Dreaming of a Lifan 140cc in the postie - tech comments?

Very off topic and very early days (so nothing exciting yet ) but I'm doing a bit of research into replacing the 105cc engine in the postie (ct110, '99 model) with a Lifan 140cc (https://www.elstars.com.au/products/lif ... 9e58bb760b)

I've read mixed reports on the web about how easy the replacement is. Some seem to report a simple bolt in, others talk of welding on new mounts due to slightly off engine bolt positions, others of just using brackets or bushels.
So I can't find anything definitive.
I've found a yahoo group (http://autos.groups.yahoo.com/group/hon ... d=69370327) that might help, but it has no guest access and I'm hesitant to join until I'm closer to doing something.

If I do do it I'd be more than willing to experiment and learn (eg I have no welding experience), but I'd prefer not to go into it blind, and the less time off the road the better.

So I figured I'd just send some feelers out in here to you mechanical gurus and see what thoughts or advice you guys have - particularly if you've heard or know of anything definitive about how to do it.

And to keep it on topic the postie might finally go green if/when I do it
TIA
ty

It would be interesting to see it in action...

Max power 10KW @ 7500RPM. Why bother? I would think you would be better off putting the money towards another bike.

you may not want this, but I am gong through our old farm crap and there is some ct90 stuff, most has gone but I remember a cush drive, a few boxes, barrels etc, hey I dont know but hell, it could be good. It will be dumped soon, probably already has

but go the CT oonhonda ffs

Just put the 125cc big bore kit on the beast, then jet it up and you will get a better result.

@Hoffy: It would
@Nelso: cos current HP is 7.5@7500 and a new bike isn't an option
@Jonno: I'm not sure any of the ct90 stuff will fit, but I could be wrong. Maybe let me know what you have and we'll see.
@JetPilot: really? I'd heard that the Lifan was the better upgrade and that the big bore didn't actually give much in the way of HP. I'm more than willing to be convinced though.
ty

6. How can I make my Postie Bike go FASTER?

This is the question I am, without a doubt, asked the most. There are many ways to increase power of your postie bike. Below are some that I know of: (Warning: Most of these mods will make your bike illegal for on road use).

i. Reduce weight - remove everything that is not needed e.g. rear rack, crash bars, lights, battery etc. Note: The rear carry rack incorporates an airflow restrictor which will cause the engine to run too lean if removed. In order to get around this you need to install some other form of air flow restriction in the air intake hose or employ option ii. below.
ii. Modify the exhaust (by removing the baffles) and air intake (remove the rear carry rack) and
increase main carby jet size to approx 0.85mm.
iii. Change front/rear chain sprockets to alter gear ratios. e.g. Reducing the front sprocket by 1 tooth to a 14 tooth will increase acceleration but reduce top speed.
iv. Re-tune engine to run on Methanol (A Racing Fuel) Involves increasing
main jet to about 1.5 mm and changing engine oil. (a significant increase in power is achieved)
v. Increase compression ratio (requires cylinder head to be machined)
vi. Install a modified racing cam (available from Tighe CAMS in Queensland)
vii. Install a 125cc big bore kit - these are rare but turn up on e-bay from time to time.
viii. Have your engine professionally modified and dyno-tuned. (eg lightened
flywheel, lightened crank shaft and incorporation of mods listed above)

http://www.postiebikes.com/faq.htm

Go for it mate, riding a postie bike is not everyone's cup of tea but when it's the only option then it's better than not riding at all...

Mick

Last edited by Ratmick on Sun Apr 12, 2009 4:43 pm, edited 1 time in total.

yeah I saw that site Mick - some of those options aren't realistic as they make in unroadworthy (I think), though some are a point form of JetPilot's suggestion, so I may go with them.
Thanks
ty

Go on, who would know:

vi. Install a modified racing cam (available from Tighe CAMS in Queensland)

Mick

lol I've actually been meaning to find out how much they are.
They're the type of thing that sounds expensive, but may not be for the postie.
ty

I can't imagine they'd be very...umm, big.

Not like they going to have to handle an overwhelming amount of horsepower

Mick

Or you could do it properly and just do this.

btw frank, want me to pm you all the nos postie pics i took?

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Damn Mike! you ruined the surprise!
I was going to put the NOS bottle somewhere else though - that's WAY too much of a give away

ty

There is a postie bike group or club, surely they would have the answer, sus out the white pages bound to be listed as they've been around forever.