Author Topic: Piaggio Ape 50  (Read 14448 times)

1bubble10 (paul smith)

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Re: Piaggio Ape 50
« Reply #15 on: April 24, 2015, 06:41:06 PM »
Ok - I managed to get the head, cylinder and piston off tonight - here are my conclusions on the cause - please feel free to put your comments forward if you think I have got it wrong.

Starting with the spark plug - I think the colour indicates a slightly weaker side of normal (this would cause a small amount of extra heat - so shall weaken the mixture by putting a smaller main jet in the carb.

Bamby P50, Piaggio Ape 50

1bubble10 (paul smith)

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Re: Piaggio Ape 50
« Reply #16 on: April 24, 2015, 07:00:00 PM »
The rings in the piston are intact but are seized solid and badly worn as is the piston. Looks like it has had direct contact with side of the cylinder, at the exhaust port, so excessive heat at the exhaust port. Three things I intend to do here. Change the ration of two stroke oil whilst running in from 40:1 to 30-35:1, I have the heat exchanger on the exhaust (which is close to the point that the exhaust meets the head) insulated - I shall remove the insulation and run the heating fan on longer runs until the engine is run in and freed up. The engine cowl is tight to the cylinder which touches in places. I shall attempt to reshape or refabricate a new cowl which shall increase air flow around the cylinder (I could do this in fibre glass using the old one as a mould with some modifications).

« Last Edit: April 24, 2015, 07:02:12 PM by 1bubble10 (paul smith) »
Bamby P50, Piaggio Ape 50

1bubble10 (paul smith)

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Re: Piaggio Ape 50
« Reply #17 on: April 24, 2015, 07:04:54 PM »
The pictures don't show the scoring in the cylinder very well. However, what is evident too is that the head has leaked but this is probably because the ally head has distorted with the heat.

Bamby P50, Piaggio Ape 50

Barry

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Re: Piaggio Ape 50
« Reply #18 on: April 24, 2015, 07:08:47 PM »
Richer mixture - bigger main jet.
Is there a needle in the carb slide - Is it the right one?
Using fully synthetic two stroke oil?
40:1 seems a bit weak?  Is that the recommended ratio?  Could go to 30:1 whilst running -in
Is the timing spot-on?

Were you going flat-out when it seized?

If the head gasket was blowing you may have heard it 'squeeking'?  That may also cause it to be running weak / lean perhaps as some mixture would be escaping?

« Last Edit: April 24, 2015, 07:11:23 PM by Barry »

richard

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Re: Piaggio Ape 50
« Reply #19 on: April 24, 2015, 07:32:48 PM »
Sure the window cleaner would know how much was a step too far  :D
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1bubble10 (paul smith)

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Re: Piaggio Ape 50
« Reply #20 on: April 24, 2015, 07:57:27 PM »
Richer mixture - bigger main jet.
Is there a needle in the carb slide - Is it the right one?
Using fully synthetic two stroke oil?
40:1 seems a bit weak?  Is that the recommended ratio?  Could go to 30:1 whilst running -in
Is the timing spot-on?

Were you going flat-out when it seized?

If the head gasket was blowing you may have heard it 'squeeking'?  That may also cause it to be running weak / lean perhaps as some mixture would be escaping?


Yes I am aware of a main jet needing to be bigger - just typing faster than I can think.
The carb does not have a needle (very basic carb).
Yes Good quality fully synthetic two stroke oil.
in 50cc its mix is 50:1 - they recommend 40:1 for the 133 - I shall go with 30:1 (i'm happy with that - at least for 500-600 miles).
No not flat out but pushing it some and up an incline too. The engine was not fully run in - only done about 400 kilometers  since the rebuild and I guess I was pushing her along some for quite a distance (so partly my fault).
It does not have a head gasket - ally head to cast iron cylinder.
« Last Edit: April 24, 2015, 07:59:17 PM by 1bubble10 (paul smith) »
Bamby P50, Piaggio Ape 50

Peel replica, Steve Fisk

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Re: Piaggio Ape 50
« Reply #21 on: April 24, 2015, 08:35:01 PM »
On my vw campervan I was running a cylinder head temp gauge , surprising how much the temp goes up and down, all so how much you can control it if you can easily see what's going on

