disintergrating base gasket...?

[byron]

I've got a mag flange gasket, bought from MB, same manufacturer, same pattern.
are these ok ?? or not worth the risk...? i was about to use it on my engine, but have other gaskets, so will use one of those this time.

[Ian Hepworth]

Hi All
The reported faulty base gaskets are the black 0.4mm Graftec gaskets, we went from the older orange base gaskets onto the black version as we saw orange ones failing on us whilst constantly stripping barrels on the dyno test bed. Our gasket manufacturer recommended the Graftec material as it should have been far better!

We sold 1000 of these gaskets last year, in January we changed from 0.4mm to the next size up which is 0.75mm (allowing for some crush,
closest to 0.5mm, don't ask me why they don't do 0.5mm). As far as we know no one has complained about the 0.75mm ones.

We have been made aware that the 0.4mm gaskets have failed, in the mean time we have looked into it and now produce a 0.5mm alloy gasket/ packer for the people who are paranoid over the subject.

I'm not counting how many have failed, we knew of 5 at the time there maybe more, but its still a small percentage in the grand scheme of
things.

Today an old Rapido cylinder came in from Replay for a rebore, with a perfect un-broken 0.4mm black gasket! By chance I had to strip my 32hp touring motor to do a few jobs for the Euro and yes it had a perfect 0.4mm black base gasket still fitted to the cylinder! We have had a
few people saying the same.

What more can we say or do, we have listened and done something about it, anyone requiring a newer alloy gasket can have one on request, we will look in your history to see if you have previously had a gasket from us so don't try it on.

The underlying trend to these failures are, erratic running, bad starting, oil leaks etc, obvious signs to a poorly engine, now perhaps
if people checked their head torque setting every now and again these would not fail!

To date we have had no failures of the black mag gaskets and no failures of the orange gaskets on inlet ports, it is a problem only on
base gaskets! Why? Well there maybe a number of factors, the main one being lack of surface area and thin transfers on the more powerful type cylinders, just another bad Innocenti design that we all have to work around!

The RB shown is NOT one of our base gaskets! or one of our inlet gaskets (we also had the RB inlet gasket fail on our dyno test sessions) So its not just our gaskets having problems. Indeed Sticky pointed us in the direction of the green gasket paper as being really good, unfortunately that also fails.

So if you are not sure get in touch.

Thanks Mark Broadhurst MB Developments
01709 869756
[email protected]

[Dazza]

Nowt wrong with a greased up bit of Cornflakes box - kept my PK on the road for days

I like the way Mark snuk in 32BHP Tourer - rub salt into the wound eh

[Train Driver]

Yes i saw 32hp he has only promised me 23hp from my RT255
but well done ian for staying up this late and be very helpfull

[byron]

...To date we have had no failures of the black mag gaskets and no failures of the orange gaskets on inlet ports, it is a problem only on
base gaskets!

thanks, I will happily fit it then

[Speed Demon]

Indeed Sticky pointed us in the direction of the green gasket paper as being really good, unfortunately that also fails.

With respect I pointed you towards a brand rather than a colour.

The brand I said was good is Klingersil. Just looked up the type I've got (and been recommended) and it's this one
http://www.par-group.co.uk/sealing-join ... C4324.aspx
They even do it in 0.5mm

So does this stuff fail, or is it another green (on one side) gasket material you are on about?

[Nic]

I suspect this is a more comon problem than many people realised up to now. In our club, a member's inlet gasket failed on his Mugello 225 last year coming back from C2C weekend. result: bad seize which took out his barrel and required a new crank....

He'd torqued up his head only before setting off 2 days and 850 miles earlier. The feller is also a careful rider and sticks to 50-55ish all day...

[Train Driver]

Are we the only ones (lambretta and vespa) riders who do such high mileages and at speed on air cooled engines, is this and poor fuel quality adding to the failure of engines.
Engine failures have these engines been put together by a dealer/engine builders or by the owners and if by dealer/engine builders what have they said when confronted by these failures

[shocky]

out of interest did the EGT,s on these scoots start to read high ?

[rbgaz]

is there a need to use gasket sealant when using a gasket ? or is it just personal choice ?