aprilia rs50cc moped problem

[normspanners]

I appreciate any help on this one, it is bugging me, but i also want my nephew to learn from it, coz thats how I learnt, my dad helped me greatly, he was an engineer but mostly from my experiences from my tens and havnt mispelt teens HA.
I remember my first bollockin when i was nine/ ten for carring on undoing the brake pipe, on the hillman when helping replace the wheel cyl , when my dad said wait, I will get some release agent on it I thought, but its undoing, it was, and we had a loverly twisted brake pipe and no brake flaring tool on a sunday. I was not very popular. That was in the days of single circuit brakes.

 

[Wallace]

Getting the truth as to what has been done to the bike out of the previous owner if they are a teenager can be hard work as they don't want to look stupid.

 

[normspanners]

Does this diagram correspond with the wiring? If the sidestand & kill switch are isolated by disconnecting the red/white wire from the coil and the fault is still there it only leaves the ignition winding and pickup in the generator or the coil that can be faulty if the spark is weak. If the mains were that bad the pickup airgap might have opened up if the plate has moved or been damaged.

Cheers wallace for the WD very similiar to the haines man. and yes I have disconnected both the yellow and red/white and everything on ign is new apart from the flywheel.
but the aprillia kit has stator flywheel and includes the stator mounting plate which does appear to be timing adjustable, but IIRC is not slotted on the bike.

 

[normspanners]

Getting the truth as to what has been done to the bike out of the previous owner if they are a teenager can be hard work as they don't want to look stupid.

Lloyd the nephew is 16 and loves bikes and cars, but I couldnt go to look at the bike when he bought it, a young lad from the garage went with him, a little impetuous,HA teens EH, the owner was not available, HUM!!, just his mother, who said, oh he said you might have to bump it as the battery is not fully up.HUM.
Hes now not returning messages. So now its the nephew who looks stupid .
But I'm gettin the flack for not fixing it coz hes back in ma's taxi.
or staying with us which I dont mind coz its nice to have someone to talk to about real things like cars and bikes .

 

[normspanners]

One thing I had thought about the stators are aftermarket and the coils to flywheel gap is pre- set ie not adjustable, if that tolerance is not exactly as original spec, then we might be suffering low voltage because of the air gap,if it is not correct ie larger.
Only it has made me think that the mains where VERY worn, 1-1.5 mm , but there was no witness marks of rubbing I would have thought the air gap should be less than 1mm.

 

[AndyStobbs]

Its a wonder it ran with that sort of wear on mains. Got the scope here, if you get stuck. Its a hike I know, but could well prove worth the time outlay to see a trace of primary voltages vs secondary all on the same screen.

 

[normspanners]

I agree I was shocked when I saw it.
Cheers Andy that sounds the biz i could wack it on the trailer, could you pm me your number.
Thanks, it would be nice to meet you anyway,-------- then if I can help you etc etc.
Norm

 

[normspanners]

Right an update on this, checked the kv on the spark plug min 10kv max 18kv on cranking so thought this was reasonable for starters, but would not start on the button when bumping would go to 21kv. Rode the bike and was sure it felt weak, checked the compression on cranking 95 not too bad for a cold stroker. Now he had ordered jets for it so we stripped the carb but jets where the wrong thread and too small !! so decided to drill the one that was in i got my jet drills and checked the sizes and found that the one in the bike was .95 smack on .95 drill, next drill was 1.0 too close I thought so next was 1.2 tried that and it ran better but not perfect by far, it still needed the choke to make it pull so lets go bigger, better again but not right, 4 stroking in mid range but hitting powerband with clutch dabs , tried another plug but still not right then tried a short reach plug and it ran better. Various plug chops showed still weak so bigger on the main again finally ended up at 1.4 now was running reasonable but still not clean .
in desperation pulled off the flywheel to look at the stator again, and to see if I could adjust the timing coz the replacement kit have now got slots in them. I inspected the stator and was not happy with it it didnt seem to be connected up correctly and was not a tidy wind the wire was smaller than the original so ended up refitted the original,
Well F me ran clean and starting off the button but still looked weak then thought about the sort reach plug was forming a sqiush area in the head Now many years ago Greeves racing came up with a squish head and it allways showed weak on the plug, to do a mixture check we had to take the head off!!
So in went the long reach again no new ones at this point just a well used one and bingo running sweet pulling me 18st from low down to 50mph max available on the short industrial estate without a hickup ,21.30 hrs at this point enough for a sat night.

