2 replies to this topic

[AlexP]

When overhauling my twins hs4's, I noticed that the gaskets between air filter and carb body were installed upside down. This caused the two holes that take air to the suction chamber to be blocked (the holes that look like another set of bolts would go through them).

Now, seeing as this is a hard mistake to make, meaning that it must have been deliberate, why would this be done? I have rectified this 'mistake' but am no worried that it might have been done for a reason.

[Ethel]

The holes, I think you mean, are the communication ports to the underside of the piston. Along with the 2 ports (in the piston by the needle) that communicate the pressure downstream of the jet to the above the piston they are what makes the carb work - essential really.

[AlexP]

Cheers, thanks for that.

Yeah, I thought they would be pretty essential - might be why the mini has been running pretty rough, but It must have been like that for ages (5+ years) before I got the car. I'm looking forward to getting the rebuilt carbs back on and setup on the RR I have booked for next monday to see how much difference it makes.