPM parts and engines. Parts and service for all makes. Honda Trail Bikes parts and accessories. Pitster/Piranha/Thumpstar bikes, parts, engines and accessories.

03-06-2009, 10:43 AM	#4 (permalink)
cdoublejj 3rd Gear Member Join Date: Oct 2008 Location: St.Joe MO Posts: 1,367 My Mood:	Re: Which Motor for a Trail Bike thats a pretty good deal they are all pretty good and i think the issues with early chinas have been fixed for the most part.

03-06-2009, 05:57 PM	#5 (permalink)
SJ90 PM Newbie Join Date: Mar 2009 Location: Vancouver Posts: 49	Re: Which Motor for a Trail Bike hey thanks for the link. As long as that motor holds up i'm sure i'll be extremely happy with it. Since the motor doesn't come with a carb I was wondering what you thought was the best way to go. he said he has a OKO model and several mikuni models. One last question i read that lifans are more reliable motors and the yx engines but yx is a faster motor. Is this true? Does anyone own one of these thats been hidden for a while?

03-06-2009, 06:22 PM	#6 (permalink)
Blackwoodz 3rd Gear Member Join Date: Aug 2008 Location: SC Michigan Posts: 3,619	Re: Which Motor for a Trail Bike I have a Jailing 125 or a Lifan 138 complete for $275 shipped.........both are basically new with just a few hours at most. Complete setup and come with a billet oil cooler. Pictures are in my albums on the girls bikes album.

03-06-2009, 06:58 PM	#7 (permalink)
SJ90 PM Newbie Join Date: Mar 2009 Location: Vancouver Posts: 49	Re: Which Motor for a Trail Bike sorry Blackwoodz my last post might have been confusing i was looking for someone with time on a evos 140cc to tell how it holds up over time. I'm looking for a new motor but thanks anyways.

03-09-2009, 05:39 PM	#9 (permalink)
SJ90 PM Newbie Join Date: Mar 2009 Location: Vancouver Posts: 49	Re: Which Motor for a Trail Bike Hey i still am not sure with what to do with my bike. I like the reports of the lifan 150 but it concerns me about not being able to get parts. Does anyone know where to get some. Also i have a xl70 motor with a 4 speed manual clutch and a ct70 motor with a 3 speed and the auto clutch. Does anyone on here have experience building a bore and stroked motor on these motors? Is either one a stronger base? This is the list of parts from dratv i have come up with. 88cc hyper kit 52mm crank high output oil pump and oil cooler A heave duty clutch(not sure which one yet) Will this be more reliable then a gpx or lifan?

03-09-2009, 05:43 PM	#10 (permalink)
cdoublejj 3rd Gear Member Join Date: Oct 2008 Location: St.Joe MO Posts: 1,367 My Mood:	Re: Which Motor for a Trail Bike the 88 is obviously smaller yes it would be more reliable but, unless you are absolutely punishing your engine on purpose they are both just as good but, the 88 is much more expensive.

03-09-2009, 06:47 PM	#11 (permalink)
SJ90 PM Newbie Join Date: Mar 2009 Location: Vancouver Posts: 49	Re: Which Motor for a Trail Bike would the stroker crank make to much power for the bottom end of the ct motor? I think it bumps it up to 110cc.

03-09-2009, 06:53 PM	#12 (permalink)
cdoublejj 3rd Gear Member Join Date: Oct 2008 Location: St.Joe MO Posts: 1,367 My Mood:	Re: Which Motor for a Trail Bike i haven't messed with that stuff but know lifan that i have in my Z pumps out power i run 14/26 on it

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