Rally 200 modifications

[shipscat]

hi vespasco do you have a plumbers blow torch or a small butane,propane+oxygen kit for welding ? if you have , give the flywheel boss where the rivets are a rite proper toastin you need intense heat fast so you expand the flywheel boss quicker than the crank
with your puller efin tight as you have it give it a sharp tap with a hammer it will come off
if it gets hot enough it may even come off by itself without the hammer don't worry your crank will be un-harmed

[vespasco]

yeh ive given it heat, along with doing all the rest at the same time.
It is a little tricky to heat up as the ali flywheel takes a lot of the heat away.
I'm going take it to someone with a welder and weld and old flywheel puller to the flywheel and try that way. Although I am a little worried that it will splay the threads on the crank? (Becasue I know it will require a LOT of torques)
I checked again today as i've left the pullers on now for 48hrs, gave it another blow with a 2lb hammer. Still hasn't budged.

Other wise I will have to drill even more holes in the centre bush, hoping I manage to release some pressure.
Next plan is to grind off those rivets completely, leaving just the centre bush. Just maybe I can get a better, stronger hold of the flywheel.

If not I may end up trying to cut it off, without making too much mess, somehow.

Keep the ideas coming


*I just thought. If i've got to take my scooter to a welder then he will also no doubt have oxy/ace too. That will be a lot quicker and hotter than my tiny blow torch. Good one shipscat. Worth a go, as the pullers are still trying to pull that flywheel off as we speak.

[shipscat]

yep it's getting to special tools now don't fu*k about with it anymore
i'd ask your welder if he has oxy/acetylene if he hasn't he will have a tig set ask him to heat the flywheel boss with the tig torch same as he would with the oxy set
don't forget to take your pullers too but you may end up having to weld one after all
i strongly recommend you stop with the drilling you have a good chance of making things worse

[henri]

i think my last gasp idea would be to grind the rivets off an just attack the centre ,but your chances of getting ali fly out the way without harming stator are slim . H

[sime66]

i hope you make some progress with it this weekend, vespasco.

[vespasco]

No progress at the weekend.
But today there was.
I took the vespa to a local garage, borrowed a welder and welded the flywheel extractor to the flywheel.
I took it gently with the welder to begin (and as it was set up that way) but the small weld started to give when I really gave it some with my spanners.
So, I welded it properly this time and got my spanners on it again....
No go...
I couldn't quite get enough leverage but then the spanner gave way...


As I was in a proper workshop with proper tools I asked to use a proper spanner...
I levered that until my hands couldn't take it...
No go
So I asked for another proper longer spanner and..
It still took some budging then I heard something give...
it didn't sound like the flywheel popping off
but
YES, it was the flywheel! Finally! It's off!

Now the easy bit! (hopefully) and change the kickstart cog or whatever it is thats knackered

Is there anything I can do/ to my flywheel or crankshaft before I fit my new flywheel, to help make it come off easier next time?

[shipscat]

i use 3in1 ptfe spray on the the crank and in the flywheel taper seems to work for me

[pxguru]

Well done! Knew you would get it off. Hopefully the next one stays on until you want it off. That was extra tight. The next flywheel will not be the same.

[djloone]

does look like a epic battle mate...well done

LOON-E

[jedihunter]

Now that is a proper trophy! mount that on the garage wall as a monument to perseverance. Well done!

[vespasco]

Thanks guys. It was a struggle for sure.
If that flywheel was lathed down a touch and re-balanced it would still be usable. It's not as mashed up as it appears.

Well, the next flywheel will be even tighter I imagine, as it's brand new. And the Pinasco crank isn't going to get any smaller either.
I may just lightly wet n dry both flywheel and crank.

I have tried a touch of grease in the past but am not convinced it helped. I seem to remember it had to be re-torqued too often.

I'd better pressure test this time too, before i fit the flywheel.
Now, where's that rubber ball i used as a bung for the exhaust stub!?

Talking if which....was it around 10psi for 5-10 minutes with no/very little loss?

