TS1 engine One year on.

[Captain Pugwash]

Hi Mark
The link worked, will order the kit tomorrow.
Cheers mate.

[Captain Pugwash]

If anyone is thinking of buying and uses a leak down test kit, then it might be best to keep the test pressures to no higher than 7psi as there's not much point in testing much higher than this, if you did force too much air pressure into the crankcase you might actually damage a seal.

Mark.

[Captain Pugwash]

Update,
Bought some Viton "A" seals for the rebuild, the set I bought are from Reedspeeds.
As the seal plate is out i might as well fit a new drive bearing.

This made easy using the bearing fitting removing tool.





Viton seals large mag seal 52.33.6 and drive seal 50.33.6. Both marked up with another number 2 which to my knowledge is the spring strength.





Drive seal pressed in



Mag seal fitted using an MB seal drift.





Drive seal plate loctite & torqued up.

And the crankshaft pulled in with an MB drive side pulling sleeve.


Free run of the crankshaft checked with a 12 thou feeler gauge.



Crank checked on both webbs for even clearance between case at the top and bottom and also down both sides of the crank webbs while slowly spinning the crank.

[vintage65scoot]

Hi i remember reading that the last number is the spring strength and the number should be above 6 ie 7 or 8 etc.
I say this as i fitted some from Reedspeed and the drive side one lasted all of 1 week. All had to be pulled apart again very annoying . This is just a cautionary tale not trying to tell you what to do as your rebuilds and engine builds are what people should aspire to cheers

[Captain Pugwash]

Hi i remember reading that the last number is the spring strength and the number should be above 6 ie 7 or 8 etc.
I say this as i fitted some from Reedspeed and the drive side one lasted all of 1 week. All had to be pulled apart again very annoying . This is just a cautionary tale not trying to tell you what to do as your rebuilds and engine builds are what people should aspire to cheers

I had spoken to Reedspeeds prior to fitting these, and I also read quite a bit about spring strength and different Viton compounds. When you ask some dealers what type of Viton oilseals they are selling there does seems to be some confusion.

I also have some oilseals on order from MB to try in another engine and I'm going to order from Scooter restorations.

Mark.

[Adam_Winstone]

Mark,

Thanks for sharing this info/detail with us as it could go to helping all of our motors cope with today's fuels.

Adam

[Captain Pugwash]

Hi i remember reading that the last number is the spring strength and the number should be above 6 ie 7 or 8 etc.
I say this as i fitted some from Reedspeed and the drive side one lasted all of 1 week. All had to be pulled apart again very annoying . This is just a cautionary tale not trying to tell you what to do as your rebuilds and engine builds are what people should aspire to cheers

Hi mate,

Your post made me recheck my old and new seals, and it seems I've never used a seal with a higher number than 3 in a Lambretta engine.
The Nitrile seals I normally use on the crank are number 2 for the large mag and drive seals, and the small mag seal its number 3

In the MB seal kit the large Viton crankshaft seals are both numbered 1. They changed the spring strength to a softer spring after customers suffered from failed drive seals on or just after assembly.

But like yourself I really don't want to be stripping down my engine a week after building it just to replace another failed seal, it's a wasted day in the garage when I could be doing something much more rewarding.

But that's the thing with oilseals we usually just fit whatever is supplied, I've never really known what should be in there for the best reliability and I doubt that many others do either.

reading up on Viton seals has given me a better understanding of seals but I'm still no wiser as to which ones to fit for the best results.

If you read up on Viton seals the type ive bought from Reedspeeds (Viton A) are the least resistant to ethanol fuels of all the Viton seals available, so I'm kind of questioning why did they choose them.

There does seem to be very little factual info available to us other than use VITON.

Some basic information stating which type of Viton to choose and why and which spring strength would be helpful.
Plus some basic health warnings that really should go with the Viton seals once they've been used that's just incase they get overheated (300 degrees C) which no doubt some will do heating the mag housing up to remove the old seals at some time.

I would be greatful if you could find any info on the seal springs and if you do could you let me know, as I'm just trying to make my engine a little more reliable.

Cheers, Mark.

[vintage65scoot]

Hi Mark ive remembered where i saw this info about seal spring strenght its in the rear of Stickys Manual page 247 it says the forth number can run up to number 10 and seals with the forth number less than 5 should not be used , but he is talking about Rolf seals more confusion !! Not viton but it i cant see what the difference would be as they are going to reach the same temperatures and assume as soft as each other. I didnt bother putting another viton seal back in as i didnt have one at the time as i had a standard Rolf one put that in and has been in for the last year with no problems .
Good luck hope this helps Mark R

[Captain Pugwash]

Hi Mark ive remembered where i saw this info about seal spring strenght its in the rear of Stickys Manual page 247 it says the forth number can run up to number 10 and seals with the forth number less than 5 should not be used , but he is talking about Rolf seals more confusion !! Not viton but it i cant see what the difference would be as they are going to reach the same temperatures and assume as soft as each other. I didnt bother putting another viton seal back in as i didnt have one at the time as i had a standard Rolf one put that in and has been in for the last year with no problems .
Good luck hope this helps Mark R

Thanks for the reply, I will take a look when I get home.

