LIFAN 100cc 2 stroke on the way. Fred (CR machine)pk 80 race engine for sale

mark20

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Sep 26, 2018
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This is heavier in weight because is has a 4 gear manual transmission along with a wet friction clutch ( regular dirtbike clutch) I found videos of people doing around 120km per hour that's around 75mph and that's with no porting or anything stock. This is a motor for a full size dirtbike or motorcycle here is a pic of the bike it comes on overseas.
i guess we will have race after i get my 97cc engine finished ;)
cant wait for the build!
 


LewieBike

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May 21, 2014
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That engine is a Lifan licensed to build Suzuki 100, without the oil injection pump and 4 speed instead of 5. They're used in agricultural bikes in Mongolia, pretty tough and simple to work on. I'm going to take a WAG that 25:1 is a bit rich for this and will probably be OK with 33:1. Similar in size power and weight to the old Hodaka Ace 90 and in a regular sized, vintage twin shock tiddler dual sport, it would make about 50 MPH all wrung out. 6.6:1 compression ratio is a little on the light side for compression, the HT engines are 6:1. Bigger ports, heavier castings, better gears, kick-starting and a 12 volt electrical system for lights. Don't expect much over 50 mpg.
 

JerboaJohn

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50mph? it's highly dependent on gearing, mix ratio, pipe etc,, 60+ entirely possible if the bike and you can take it haha. my 79 yz125 on the street did 50 and I think I had 13/52T sprockets
 

FNTPuck

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Awesome build! My next 2stroke will likely be a dirt bike motor since I really want a transmission.

Yeah, just my own point of view from years as a well-fed dude beating on bicycle components. The ultimate in "big block" to me has always been the Briggs bikes, and most of the ones I have seen are really well-built and therefore heavy, over 110lb bikes. Heck, I feel like my own white bike is a pig because it weighs 70lbs! It's all cork-stuffed steel and heavy duty slime-filled wheels. My 81" long basket bike weighs much less than that.

Anyway, this is dang good science, and science is good times if no one dies.
Correct, my Briggs is shaping up to end up at roughly 95lbs if I had to guess :(. 54" wheelbase, steel frame, moped wheels, etc. Motor is around 45lbs IIRC with NO transmission, and the bike was already on the heavy side at 33lbs stock.

Weight is better than weak! Lots of heavy parts and steel gussets to make it live. Eventually I'll make a thread here...a ton of work.
 

LewieBike

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50mph? it's highly dependent on gearing, mix ratio, pipe etc,, 60+ entirely possible if the bike and you can take it haha. my 79 yz125 on the street did 50 and I think I had 13/52T sprockets
I owned a Hodaka Ace 90 and it was out of breath at 50.

A modern YZ125 is more twice the H.P of this engine which is probably no more than 7 hp, it's not a racing bike engine. It's a transportation bike engine with wide powerband, no reed box or windowed piston. I also owned the 1977 Hodaka Road Toad 100 which had better porting, higher compression and a reedbox, about 11 H.P. tops and would just squeak out 60 mph.

So no, in a normal weight and geared motorbike this is not a fast engine.
 

JerboaJohn

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it'll have more power than the average 66cc and they are not exactly slow. add in 4spd and it'll be peppy to accelerate. ok throw out reference to old db,, Lifan states it's 8.4hp @7500, throw that out and say it's realistically 5hp to show abt same output per cc as a pk80. still looks like itd rip
 
Joined
Feb 15, 2019
Messages
57
That engine is a Lifan licensed to build Suzuki 100, without the oil injection pump and 4 speed instead of 5. They're used in agricultural bikes in Mongolia, pretty tough and simple to work on. I'm going to take a WAG that 25:1 is a bit rich for this and will probably be OK with 33:1. Similar in size power and weight to the old Hodaka Ace 90 and in a regular sized, vintage twin shock tiddler dual sport, it would make about 50 MPH all wrung out. 6.6:1 compression ratio is a little on the light side for compression, the HT engines are 6:1. Bigger ports, heavier castings, better gears, kick-starting and a 12 volt electrical system for lights. Don't expect much over 50 mpg.
This engine has the oil enrichment pump but i am not using it or the stock carb I'm running my 21mm oko first at 32 to one mix then 40:1. Common to do according to the research I've done. Everything I read from different sites say that's the first thing everyone does is eliminate that pump I'm posting an update thread because I'm building it this weekend here is a sneak peek.
 

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Feb 15, 2019
Messages
57
That engine is a Lifan licensed to build Suzuki 100, without the oil injection pump and 4 speed instead of 5. They're used in agricultural bikes in Mongolia, pretty tough and simple to work on. I'm going to take a WAG that 25:1 is a bit rich for this and will probably be OK with 33:1. Similar in size power and weight to the old Hodaka Ace 90 and in a regular sized, vintage twin shock tiddler dual sport, it would make about 50 MPH all wrung out. 6.6:1 compression ratio is a little on the light side for compression, the HT engines are 6:1. Bigger ports, heavier castings, better gears, kick-starting and a 12 volt electrical system for lights. Don't expect much over 50 mpg.
I've done my research, I know everything there is to know about this motor. I'm not worried about had mileage lol I'm going to raise the exhaust port and clean up the intake and have a performance CDI and coil. Here is a sneak peak.
 

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Feb 15, 2019
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I owned a Hodaka Ace 90 and it was out of breath at 50.

A modern YZ125 is more twice the H.P of this engine which is probably no more than 7 hp, it's not a racing bike engine. It's a transportation bike engine with wide powerband, no reed box or windowed piston. I also owned the 1977 Hodaka Road Toad 100 which had better porting, higher compression and a reedbox, about 11 H.P. tops and would just squeak out 60 mph.

So no, in a normal weight and geared motorbike this is not a fast engine.
Obviously you haven't done your research lol this has a case reed and I made the piston windowed and I've cleaned up the intake port and raised the exhaust port by about 6 degrees also have a performance CDI and coil and a professionally built expansion chamber and top speed on this motor stock is around 70 mph. So..... you tube susuki ax100 it's the same motor lol here is a pic of the case reed this is the motor just set in my bike it's going together this weekend I'm posting an update thread for it. Followed by speed viseos.
 

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