[vespasco]

The engine has been split open and the kickstart mechanisms examined...and I could not see any problem whatso ever with any of it, even through my jewellers loupe.
I was kinda hoping to see a mashed up kick start cog but I found nothing out of place....but...maybe, possibly, the spring was out of place, at least it was when I had the flyside crankcase half in my hands after splitting the cases.
So maybe it was just the spring dislodged.
The actual problem I have is like the kickstart is getting stuck.
Sometimes, randomly, hot or cold, the kickstart just would not turn the crank.
It kinda feels like the piston is jammed for example.
If I really stand on the kickstart hard then something will surely give, it feels like it wants to twist the kick quadrant because somethings jammed.
So, I reluctantly re-assemble with the new kick cog and spring I'd got prepared.
Re-assemble enough to feel some compression on the kickstart and ....
The first kick, same again, like something is jammed or does not want to budge one tiny bit.
I can move the flywheel relatively easy by hand.
Try again and it starts first kick.
Sometimes I rock it in gear to try and free something but that does not always work.

Since I've rebuilt the vespa 20,000 miles ago it never had such an issue. Although I have modified it some what.
So, before I split the cases again and re-check that spring is in it's proper place, has anyone got any other suggestions as to what it could be or what I should be looking for?

[vespasco]

Could this problem be something to do with compression?
Ive noticed by looking at the flywheel, that it would only jam when the piston is around 40something degrees BTDC.
So I gently pulled the flywheel round to it's next 'resting' place, to just after TDC and the kickstart is never a problem.
I guess because there is not so much compression.

So what can i do about it?

[pxguru]

A jamming kickstart should be fairly easy to spot but the fact you can't see it means it is not a usual problem. There is nothing actually jamming or it would not ride. This rules out all things similar to bent cruciform. As it seems like it jams at the compression stroke, then something is bent or worn with the kickstart cogs. Could even be casing wear if your engine is original early 70's. If yours are old Rally 200 casings then most had a metal sprung flap instead of a coil spring. Was yours changed or is it a P200 motor?
Anyway, my top guess is the little hole that the quadrant pokes into in the main casing. I reckon yours is all baggy after kicking that Pinasco compression monster for so many years.

[henri]

1 idea , your getting old an just cant manage a high comp/custarsised engine anymore .time for a mobility electric scoot or electric start . only kidding .
ive seen twisted o-rings binding on the kicker shaft ,an bent shafts binding in the cases ,but yours is intermittent problem . so unless its a combination of that an piston coming to rest just at start of comp stroke adding up to no-go with kicker .i'm out of ideas . H

[sime66]

Longshot, but maybe worth a mention:

Not sure what bits you’ve changed, if any or when, but there’s two different sizes of 12x12 kickstart gear I think (Ø20.5 & 21.8mm); you haven’t swapped it recently have you? Your Rally should be Ø20.5mm; maybe the bigger one would skew and lock up sometimes? – Or maybe yours is correct, but worn inside and not engaging straight?

www.sip-scootershop.com/ersatzteile/Vespa%20PX/Gear+Box++Input+Shaft-246?model=ded4f83a-6617-42d6-88cf-fff7343598d7

Probably nonsense, but it seems any ideas, however unlikely, might help at this stage.

[vespasco]

I have early p2 engine casings (The 2nd set) built with the best bits from the modern px.
I do still have the original cases for the vespa and did rebuild it (with the flat spring yes)
Then decided I wanted the modern upgrades available like ducati ignition, EFL gears, 12volt, clutch etc etc and the list got bigger with the Pinasco.

The compression has always been on the conservative side.

Now I've ridden it a bit more at the weekend, and started it more, I can confirm that it is not turning over but only when the piston is resting near the top of it's stroke, under full compression like you say H (there's plenty of kick in me as yet and when there ain't, my mate has already built me a mobility scooter with some bizarre chinese 2 stroke engine custardized into the frame).

So how to get over this 'problem'?
Lower the compression a touch? I have lapped the head quite a few times so that's a possible cause.

