Lifan 163FML vs CG250
 

Hello chinariders, first post

I have a 1972 Honda cb100 with a lifan 163FML installed. My question is, does anyone know if the dimensions/mounting holes are the same between the 163FML and the generic cg250? As in could the current motor be easily swapped with the cg250? Any feedback would be much appreciated thanks!

Yes, they should be the same, although it's possible (I don't remember for sure) that the top mount for the cylinder head will be slightly higher.

The engine case mountings should be the same.
the head mounting at the top is probably off /slightly different.

Be aware the OHC engines have seperate valve adjustment access caps...whereas the CG engines require the rocker cover to be removed...

So the space between the frame and the rocker cover might make valve adjustment accessibility an issue.

the 200cc engines might be a better fit for Honda frames 150cc or less.

Thanks for the response franque, do you know approximately how much taller the cylinder would be on the cg250? Im worried the cylinder head might contact the frame. I would post a picture but the feature doesn’t seem to be working

Thanks XL, I would love to fit another 200cc however I can’t seem to find any here in the US at the moment. There are however a proliferation of listings popping up on eBay for cg250 motors. The listings are all titled something along the lines of “ New 200cc-250cc 4-Stroke ATV Dirt Bike Engine CG250 Manual 5-Speed Transmission”. Is it possible this means I could order a 200cc version of the cg250 and receive a cg200 in the mail?

Yes I've noticed the cg200s seem to be getting phased out of production...

The other option is to opt for the alternative OHC timing chain alternative rather than the CG OHV pushrod engine if 250cc is only available.

You will also need to be wary of counterbalanced engines that might foul on the frame. the counter balance will look like a slight bump at the front of the case.

Hard to say how it would fit in a CB100 frame all round (photo would help)...Only experience is I have is with my XL185/CG250 swap and I've hit a few snags along the way.

I've looked at some CB100s and I would think a OHC type is a better prospect...

I will try and upload pics later, haven’t had time with work. I was able to zoom in on the listing pictures and spot a “167FML” stamped in the usual spot. Would this engine likely be the same in outer dimensions as the 163? I know the L in FML stands for 200cc so I’m assuming this is the 200cc option for the listing.

1 cylinder 67mm piston/bore. Most likely a 250cc engine case.

CG pushrod OHV. CB timing chain OHC. both can be labled 167FML/FMM

a Chonda 200cc normally marked 163FML

The L indicates 200cc... Whether it actually is is another question, but it would be an "M" if 250cc "class"... I've seen them mislabel the bore diameter, but the letter is almost always the correct indicator for the displacement class.

I can confirm that my Zongshen 167FMM is a bog standard CG250. that has a 67mm piston.

If some of the manufactures are stamping 167FML its a bit interesting.

I know if you online search either 167FML/FMM you basically get the same results. Which is why I mostly go by the nominal bore size and the physical appearance..

Yes the 250s are bigger than the 200s. the lower engine mounts are the same as they are all built up from the original Honda CG125 platform. the top mount can be a bit skew-whiff

Ok, so it seems i really can't be sure of the height of the cylinder head until its in my garage.


Here are a couple pictures of the bike and a link to the ebay listing. If you zoom in on one of the pictures you can see the "167FML".


https://www.ebay.com/itm/18506490264...3ABFBM2KS2p_xf

The bike photos looks like a Cg250 engine case with a CG125/200 rocker cover.

the eBay listing looks like a CG200 case. but shows a 250cc cylinder jug...

So looks like both are possible hodgepodge assemblies. The fact there is no manufacturer mark on the serial number is also a sign that it could have been assembled anywhere from any unknown parts bin quality.

Also I don't believe that top engine mount DIY bracket is actually doing much