Paging TOG (or anyone else into Honda based four stroke single lumps)

The Sach Madass, formerly of one Rope of this parish has a 125 'X-Sport'
lump in it - I believe they're a Honda copy.

Bearing in mind the offspring of said parishoner managed to blow up at least
two of the 50cc versions, would tuning this be a 'bad thing', and if not,
any idea as to what can be had out of them in terms of BHP / top end?

I've found a place that specialises in these locally that just happen to
have most of the bits to fix the bike up at sensible prices, (including a
set of forks which looked like it was going to be an expensive PITA), so I'm
happy to throw some time at it.

ObPugMoped: I might streetfighter this - the boy hasn't turned his nose up
at the idea, and it'll be a lot less hassle.

--
JackH

98 Honda VFR800FiW
05 Sachs Madass
03 VW Passat TDI Sport
89 Vauxhall Nova 1.3 Pearl

 

If it's a Honda copy, why not source a Honda engine? For a start, tuning
it would be a safer bet, and for another thing, parts will be easier to
source.

I know for a fact that the old SOHC Honda 125 engine could be taken out
to 180cc: 150cc big bore kits crop up from time to time.

There are three main versions of the OHC Honda 125. There's the original
basic version, put in the CB125S, SL125, XL125 etc. Five-speed, about
10-11bhp, rev counter redlined at 9500, top whack at the redline about
65mph.

They tweaked the engine for the CB125J (also, confusingly, called the
CB125S and badged as such on the side panels). The redline on that went
up to 10,000rpm. Bigger valves. Maybe a slightly different cam. Anyway,
that was good for 70mph. Claimed BHP was 14.

Then there was the final version: the CB125RS (which I've just bought).
I don't know what (if anything) they did to the engine, because it was
even peppier than the J and was redlined at 10,500rpm. Of course, the
12bhp limit was in force by then, and they declared it only made 12bhp,
but the one I tested would hit 75mph, so I suspect Honda measured its
power at the back wheel instead of the crank, or the filler cap, or
wherever.

The RS had a completely different carb: a whizzy thing with an
accelerator pump, so it's probable this is where the extra poke came
from.

Anyway, if I wanted the extra whizz, it would have to be the RS, but the
engine's useless without the pokier carb (Dave Silver still lists the
carb brand new for £69+VAT). Or you could experiment with whatever other
carb comes along.

The alternative is to source an engine from the XL185 dirt bike and drop
that in: I *think* it's just a hogged out 125 lump. Certainly, it looks
identical. Very rare, though, and it'll be hard to find a good'un.

 

The engine in the Sachs Madass is a development of the C90 engine, not
the upright 125s

--
Lozzo
SV650S K5, CBR600F-W, SR250 SpazzTrakka, SR250 Project SpazzCaffer
Ford Maverick 2.7 litre 4x4 Turbonutterbastard with VTOL.
and a shit load more 2-wheeled junk in the garage
I believe in free speech, but I still have to pay my phone bill

 

Is it? Oh, OK, you're quite right, then.

 

So I've just been informed.

 

Silly question, but does it have a manual clutch or is it like a Cub in that
respect as well?

I've done little with it bar park it up since I got it back.

--
JackH

98 Honda VFR800FiW
05 Sachs Madass
03 VW Passat TDI Sport
89 Vauxhall Nova 1.3 Pearl

 

AAAARRRGGGHHH!!!!!

 

Like I said, he has to get a job to pay for the running costs before he can
have it on the road, so given he's done nothing about that as of yet, I'm
doing little about the Pug bar accrue all the parts needed to get it up and
running.

Speaking of which, don't suppose you've found the other side pod for the
fairing yet have you?

And... don't suppose you know the whereabouts of the Madass battery cover /
airbox?

TIA

--
JackH

98 Honda VFR800FiW
05 Sachs Madass
03 VW Passat TDI Sport
89 Vauxhall Nova 1.3 Pearl

 

Should be a hoot to ride round town once finished, and means I can hopefully
leave the VFR parked up once the roads get salty.

--
JackH

98 Honda VFR800FiW
05 Sachs Madass
03 VW Passat TDI Sport
89 Vauxhall Nova 1.3 Pearl

 

Ta muchly.

--
JackH

98 Honda VFR800FiW
05 Sachs Madass
03 VW Passat TDI Sport
89 Vauxhall Nova 1.3 Pearl