But when I checked the piston.....that's probably added a c.c. or two to the combustion chamber volume! That thing now has a shallow inverted dish in the top. That's going blow one day if I carry on like this. That doesn't help cooling either.

I've double checked the those kickstart gears. I was kind of hoping for a Doh! moment as I pulled out a 12/13 cog but no, it was the correct one and showed no signs of jamming, jamming, jamming, jamming and it looked just like new.

Plug wise, still white
Currently running
(BGM FF si26)
50/140
160 BE3 150
Rally slide - no pockets on top
Ran pretty well with a 148 m jet
Not so well with other atomisers, feeling rich
But plug is always white
So back to a 150mj. Thats about as ridable as I can keep it.

It feels like it's lacking and the tone of the motor is not quite right.
It's still not quite right yet but rain stopped play, the flat tyre didn't.

Next thing, which I keep forgetting to do....BE9 plug. I'm sure it will help.

Since fitting the new flywheel I retarded the timing as little as I could, just to keep it on the safe side of possible pinking problems, which happens sometimes. My piston is proof of that.
I do need to check the timing so see if the new flywheel put it out a little. That job is on the list.
It's at the MOT station overnight, with no prep and an almost bald tyre....
I had in fact swapped that for my new spare at the weekend. I went out to do some plug chops and play with the jetting. Coming into a roundabout, a few cars around, I went around the roundabout and ended up drifting round. Holy fudge! The back end was out like J-lo. I though it was the new tyre not quite run in yet or something and so I pulled over and had a look. I had a flat. How I stayed on I'm not sure. It was like I was on a dirt track on a MTX bike going round that roundabout, I was leaning a bit too. I can laugh now. haha

[henri]

least ya lived long enuff to laugh , 1 thing J-lo aint is flat , like ya style my man , keep jamming it til ya cant eh . 1 thing ,ya reckon a be9 will cure ya ill's , sorry not so sure .H

[pxguru]

Did you check if the kickstart quadrant was a sloppy fit in the main side casing? I'm sure that's it. Can easy put some bushing in it, if it is.

The running weak is a worry. That's not normal. Did you put in a new 160AC or re use your old one? The one you are using may be drilled out at some time.

Are you running tubeless rims? Anything fast really should be.

[vespasco]

To be fair, I didn't really check for a sloppy fit as such. I checked it all it was spinning smooth and easy. I didn't notice anything like that but will surely have a closer look next time. There's no leaks through there either.
Yet it does ALWAYS 'jam' when the piston is resting under full compression. If I try to stomp on it that is.
I have to very gently and slowly press down on the kick lever to get rid of that compression.
And it never jams when the piston is resting elsewhere before I attempt to kick it over.
The cases had only around 6000 miles on them before I custardized them, not many miles ago.

Good point about the AC. I'll check and change that to be sure.

I still think it's the piston being under high compression before I attempt to kick it over that's causing the problem. I'm having flashbacks to this happening directly after I ported it and changed the crank. Although it only happened once. Then it slowly started to be a p.i.t.a.
And to be fair I've not done a great amount of miles on it since. A few good runs but it was stored away for half the year...and it might be stored away again soon... I'm getting fed up with work.

I think I should measure my actual compression again. Somethings changed.

I'm also debating on when I should buy and fit a new piston.
There must be around 2-3mm off the top of that piston crown that's disappeared. Which explains the grey colour on the plugs.

I'm wondering how thin the crown is too? It now has an inverted dome to the piston crown, about 30mm diameter. Not good.

I need to revise my carb situation too. Once I've checked the timing again.
Those si26-er's don't like my slightly ported Pinasco.

[pxguru]

Makes sense that kickstart jams at compression. Pushing on it moves it out of line.

I would get it running richer before changing the piston through choice. Need to try a different AC160 before I can think what else it might be.
How did you get on with the crankcase pressure test?

[vespasco]

I knew that question would crop up.... I haven't actually done it yet!
I will. This weekend.
I split the engine in the garden, ala sime66, and my 'compression testing kit' was in my lock up.
But then I kinda think...There's certainly no lose of compression in the crankcase as it would surely give when the kickstart problem arises.
It's like I'm already doing a compression test when the kickstart start problem arises.