 

[octo0072000]

glad you are getting it sorted
so by the sound of it fancy exhaust fitted never run right since kid sold it on as couldn't fix it your kid got his leg lifted and you got lumbered to fix it
i wonder if your kid has learnt anything from it

 

[normspanners]

Thanks for that,
Yep I think he is learning, he is a good lad and listens to me and does come up with good answers it is hard because I have forgotten more than he knows and I have to reteach myself at the same time !!
I am trying to teach him the old school way because he can learn the modern stuff from college but there is a MASSIVE gap that cannot be filled by the modern way of computers etc that not many people can fill.

 

[norlander]

sounds like a result-nice job mate.

 

[Wallace]

If you are having to go up that much with the jetting I would suspect the "new piston and pot" is a 70cc big bore kit.

 

[octo0072000]

Thanks for that,
Yep I think he is learning, he is a good lad and listens to me and does come up with good answers it is hard because I have forgotten more than he knows and I have to reteach myself at the same time !!
I am trying to teach him the old school way because he can learn the modern stuff from college but there is a MASSIVE gap that cannot be filled by the modern way of computers etc that not many people can fill.

i know what you mean about reteaching yourself i hate can-bus mine C8 is not talking to me has had lots of faults still runs but now in limp mode i only bought as spares & repair getting there so now starting to go through the wiring that's the problem with computers this fault code means ?????? but could be lots of other things
all good fun

 

[AndyStobbs]

Post up your Canbus issue octo and I will try to help.

Norm, so whats the upshot? Too weak on the jetting and a worse than original stator?
95psi is right on the lower limit I would say.

 

[normspanners]

Yep had a nissan DPF to work on, had several codes one was air conditioning 'Oh ignore that' turns out that nissan or renault have used that same P code number for their DPF.
Got a merc at the moment telling me 1 malfuntion battery alternator, but when checked manually and with diagnostics has no faults water cooled alternator £300 + how to advise customer?

 

[octo0072000]

Post up your Canbus issue octo and I will try to help.

Norm, so whats the upshot? Too weak on the jetting and a worse than original stator?
95psi is right on the lower limit I would say.

thanks Andy will do will do in a new post main point is got to get it talking to lexia first i think it's wiring
at present

Yep had a nissan DPF to work on, had several codes one was air conditioning 'Oh ignore that' turns out that nissan or renault have used that same P code number for their DPF.
Got a merc at the moment telling me 1 malfuntion battery alternator, but when checked manually and with diagnostics has no faults water cooled alternator £300 + how to advise customer?

trouble is you change the alternator and still end up still with a fault then you are stuck with £300 quids worth of non returnable stock all depends on the customer could run it or would it shut it self down ? can you not go into can-bus and tell it a new one has been fitted ?
(i want a moggy 1000)but a good one is too dear minimal electrics

 

[normspanners]

Norm, so whats the upshot? Too weak on the jetting and a worse than original stator?
95psi is right on the lower limit I would say.

The bike now runs, I find it hard to see why it needed to go so big on the main but it is at least safe at mo, it is starting off the button but didnt check compression after it was hot. I have it now at least ridable the stator was definitely giving a fault i looked at the flywheel and it seems to be just one big radial strip magnet with one main join , seems to have equal magnetism all round but how does the ignition pick up know when to fire the cdi ?? unless when the join goes by ?I was cold and wet from riding it up and down and had not had much food and 9.30 sat had had enough and I am sure so had the neighbours!!! I agree re the compresssion but wasnt takin the head off he can now ride it !!

 

[octo0072000]

back to the bike sounds like new stater not much good
shame you didn't measure the bore when you had the head off
but as Andy said could be a badly fitted big bore kit with exhaust and carb
or all sorts of variables think i would be knocking on last owners door for a update of what was done if no sense there
well at least you tried
without rereading thread has it still got original airbox and filter

 

[octo0072000]

The bike now runs, I find it hard to see why it needed to go so big on the main but it is at least safe at mo, it is starting off the button but didnt check compression after it was hot. I have it now at least ridable the stator was definitely giving a fault i looked at the flywheel and it seems to be just one big radial strip magnet with one main join , seems to have equal magnetism all round but how does the ignition pick up know when to fire the cdi ?? unless when the join goes by ?I was cold and wet from riding it up and down and had not had much food and 9.30 sat had had enough and I am sure so had the neighbours!!! I agree re the compresssion but wasnt takin the head off he can now ride it !!

the join may be the trigger

 

[normspanners]

good point on the overbore guys I will have to check and do some measuring but at least now it goes and for a '50 ' goes quite well.