My cylinder head and other close friends

[Snails]

In the ongoing search for a reason as to why my plug colour has gone so white I decided to drop the front end of my engine and check out the torque of my cylinder head nuts. They were all fine so as I was there and it had been a good few years since i assembled the engine I decided to strip the rest of the top end to give it a once over. Overall everything seems fine to me but I do have a few questions (as always! )

This is my head gasket. It does seem a little oily around the 12 o'clock area - see the brown staining. Could this be an indication it was not sealing correctly?



This is the spark plug hole. It has two smaller holes around (one of which can be seen in the picture below). The other cylinder head I have as a reference does not have these. What are they for. From memory they have always been there so I dont think this is something to do with why I'm running lean, I'm just curious



One of my head nut washers seems to have welded itself to the head. I cant unseat it for the life of me. Again I have feeling its always done this and I have just tightened the nut to it without an additional washer. Should I do anything about this?



Piston pictures just in case anyone can see anything I cant. Looks fine to me so I will just give a bit of a de coke

[psychedelicropcircle]

Warped heed

[Snails]

Warped heed

What makes you say that?

[Snails]

I've cleaned up most of my top end and lapped the head and barrel.

The head looks ok, but the barrel is odd. The centre area is still rough whilst the outside area has gone smooth. This suggests to me that the outer area is higher. Does this indicate a problem or is it just normal? Should I carry on lapping it till totally smooth? Its taken quite a long time as it is. Or is it fine as it is?

Not a great picture by any means but hopefully you can see teh darker banding around the bore;

[corrado]

Whiter plug is definitely a sign of something not right obviously, could be crap fuel but more likely a sign of an air leak somewhere so a leak test would be the best course of action imo.
Small holes in head just look like poor casting and not something to worry about.

[Snails]

Yeah I would like to leak test it but I dont really have the means to do this so have resorted to a component checking method

[corrado]

Yeah I would like to leak test it but I dont really have the means to do this so have resorted to a component checking method

I keep planning on building a kit, just never get round to it. A white plug would spur me on a bit though. Do a few searches it sounds pretty basic to set one up on the cheap. There's plenty of kits on ebay, though more car specific and Darryl Taylor sells a Lambretta specific kit too.

[Snails]

I am interested in what you say about it being a possible fuel issue
One thing I have never understood is why this should start happening as my engine had always been rock solid and I'd never changed anything,
When i built the scoot I sealed the tank with petseal - which I believe is now subject to being affected by the new fuel mixtures
Could it be this coming away in my tank and blocking my fuel flow?
How could I test this?

[Snails]

Yeah I would like to leak test it but I dont really have the means to do this so have resorted to a component checking method

I keep planning on building a kit, just never get round to it. A white plug would spur me on a bit though. Do a few searches it sounds pretty basic to set one up on the cheap. There's plenty of kits on ebay, though more car specific and Darryl Taylor sells a Lambretta specific kit too.

True, maybe I should pull my finger out in that respect. Funds are limited though so dont want to spend too much

[corrado]

Here's a link to Darrell's kit.
£59. Less than the cost of a new piston.
https://www.facebook.com/27012881976792 ... =3&theater