It passed the MOT with an advisory for the rear tyre.

[vespasco]

Update;

Compression test done
The results;
Firstly, my small foot pump only has a tiny dial that reads @ 1.3bar when it should read 0bar
(I have to use the bar scale as psi is too tiny to read)
I pumped it until I could feel that the crankcase was full as I could barely push down on the sensitive pump. This gave a reading of 2.3bar on my gauge but I will calibrate that to back to 0

1bar = 14.5 psi

Starting with 1 bar of pressure....
After 1 minute - 1bar / 14.5psi
After 2 mins - 0.9bar / 13psi
3 mins - 0.8 / 11.6
4mins - just over 0.7 / 10.3
5mins - just under 0.7 / 10
6mins - 0.55 / 8
7mins - 0.5 / 7.25
8mins - 0.45 / 6.25
9mins - 0.3 / 4.35
10mins - 0.3bar / 4.35 psi

Then I pulled out the exhaust bung and a small gush of air came out, so there was still pressure in there.
Does that seem reasonable to you guys?


If you want to know what kind of readings to expect when there IS a leak....well, on my first attempt of this compression test I forgot to tighten the spark plug (a modified spark plug for the compression testing kit)..so it was loosing pressure slowly at the following rates...

Starting at 1bar / 14.5 psi
After 1 minute - 0.7bar / 10.1
2mins - 0.5 / 7.25
3mins - 0.4 / 5.8
4mins - 0.25 / 3.6
5mins - 0.15 / 2.2
6mins - 0



Re-torqued everything again.

Fitted a new inner tube. I found out it was the valve that had leaked when I got a flat the other day.

I've checked my timing and that remains the same, @ 19 BTDC
(and the new flywheel comes off relatively easy!)


Jetting is now totally changed, probably due to the weather today, rain, although it's still warm.
si26 - 55/160 idle at the moment....@ 2.5 turns out, plus another bit.
160ac BE3 152mj
Slide no.4.0
Ran great with a 150mj but want to be on the safe side of great so using a 152 and still runs well.
If I go for a 155 it's too rich and not so pleasant to ride.

It revved out smooth in all gears.
I tried a few dyno runs but it was a little windy for accurate results and the recordings weren't great.

In this weather today, drizzling rain all day, the vespa felt like it should. Quick, sounds nice, rides smooth in all gears and I can ride it keeping in 4th gear all the time.
Rpm compared to MPH, when in 4th gear is back to normal too, or maybe even a little better.
For eg, if the rev counter displays 4000rpm - my speed will be close to 42pmh
If the rpm displays @ 6300rpm - I will be @ 65mph
I seemed to have gained something for nothing...but will put it down to the ideal weather conditions...except the rain. I could not find my neck/face tube thingy and my word, my face was f#@k'n stinging in that rain. (I use an open face helmet) It was like having several pin cushions rammed in your face.

[vespasco]

I've been out all hoping to pin down the jetting.
I tries all sorts of combinations. Some felt better than others but they all felt a little spluttery, not so smooth.
And I ended up going full circle back to where I started! 55/160 160/BE3/152

I finally swapped the plug for a B9 and the plug is showing signs of colour!, not much but it's a good start.
Yet, with the B9 plug I found it difficult to max out @ over 70mph in 4th.
Is that possible that a colder plug could do have that effect?
Or maybe I need another re-torque as I feel like its loosing a little power in 4th.

Good news though, I bumped into a biker who had lots of vespas in the past and he happened to tell me the legendary tuning wizard around here now has a dyno
What's more its only about 3 miles from me :0
And further more I happened to bump into said tuning wizard in a local shop and more or less made an appointment
I'm hoping to experiment a little, if he has the time and I have the money!
I want to see the difference between the SIP roads mkl and mkll
And I'm hoping I'll be able to see the effects of different atomizers aswell as main jets.
Also I'd like to compare the si 24 and si26 carbs.
And I'm hoping to record all the runs on Micro Dyno so we can see how accurate it really is
I'll keep you posted. Likely next week.