If sticky has got the right spring strength for us to use then where did he get his information from? I wonder if it's from an old Innocenti tech sheet or maybe an SIL blueprint from when the factory closed ?

would be good to know some more about it.

When I mentioned MB seals failing it's not meant as a dig. And was only one small batch of seals a few years ago now.
To my knowledge he's sold hundreds if not thousands of Viton seals but some time back a small batch were supplied with a stronger spring, and this made it easier to lip the seal on assembly if correct care wasn't taken fitting them.
I believe there were only a couple of failures but MB changed the spring strength back to a softer spring to make it easier to engage the seals over the crank.
I'm not sure which type of Viton MB uses, I did ask but he didn't say.
I'm waiting for some to arrive to try out in a couple of engines.

I know Viton seals are much harder wearing than Nitrile seals so I guess the spring strength might not need to be as high.

If anyone is wondering why I'm questioning the Viton seals were fitting it's because there's much more than petrol going into our engines.
It seems Some Viton seals exhibit better oil (mineral ester & Diester) and ethanol fuel resistance than others.
I just want to know what I'm paying for and if I fit them, that they are the best available for my engine.

Mark.

[Jamjo]

Love these informative threads, keep up all the good work Mark

[soullad]

Hi Mark,
When I built up my TS in 2009, I used Viton seals, but as to what type, spring strength etc I cannot recall. That said all I did was fit on the advice of the supplier which at the time was MB. When I replace the bearings / seals I'll post back on this thread with all the info as these have stood the test of time using different fuels / oils all over Europe since then. I have never been fussy regarding what fuel to put in, but always used the best oil I could afford, often Castrol fully synth.

[Captain Pugwash]

Hi Mark,
When I built up my TS in 2009, I used Viton seals, but as to what type, spring strength etc I cannot recall. That said all I did was fit on the advice of the supplier which at the time was MB. When I replace the bearings / seals I'll post back on this thread with all the info as these have stood the test of time using different fuels / oils all over Europe since then. I have never been fussy regarding what fuel to put in, but always used the best oil I could afford, often Castrol fully synth.

If you can post up your findings that would be great

I think any Viton seals would most likely outperform the standard Nitrile ones now and that's just because of the ammount of additives put into our fuels.

I was hoping to have my MB seals by now only I missed a postal delivery yesterday, so I'm guessing that was my MB seals and they are now waiting in a sorting office.

Cheers, Mark.

[Captain Pugwash]

Rebuilt the top end of the TS1.
Pressure tested and found an air leak at the plug.



Cleaned up the plug seat and fitted a new plug and that fixed the leak so pressure tested again.


It was still loosing pressure so I checked the drive and mag seals with oil.



No leaks but the engines still slowly loosing pressure.

I checked every gasket face spraying with soapy water but no leaks anywhere but it is loosing pressure.



The only thing to check was the pump itself and this is what I found.


I've always noticed a slight air loss using this kit but I had guessed it was loosing air through the pump, but I know the engine is air tight.

After 1 hour the pressure was down from about 7.5psi to 5psi but the only signs of any air leaks are at the pump and tyre valve.

[GP240]

at least its clean now.

[STREETSLEEPER]

Thank you for sharing this Captain Pugwash. This type of thread really interests me as I'm sure it does for scores of others. It's not just informative but you've gone to some trouble to "professionalize" its appearance, and as an auto engineer by profession I appreciate the technical know-how you've shared. I wouldn't describe myself an anorak by any means, and my interest in all things Lambretta has waxed and waned over the years - often spurred on by the appearance of new products and technologies. These new "Viton" oil seals are exactly that to me i.e. new; and the discussions around them about esters and so forth absolutely fascinates me.
I still run my engines on Castrol R40 and so I have my own theories and specialist knowledge with regard to running two-strokes on this type of oil, but since everyone seems to have an opinion one way or another, it often used to be a polemical topic. Nowadays it seems the same controversies rage about fully-synths and esters, the damage they can do, as well as the general effect of running a two stroke on them on a day to day basis. Modern oils and fuels full of additives, detergents, anti-corrosives etc, etc, require modern oil seals, or so it seems. I have only ever had one drive side oil seal go on me, which was on a Jet 200 engine behind an alloy end plate (don't know if these were ever fitted by Innocenti or Eibar, or whether it was an aftermarket accessory? AF tuned the engine when they were in Watford). Revving the engine at a standstill I was enveloped by thick, white billowing smoke, until apparently I disappeared completely.
Your thread would've great for less experienced owners and those with less mechanical knowledge, because it had pictures to show exactly how to carry out a task. I myself found it useful, I wasn't aware that these pullers and extractors can now be bought over the counter. And your conversation about the spark plug made a lot of sense, especially when as you know yourself, but perhaps others are less well informed about, the plug can say so much about the running and condition of the engine.
You clearly relish doing engine stripdowns, but in cases like these they really can avoid potentially catastrophic engine failures. This was an example to others. We may love our Lambrettas for their foibles and idiosyncrasies, but their unpredictability and fickleness means they're always ready to spring surprises on us, sometimes delightful, sometimes maddening. Your early intervention may have saved a lot more bother, and I know I learnt a lot from your topic. I'll keep an eye out in future when your name crops up. Ta Captain.

[Scooterlam]

What he said.
Feel inspired to give my Euro engine a good once over.