Herko Block

[Deye76]

Guys who use Herko blocks to tune, anyone have the plugs/rivets leak, causing decel popping?

[remington007]

I use the Technoresearch set up, if the nut-serts are properly installed and block off screws and seal washers installed tight i have never had a leak. Now removing the seal screws after years of use is another story.

[rigidthumper]

If you have a loose/leaking unit, replacement 3/8-16 SS Rivnuts are $9.99 for a 10 pack on Amazon.

[Coyote]

If they the rivnuts weren't installed right they can come loose. I've replaced a few.. just drill them out and pop in a new one but you'll need a tool to install them.

[Deye76]

All good info, many thanks.

[Coyote]

If you just need a couple of new rivnuts, I can send you a couple. Just PM me an address if that helps.

[Deye76]

Very generous Coyote.  If I can determine they are leaking I will take you up on the offer. Not sure how to test them for leaks, thinking soap water will evaporate to fast.  Many Thanks.

[kd]

Carbon tracking (collected with a paper towel) would be a dead giveaway so I suspect that isn't occurring.  How about smoke?  You can check the gaskets at the head at the same time.