[pxguru]

This running lean is a worry. They Dyno will really help if you get the time on it.

Compression test is not perfect but not causing this issue for sure. Air leak would have to be way bigger. I am remembering your inlet timing is near standard, apart from the Pinasco crank. Is that right? Trying to think of why yours is so different to mine and Sime's. If you have put in a new AC160 and it is still the same, the next thing I would do it try an AC140 and see what happens. That will certainly fix the running lean at WOT issue. Would be nice to get it really close on "seat of the pants" before going to Dyno.

I have found that running lean goes great for a while but as it gets hotter and hotter the performance goes away, starts not to rev as high in each gear, and soon after that a hole appears in the piston crown

[vespasco]

I've been thinking about that inlet...
The timing is only is not so crazy
but
I'm wondering if my opening up the tract in the inlet on the cases...
I kinda made an almost straight line between the top of the inlet tract to the bottom of the inlet tract
I'm beginning to wonder if that's what's making the difference!
I can only guess that with the si 24mm, with the air flower a little faster, that it sucks more fuel through.
With the 26mm, maybe there is just too much air in there for too long and it can not quite get the pressure it needs.

I'm hoping to make time to fit my 24mm back on tomorrow. I'm sure that was fine, gave a good plug etc.

I tried the 140 ac but that was too restrictive

I've ordered a new piston but do i fit it before or after I play on the dyno? As it will alter my compression too.

The dyno may not be so important after i fit the 24 back on anyway.
Time is running out.
It's getting cold and I'm in need of some Bhutan whiskey. Best drunk in Bhutan

[vespasco]

si 24 back in with drilled out feed hole to 1.8mm
idle is 50/160 which is a little rich
160 be3 152mj
all runs smooth and ok...
150mj is on the ragged edge

BUt I still have this white plug! anything after 1/2 throttle

Ok. It could be a clutch seal
or
it could be a hair line crack somewhere, which i've always suspected since last year.

I've changed engine cases, next to try is the head, then the piston, then cylinder!

The plan now....

I may just try to get it running with 140ac and 162mj, try to get some colour @ anything over 1/2 throttle.
If not, change the pipe to the sip mkll road. That eliminated any pinking I had before. So could prove useful. The mkl pipe is getting old now I guess.

[vespasco]

Had some fun today. Went to check out this running lean problem today, opened the doors of the 'shed' and noticed a big pool of petrol on the floor!
Turned out it was the Sip fast flow tap, it would not shut off. It lasted a year.
I tried lapping the shut off valve that seals onto the rubber seal/washer but no go.

When I have the time I'm going to swap a few bits of the Sip tap with some other taps I have, until I see what the problem is. I can't quite recall why it doesn't shut off. I know we spoke about it.

The tap swapping took all afternoon. I had over 7 litres of petrol in the tank and only a 2 litre container of any description to poor it in.
So I drained off 2 litres and drank the rest.
No not really. I left the rest in there. Turned the tank vertical with the filler hole at the top and somehow managed to change the tap without loosing too much fuel!
It was easy getting the old one off but trying to flick the nut onto the taps thread with my extra long screwdriver wasn't so easy but I done it in the end, after the nut and washer dropped into the tank.

Then a lot more faffing about trying to re connect the fuel pipe to the tank, as I'd cut that as short as possible when I was having problems with the BGM tap Feb 2015. So that's on the to-do list.

So I got the stock rally tap back on and I know it will flow 11.5 litres per hour with a cosa top fitted.


==============================================================
f.y.i. - (I done some experiments last year, with fuel flow)

The stock Rally tap, with just a 530mm fuel line hanging down, flows 12 litres/hr
The SIP FF flows 19 l/hr with just the fuel line hanging down

With a cosa float bowl top fitted, the one that uses the larger 5.2mm sprung needle,
the SIP FF flowed @ 12.9 litres/hr
With a stock float bowl top with the smaller 4.5mm needle,
the SIP flowed @ 11.5 l/hr

And without the needles fitted they both flowed 13.8 l/hr

The little round mesh filter has no impact whatsoever on the amount of fuel flow.

