Gasket Help

[Hughieboy]

Hi All,

I've just stripped the top end off my Harry Barlow tuned 190(?) Li150 engine to a) give it a decode and b) find out exactly what's in there as I bought the motor with the scooter and didn't have the work done myself.mive asked a few questions before but couldn't answer accurately because I didn't know what I had.

Anyways, it all came apart nicely but is pretty coked up in the head and on top of the piston. The thing that concerns me is that it either doesn't have a head gasket or its so thin and stuck to the head that it's hard to tell as there doesn't appear to be a lip. There was a small trace of sealant however around where the gasket edge would be.

Being a novice at engine work, I'm wondering if it's possible that there is no gasket? I don't want to dig around trying to find an edge and consequently score the sealing face of the head. Equally, if it is there but so thin well stuck as to be imperceptible, should I just reassemble it as it is? And should I use any sealant?

Has anyone any ideas on this?

Thanks.

[Hughieboy]

Just to add, I don't know what the piston is but it doesn't look like a Lambretta one. I also tried to measure the con rod in situ so not accurately, it's says MMC on it and is approx 117mm centre to centre.

[rosscla]

Not uncommon to build without gaskets, if faces are good and you need to get the squish / timings right.

[Hughieboy]

Not uncommon to build without gaskets, if faces are good and you need to get the squish / timings right.

Thanks.... Would any sealant be needed on reassembly?

[rosscla]

Yes quite often silicone is used or something like welbond or one of the loctite products are used on the head.

[Hughieboy]

Thanks, that's good to know. Got myself some Loctite gasket sealant

[LI225Canada]

Make sure you are using a liquid gasket, gasket maker or gasket eliminator type product (Loctite 515) and not a gasket dressing product which is meant to be used with a normal gasket.
I just used Hondabond4 on my cylinder base and head. So far so good but it has only been 20miles or so.

[shocky]

Is thete any engraved markings on the cylinder or head

[Hughieboy]

Is thete any engraved markings on the cylinder or head

There appears to be a "1" or straight line on the head gasket face of the cylinder (unless it's an old mark but it looks like its engraved). It also has the innocenti i/j by the exhaust port with a line underneath it. The cylinder head has FPB and 150 stamped on it..

[Boreham]

Having Known HB for years and all my engines come from him, he tends to use wellseal on on the head/cylnder joining surfaces (he has on every one of mine!)