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Gasket Help

Posted: Thu Jun 18, 2015 10:35 pm
by 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.

Re: Gasket Help

Posted: Thu Jun 18, 2015 10:36 pm
by 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.

Re: Gasket Help

Posted: Thu Jun 18, 2015 10:52 pm
by rosscla
Not uncommon to build without gaskets, if faces are good and you need to get the squish / timings right.

Re: Gasket Help

Posted: Fri Jun 19, 2015 7:18 am
by Hughieboy
rosscla wrote: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?

Re: Gasket Help

Posted: Fri Jun 19, 2015 7:37 am
by rosscla
Yes quite often silicone is used or something like welbond or one of the loctite products are used on the head.

Re: Gasket Help

Posted: Fri Jun 19, 2015 11:13 pm
by Hughieboy
Thanks, that's good to know. Got myself some Loctite gasket sealant :)

Re: Gasket Help

Posted: Sat Jun 20, 2015 6:21 am
by 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.

Re: Gasket Help

Posted: Sat Jun 20, 2015 4:13 pm
by shocky
Is thete any engraved markings on the cylinder or head

Re: Gasket Help

Posted: Sun Jun 21, 2015 1:30 pm
by Hughieboy
shocky wrote: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..

Re: Gasket Help

Posted: Tue Jun 23, 2015 4:00 pm
by 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!)