1bubble10 (paul smith)

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Re: Piaggio Ape 50
« Reply #22 on: April 24, 2015, 08:52:20 PM »
Guess I'll see if I can find one on ebay
Bamby P50, Piaggio Ape 50

Peel replica, Steve Fisk

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Re: Piaggio Ape 50
« Reply #23 on: April 24, 2015, 08:59:59 PM »
https://vwheritage.mobi/GB/productDetails.cfm?iItemID=120265 That's the one I have on the camper , but cheaper led ones on eBay

Big Al

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Re: Piaggio Ape 50
« Reply #24 on: April 24, 2015, 09:02:58 PM »
The rings in the piston are intact but are seized solid and badly worn as is the piston. Looks like it has had direct contact with side of the cylinder, at the exhaust port, so excessive heat at the exhaust port. Three things I intend to do here. Change the ration of two stroke oil whilst running in from 40:1 to 30-35:1, I have the heat exchanger on the exhaust (which is close to the point that the exhaust meets the head) insulated - I shall remove the insulation and run the heating fan on longer runs until the engine is run in and freed up. The engine cowl is tight to the cylinder which touches in places. I shall attempt to reshape or refabricate a new cowl which shall increase air flow around the cylinder (I could do this in fibre glass using the old one as a mould with some modifications).

There should be a quoted value for the ratio of a given type of two stroke oil. Not all two stroke oils are the same and the differing types have differing carrying oil, if not mineral. The ratio is not optional. It is a given amount, no less, no more. Run it weak, not enough lub. Run it strong, you reduce the amount of burnable charge, and run a lean mixture.

The answer would seem to be to apply a bit of excess fuel. It increases the amount of lub and cools the engine a little by heating the charge.


If the cooling system is that of the original engine, it is unlikely to cool twice the power without some major modification. It is not info I know, but double the power would suggest doubled the air flow of cool air from outside the vehicle, not recycled air from inside the framework.

Its got rather hot, whatever happened. I hate rubbing strokers in. The more care you take in the early miles the longer/better the unit is. But it is a bit tedious, the temptation to use the power is seductive.
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1bubble10 (paul smith)

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Re: Piaggio Ape 50
« Reply #25 on: April 24, 2015, 09:12:43 PM »
https://vwheritage.mobi/GB/productDetails.cfm?iItemID=120265 That's the one I have on the camper , but cheaper led ones on eBay

Just bought one on fleebay £42
Bamby P50, Piaggio Ape 50

plas man

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Re: Piaggio Ape 50
« Reply #26 on: April 25, 2015, 04:05:09 PM »
overheating/engine seizure , is it a new re-bore and piston ?
if so has the man done his job - I ask because the one on the Villiers kept seizing and when mentioned they swore it was ok , then they remarked on the piston/bore clearance - I laughed , it resulted in me taking the manual for proof of what Villiers recommended .


1bubble10 (paul smith)

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Re: Piaggio Ape 50
« Reply #27 on: April 25, 2015, 06:20:26 PM »
overheating/engine seizure , is it a new re-bore and piston ?
if so has the man done his job - I ask because the one on the Villiers kept seizing and when mentioned they swore it was ok , then they remarked on the piston/bore clearance - I laughed , it resulted in me taking the manual for proof of what Villiers recommended .

No not rebored - brand new!
Bamby P50, Piaggio Ape 50

1bubble10 (paul smith)

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Re: Piaggio Ape 50
« Reply #28 on: April 25, 2015, 06:27:34 PM »
I had a couple of hours in my garage today and managed to fit the new cylinder kit and a larger main jet in the carb. A bit of a spin around the town and some tweaking of the idle mixture screw has her running sweet - I'll take her for another spin tomorrow and then  check the spark plug colour to ensure she is not still running lean. I've attached some pictures of the kit and it all going back together below:-

 
« Last Edit: April 25, 2015, 06:29:30 PM by 1bubble10 (paul smith) »
Bamby P50, Piaggio Ape 50

richard

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Re: Piaggio Ape 50
« Reply #29 on: April 25, 2015, 06:51:14 PM »
I have never known the clearance on a Villiers piston/cylinder i.e. what size piston for what size bore - if its always the same relationship , which I assume ,what is it .
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