a few Monkey Bike questions :)

Hello
I just bought a ST70 Monkey Bike for £500 but it won't start. See full
details at ebay item #8075591299

Described as:
"1977 restored 05/6 honda st70 monkey bike new shocks new tyres new
seat new wiring loom . new mud guards.. chally handlebar conversion old
fold down bars included 6k on the clock works perfect just needs
battery charge selling as no storage in a mates kitchen alas.. 3months
mot left. v5 present. good condition"

I've tried bumping it down the road and it DID crank up for about 5
seconds several times. Also managed to start it from the kickstart for
about 5 seconds but then it died out again.

QUESTIONS:
1. Do I need to mix oil in with the unleaded?
2. Does it matter that the battery is flat? Does that affect the engine
starting?
3. There is key with an ignition of some kind. What's that all about?
4. hmmm, not sure what else to ask.

any general tips to revive a bike that won't start?
thanks
mark

 

I've tried bumping it down the road and it DID crank up for about 5

As it has an auto clutch and semi auto box, bumping probably wont work...

No. It's a 4 stroke

Yes. get a fully charged 12v battery off anything and wire that in, then try
to start the bike...

No idea what you mean. Ignition key is needed to complete the ignition
circuit.

Pop a new plug in.

Check it has fresh, new fuel.

Check there's a spark using the new plug and kicking over with the plug out,
but connected and touching and earthing surface, eg the cylinder head

Dave

 

WavyDavy said...

ST70s are 6 volt.

 

Hello
I just bought a ST70 Monkey Bike for £500 but it won't start. See full
details at ebay item #8075591299

Described as:
"1977 restored 05/6 honda st70 monkey bike new shocks new tyres new
seat new wiring loom . new mud guards.. chally handlebar conversion old
fold down bars included 6k on the clock works perfect just needs
battery charge selling as no storage in a mates kitchen alas.. 3months
mot left. v5 present. good condition"

I've tried bumping it down the road and it DID crank up for about 5
seconds several times. Also managed to start it from the kickstart for
about 5 seconds but then it died out again.

One I rode in Greece would flood very easily- it wasn't mine so I never
checked the float level, go for the non-owner method to start with. If you
had the choke on and started it - then left the choke on - it will be
flooded. Turn off the fuel, remove the plug. Kick it a few times - possibly
with the throttle open. Put in a new plug and kick it - it may well start.
Wait a few seconds and turn on the fuel.

It that works you may have to sort the float level - or just turn off the
fuel when you stop and turn it on again after you have started the bike.

John

 

It seemed to kind of work. I mean I was able to knock it into 1st very
easily and it then tried to start (it did start a couple of times when
bumping but cut out again)

Cool
My neighbour thought it was 2-stroke.

OK, will do that tomorrow. It's actually 6v but yeah I'll sort that out
tomorrow and try again.

Right. So it doesn't have a starter motor then? I have to use the
kickstart everytime then.

Yep, done that. It was empty but I just put in a full gallon of fresh
new fuel.

Yep. Checked that and the spark seems nice and healthy.
Have also checked that the is pressure by putting a finger over the
hole where the plug goes and then kicking it. It blew my finger back
from the hole so I guess that means there is pressure (that was my
neighbour's idea).

thanks very much for your time (so far
Mark

 

good to know, thanks.

That's a question I forgot to ask. Where is the choke on this thing.
Can't find it, don't know what it looks like

cool, will try that. thanks John
Mark

 

Hush.

The problem is that 6 volt batteries are very hard to find and very
expensive, and 6V chargers? Forget it.

No, the best bet is to take two 12 volt batteries and connect them in
parallel, then to the bike. This will drop the effective voltage to
six and enable starting. Disconnect before riding off, obviously.

 

Eh ? The voltage of the parallel connected 'driver' batteries will still
be 12 volts won't it - just increased current capacity? Are you talking
about a 'jump starting' scenario, or leaving them connected for a while
to effectively charge the 6 volt battery ?

I think you can get a 6v battery conditioner for about £20, but that is
expensive for the benefit of a monkey bike I suppose.


--

+-----------------------------------------------------------------+
| Pete Fisher at Home: |
| Voxan Roadster Moto Guzzi Mille GT/Squire RS3 Gilera Nordwest |
| Gilera GFR Moto Morini 2C/375 |
+-----------------------------------------------------------------+

 

That is a cruel trick to play on a newby.
You can't get 6v out of a brace of 12v batteries without major surgery.

 

You have a very strange neighbour. He knows how to do a rough
compression check, but can't tell the difference between a 2T & a 4T? I
suggest you move house.

HTH

--
Krusty.

http://www.muddystuff.co.uk
http://www.muddystuff.us
Off-road classifieds

'02 MV Senna '03 Tiger (FOYRNB) '96 Tiger '79 Fantic 250

 

It does, actually. Perfectly.

 

At least you got the point.

<sigh>

 

I have a 6v & 12v trickle jobbie, little switch to swap voltages.

Oh look AccuMate do one ...
http://www.bikestop.co.uk/detail.php?id=1373

not so hard to find

 

They're not expensive - I paid about £11 for the last MZ one I bought -
and 6v chargers are easy enough to get. I've got an Accumate (a 6v
capable sub-Optimate from the same people) was about £30.

Some cheapy car chargers have "6v motorcycle" switch.

 

It's the lever on the side of the carb. From memory, up is on (for cold
starting) and down is off.

The ST70 has a device on the petrol filler cap that seals the vent in
the cap, stopping petrol from spilling out when you put the bike in the
boot of your car. This also stops air from venting into the top of the
petrol tank when the engine is running, which in turn stops fuel
getting out at the bottom and feedin the carb; you need to make sure
this device (like a wingnut type of thing) is in the right position.

If in doubt, try starting the bike with fuel tank cap off completely.

 

UPDATE:
We got it started. See the video I made here:
http://www.yonner.co.uk/blog/141/i-bought-a-honda-monkey-bike-st70

The thing that SEEMED to have fixed it was turning fuel off, taking
plug out, kicking it a few times, then put plug back in, leave fuel off
for a while, then turn fuel back and keep kicking. After 2 minutes of
kicking it started. Then after that it started 1st/2nd kick everytime

It seems quite slow though. I got top speed of about 25mph according to
speedo (and it felt about right). Sounds quite healthy I'd say. The
chap I bought it off said top speed of about 40-50mph. Any comments on
that anyone?

 

*WARNING*
If, like me, you have fond childhood memories of riding an ST70, don't
watch that video. Those memories will now be forever tarnished by the
sight of some fucking chav blinged up with a gold necklace.

<bleaches eyes>


--
Krusty.

http://www.muddystuff.co.uk
http://www.muddystuff.us
Off-road classifieds

'02 MV Senna '03 Tiger (FOYRNB) '96 Tiger '79 Fantic 250

 

It should indeed do about 45mph+. Mind did. Have you got it into top
gear?

 

I thought someone might make a socially ignorant comment like that but
I know you're only playing so I won't hold it against you. By the way
I'm the one at the end of the video trying to do the skid.

 

Yeah I'm pretty sure I'm in top gear. It only has 3 gears right?
I go down one into 1st then up twice into 3rd.
It revs smoothly througout the whole rev-range. The engine is
definately 72cc

thanks again
mark