lifan transplant into postie bike ct110

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deekay

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I have started my jorney transplanting a 125cc Lifan with a 4 speed clutch type gearbox into my 1998 postie. I have started with a good bike in very sound condition that was abandoned due to clutch failure. I researched the cost of repairs given the damage done and the best way out was a new Chonda engine/gearbox assembly. I will try to document my version of "how to" and tell of problems etc found alond the way. I have been preparing the bike whilst waiting for the engine to arive getting everything clean, repaired and ready. Have found lots of poor workmanship that has been done to this poor little bike which I have had to undo. Motor arrived today and first job before even thinking about transplant is on trial fitting of bits. I discovered the mounting bolt holes on the Lifan are undersized, on measuring with a vernier I found Honda bolt size to be 10mm, much larger than original, have drilled out holes to 10 mm and fitted the original carby and manifold to position the carb in the right place for original aircleaner use. I loved the wiring diagram, all in Chinese, lucky colours match almost perfectly. Tommorow after work will see some further progress.
 
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sounds like it will be a good build, show us some pics of your progress if you can

some one give me a free postie bike!!!
 
Today saw the fitting of the engine, all complete and bolted up, a bit of buggering around but am very happy with the result. Postie did a conversion very similar and there is a US site with a bit of "how to" on it but I have taken a totally different approach. When you fit the motor to the top mount you can see half the bottom mount hole and it is no where near the original. The other guys solved this by making an adaptor mount but I was not happy with the design so went another way. I notched the frame so I had a hole lined up with the new bottom mount and welded a tab over this new hole. I then packed the gap between the new tab and the engine and used a longer bolt to secure it, (another spare top mount bolt which is longer). It is secure and solid and the line up of sprockets is perfect. I will try to upload some pics as soon as I work out how, The other bike in the last pic is another love of my life, a motorised chopper that I ride to work, it is so comfortable with the sprung seat and fat tires. I wont get any time to work tommorow but will keep you informed of progress, so far I am rapt.
 

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last few pics. One more thing of note, the lifan comes with a 14 tooth front sprocket and the postie has a 15 tooth so with more cc's and lower gearing this thing should accelerate hard, just what I like, deekay
 

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50cc 2 stroke in photo.

G'day mate, nice job on the old postie, good luck with it. I saw your photo of 2 stroke 50cc bicycle. Does it go well, I was thinking of building one just to get around town on. How fast, how long have you run it for? Cheers.
 
had the chopper for a couple of years, not fast as it can only put out 200watts to be legal, good cruizer not sprinter, pedal to start and sometimes pedal up hills if it slowes down, lots of fun
 
do you have a pic of the electric bike deekay i wanna see
 
oh sorry i didnt notice the links i seen it now
 
Does any one know what oil 138 lifan uses ,thanks
 
where does the green coil wire on a fifan 138 go to?
Thanks
 
She runs, second kick and vroom away we go, Some further problems, the drive sprocket on a Lifan is the wrong chain profile and one tooth too small, 14 instead of 15 so good friday will see me at work at some stage on the lathe turning out the centre of the postie sprocket as it has too small a bore, outer diameter of the shaft teeth ok but inner diam is too small, only other option would be to get a 18mm bore sprocket 15 teeth to suit the chain fitted on a postie. Second job for today was to fit a manual clutch, painless as universal lever and perch sets are readily available and I made up a universal cable, fits neatly under original cover and works sweetly. Exhaust a bit of a drama, bolts straight up but Lifan port is much deeper in the head that original. With pipe bolted up and new gasket it is not tight and is leaking, will make up a spacer or fit two gaskets, will see which is easier. No viabrations, using colour for colour on wiring everthing works, battery charges, motor runs and starts perfectly, everything spot on, so far a brilliant conversion, tommorow machining and sealing up exhaust and final tidy up stuff, almost there, will take a few more pics and post them, cheers, deekay.
 
Hey man been following ur progress looks insane. once u finish it u'll have to get video up!
I was going to do a coversion a while ago but never got around to it. i found this a while back doubt if its any help to u now tho lol. http://www.dratv.com/ct.html
hope everything goes shwell, keep us updated.

Cheers, Ben.
 
Yes saw this article before I started but did not like their approach to the bottom engine mount, too flexible which might allow viabration, I don't want that, yesterday machined out front sprocket to fit and made up a 6mm extension to lengthen the exhaust so it seated on the gasket, smick. Went to fit the chain but found the sprocket position forward on the chonda so the chain was too short, no shops open on good friday and no mates with a short length of 428 chain so today I will get a new longer chain and go for the first ride. Bash plate/frame brace was fun, nothing lined up here and this is what holds the footpegs on. Designed and made an adaptor plate out of 6mm X 25mm aluminium flat bar . Bolted the footpegs onto the bash plate using the front bolts then swung the assembly up into position so pegs cleared casing etc then marked the rear boltholes on the engine and the rear boltholes on the pegs and made a 4 hole adaptor plate. Bolted this all up and it looks and works the ducks guts. I am ready for running in and the first ride apart from the chain. Everthing is very rigid and no vibes at all. This has been a fun project, if you did not know you would not pick it from a standard postie but for the black engine and once I get it run in it will be time to wring some more horses out of it with carb and exhaust changes, a work in progress. I guess my only comment is that this is a job that requires a reasonably good workshop and some skills at using tools but apart from that realy a piece of pie. All up about 10 - 12 hours work and this was doing it first time. What would I do differently, I would weld the bottom engine mount brackets on the inside of the frame instead of the outside so I did not have to shim, apart from that I wouldn't do anything differently, den.
 
Lookin great mate, your chopper is awesome.
 
She goes, man all that work was totally worth it, no vibes smooth as, plenty of pulling power. I weigh 120 kilo's and it rockets along, plenty of acceleration, no noises and handles faultlessly. Very pleased, had to sort out a few very minor items but an unreal result. Cannot hear it at idle, for about $450 I have an as new postie bike good value. 80 kmh running in seams cool, still got plenty up my sleave and not accelerating too hard or labouring it, nothing left to tell, that seems like it unless anything comes up, will take some more picks and post them over the next few days, happy motorcycling to all, only decision is scooter (Zuma), chopper, postie, Lotus style clubman, BMW convertible or Rav 4, decisions decisions. Den.
 
She goes, man all that work was totally worth it, no vibes smooth as, plenty of pulling power. I weigh 120 kilo's and it rockets along, plenty of acceleration, no noises and handles faultlessly. Very pleased, had to sort out a few very minor items but an unreal result. Cannot hear it at idle, for about $450 I have an as new postie bike good value. 80 kmh running in seams cool, still got plenty up my sleave and not accelerating too hard or labouring it, nothing left to tell, that seems like it unless anything comes up, will take some more picks and post them over the next few days, happy motorcycling to all, only decision is scooter (Zuma), chopper, postie, Lotus style clubman, BMW convertible or Rav 4, decisions decisions. Den.
 

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