SX 150 gaskets

[wack 63]

I am rebuilding a SX 150 motor and noted that it uses 2 head gaskets and that the old 6t's tuning handbook says not to remove one gasket as it reduces power. I will be checking the squish clearance and wondered if I must use 2 gaskets and the reason why?

[scooterslag]

When I rebuilt my SX150 engine a couple of years ago - I had to run just one gasket so I could squish it for unleaded, when it was on the road before ( early 90's with good old 4-star ) I ran it with two and to my mind it ran a tad quicker but that could have been just wishful thinking

[wack 63]

Thanks for that,I tried with one gasket and got 1.4 mm squish so that's what i will use.I agree that old 4 star motors seemed to be faster.

[sideout]

I rebuilt my SX150 using 2 head gaskets, as standard over 4500 miles ago. Squish 1.5mm, Jetex 22mm, KBA Clubman. Goes very well as far as I'm concerned even compared with the SX200 that I rode in the late 60s. Holds it's own against standard 200s.

IMHO a very under rated engine.

[scooterslag]

I rebuilt my SX150 using 2 head gaskets, as standard over 4500 miles ago. Squish 1.5mm, Jetex 22mm, KBA Clubman. Goes very well as far as I'm concerned even compared with the SX200 that I rode in the late 60s. Holds it's own against standard 200s.

IMHO a very under rated engine.

Yep have to agree with you there chap- for a standard 150 the Sx lump is a bit of a goer, just in the throws of building up a 175cc lump but might opt for another SX150 spec engine instead though I'm going to bin the gearbox which IMHO slows the bike down and causes it to over rev ( as well as the bloody awful jump between 3rd and 4th)

[sideout]

........... though I'm going to bin the gearbox which IMHO slows the bike down and causes it to over rev ( as well as the bloody awful jump between 3rd and 4th)

What gearbox do you think you'll go for? I'd be interested to hear how it works out.

[bristolmod]

I've used a Vijay Super (NOT the Mk 2!!) with a 16T front on a standard SX150.

Great little box without the large 3-4 jump as standard.

Chris

[scooterslag]

........... though I'm going to bin the gearbox which IMHO slows the bike down and causes it to over rev ( as well as the bloody awful jump between 3rd and 4th)

What gearbox do you think you'll go for? I'd be interested to hear how it works out.

I'm going for a early LI125 box on 47x17 sprockets, might change to 16 if its too flat.