I can also add that 6.9 litres of fuel per hour will be ok around town and up to, approx, 1/2 throttle.
==================================================================================


I took off the carb today, to clean up the over flow of fuel. The needle is ok. I put it all back together.
Ended up using a 55/160 idle.
and tried, for a laugh, the 140ac and 162mj... that was way too rich! excellent!
back with 160, BE3 and 148,, still way too rich! excellent!
Went down to a 142, still a bit rich an needed tweaking but getting close! excellent!

But still had this white plug at 1/2 throttle

Anyway, as I was looking into the back of the carb, breathing in petrol fumes, adjusting the mix screw, there was a little fuel at the back of the carb, from when I re-fitted the fuel pipe, and I noticed it being sucked into the carb! Not much but that thin layer of fuel was definitely moving as I revved the motor!!
So that carb box is coming off tomorrow and being replaced, if I have a spare. It was from a 150 super I think, originally, so has been modified to fit the Rally and si26. Maybe it's that that has a crack in it!
Or it's warped.



Anybody have a spare carb box bottom half, non auto lube, any P/X range will do as I will open it up a little to match my cases, so long as it's not auto lube.




Imagine that, I'm running a 142 main jet! And it's rich! That's good news!
I think I'm getting somewhere!

[sime66]

Glad you’re sort of making progress.
Noted your previous post that you’re back to Bhutan soon too; have a great time.

To business:

It was the base of the vent pipe on the SIP tap that gave the leak when the tap was closed – fuel in through there bypasses the tap.

I have several spare non-autolube carb box bottoms; an old No2, and a 3A and 3B, (which both also say 99041). It looks to me like the 99041 (they look the same to me) are already opened-up for a 200, or the older one would need more work, but would certainly not be too big to start with. Photos below; I can post something to you in the morning – I’d prefer to keep one of each if you can use a 3:

[vespasco]

Wow! Cheers Sime... thanks a lot. The smaller one is nothing a dremmel could not sort out. There looks to be enough room there.... but I actually found one this morning!
The one I took off sounded a bit dull when I tapped it. The 'new' one had a much better ring to it so I'm guessing there's no cracks in that.
So lapped that, cleaned it and fitted it.

None of which made any difference.

I can get the motor running very sweet with the si24, rev out to max in each gear and also make it feel rich but still the white plug with anything over 1/2 throttle.
That Dellorto licensed spaco si24 is so much easier to set up and more precise with the adjustments on the air mix screw than the si26.

Working on the theory that using a smaller AC than the MJ should get progressively richer I tried the 140AC....with a 158mj and there was a little sign of colour!
but it ran like crap and would not rev out.
With the 160AC it would be lovely and smooth and rev out ok.
I also tried the 140AC with 162MJ combination...it ran much better on the si24 than the si26 but not so usable.
So I drilled out the 140AC to 1.50mm. Hoping for a compromise. Keeping that MJ bigger than the AC.
It was better for sure, smoother than the 140 too, I could almost get it to rev out but the atomizer would need changing to get it smooth at around 4000-6000rpm.


I also drilled out a 52/140 idle jet... which is now a 52/150
The 55/160, 50/160 and 52/140 were all showing too rich on the mix screw...just 3 x half turns out.
So I made the 52/150...quite alright! 5 x half turns out...picks up and starts ok. Maybe a little rich if anything as it didn't want to start on 1st kick sometimes when warm. I'm just waiting for my drill bit set to arrive...next I will try drilling the idle to 1.55mm, then if needed, to 1.6mm.


I think I may just swap to the sip road mkll...I'm sure it runs cooler and may even like the little advance of ignition timing I think I have.

I'm not convinced my timing is correct either at the moment.

Still lots to do

The plan for tomorrow;

Still with the sip mkl
Re-torque everything
Set it up by seat of pants again
likely use 52/150, 160ac BE3 158mj
Plug chop


Swap pipes to mkll
set it up etc and hope for the best