Smallest 50cc 4-stroke engine

[Pezz]

G'day All,

I am building up a small engine hybrid pushbike and have been looking at the various cheap engines on ebay.

Plenty of 2 stroke 50cc available but, I want something a little quieter.

I am looking for what 4-stroke engine is the smallest dimensionally.

I would like to option to increase the displacement at a later date.

I had a 140cc Lifan but it was a little too big and heavy for what I am working on.

Any suggestions or should I just look at 2 strokes?

Pezz

 

[MiniFighter]

Just go with the 2 stroke mate, weight and physical size wise a 50cc isnt a great deal smaller than the 140 you got/had.

 

[darkrider]

if you had the cash then i would go for a crf50 engine but if not just find a place that will sell you a lifan 50cc also the 110's will have a bit of a kick and are semiauto but for a 4stroke ur looking at paying a couple of hundreds for a new one

u could always just keep a eye out for 2nd hand ones i cant remember seeing any recently but thats probally ur best bet

 

[Barnesd09]

get one of there little enigines will push 14hp out of it. Be sweet on a pushy and could get you up near 100km/h.

But stick with a 2 stroke, light easy and cheap. They can be quietened down by having the correct pipe and muffler put on.

 

[motodevo]

just grab a lifan and build something like this, Scorpa 4tricks

 

[09crf_149]

get one of there little enigines will push 14hp out of it. Be sweet on a pushy and could get you up near 100km/h.

But stick with a 2 stroke, light easy and cheap. They can be quietened down by having the correct pipe and muffler put on.

yeahh mate just grab one of those there on special aswell only $2,320

 

[FMX_22]

get one of there little enigines will push 14hp out of it. Be sweet on a pushy and could get you up near 100km/h.

But stick with a 2 stroke, light easy and cheap. They can be quietened down by having the correct pipe and muffler put on.

I think he said cheep lol

 

[Pezz]

Thanks for the replies :thumbup:

I can see the merit of the simple 2 storke option asnd keeping it all light.

I really like the FX Bikes effort too

This is my current build, for this Scrapheap Adventure Ride

Its a 1975 CB400/4 converted into an XR460 Four

 

[rumble]

The other option is looking at whipper snipper motors ect. Ive got a Stihl extension chain saw thats 4-stroke, not sure what cc it is.

Zenoha are generally the 2strokes used on bikes.

 

[The_GDFP]

Darn shame they're so expensive, but some of the 50cc-ish model airplane engines are neat as.

 

[The_GDFP]

Cheap dinger?
Motor bike gas kit *WE SHIP TO CA!* 80cc bicycle engine - eBay (item 270724252325 end time Apr-21-11 10:38:25 PDT)


4-stroke
http://cgi.ebay.com/4-stroke-Motori...Cycling_Parts_Accessories&hash=item1e5a048795

 

[Pezz]

I wonder if one could remove the gearbox and unnecessary housings off the back of the postie type engines and run a small sump and a small CVT for drive?

Would have to take some weight off ??

 

[The_GDFP]

I wonder if one could remove the gearbox and unnecessary housings off the back of the postie type engines and run a small sump and a small CVT for drive?

Would have to take some weight off ??

Not likely to save much mass. Honda has done some thing along those lines, recently, to the standard engine. Some of the scooter-based CVT's are light as well.

 

[motodevo]

could get an engine out of an old nc50 scooter, 2 stroke 50cc and weigh next to nothing, or just buy an nc50, pretty much a motorised bicycle anyway. You can get em real cheap,bought one for $70 a few years agoBikePics - 1980 Honda NC 50 (Express)