Author Topic: Another wet airhorn gasket thread...  (Read 1047 times)

Offline fussfeld

  • Garage guy
  • **
  • Posts: 39
Re: Another wet airhorn gasket thread...
« Reply #15 on: May 04, 2021, 06:00:36 PM »
If you need to do anything at all for poor fitting components 99 percent of the time all that is needed is to remove a small amount of material from the corners where the long bolts go thru.  Done correctly it will be just a tad flatter than the main casting under it and re-conform nicely when you tighten things back down.

I have the fixture to flatten airhorns and unwarp castings but rarely use it.  I've found it much less intrusive and no risk of cracking either part using the method described above.

I work on a LOT of very valuable and difficult if not near impossible to replace carburetors.  The best method is always the least intrusive with lowest risk of breaking something.  A 30 ton press and heating up 50 year old metal castings doesn't fall into that deal.

I stock a really nice .015" thicker gasket for the early carbs that is made of an excellent material, and it seals them up most of the time without doing anything at all to either part. 

The good thicker gaskets for the later 4 MAB models were unavailable for quite a while, but I just got some of those in about a week ago. 

Most of the later variety thicker gaskets will wick as the material isn't that great.  I have a lot of them here, but in almost all cases I'm going to make the parts fit better and use the stock high density gasket for those units.

As far as the N/S assembly you should be using a SOLID seat with a .135" hole in it.  They flow equally as well as a windowed seat and will NOT allow the carb to drain back nearly as far after shut down IF you are using the clip on the needle in the first place.

I have found ZERO negatives anyplace using the larger late style solid N/S assembly in any application.

Currently available rebuild kits are showing up mostly with .110" thru .125".  Some are solid but most are windowed.  Occasionally I'll see a .130" seat in a kit or in a carb sent here that was just "rebuilt", but in most cases it will be smaller.

Kind of interesting but at least 80 percent of the time one of the complaints about the "new" build and why it was sent here was LOOSING power at higher RPM's, and guess what?  Without exception every time that complaint was on the list the carb had a small N/S assembly in it.......FWIW.

Anyhow, as a reminder to anyone reading this thread I sell COMPLETE rebuild kits, the most complete in this industry for $45.95.  I will also put together "custom" rebuild kits with tuning parts for any application so it's basically just "plug and play" for the builder/owner.

It will include a high flow N/S assembly and complete accl pump assembly with a lifetime warranty.  The accl pump comes with new spring, stainless return and chrome vanadium spring wire upper for improved performance.  There is a garter spring under the seal to keep it in constant contact with the pump bore and a retainer to keep the pump from pulling apart.  It is currently the very best accl pump available for these carburetors and dating back almost 20 years now ZERO failures and never had to replace one.  IF you want a larger .140", .145" or .149" N/S assembly and/or an HP accl pump just ask and I'll upgrade those parts at no additional cost.


But wouldn't a larger N/S---for example .135" vs .125" make it riskier to flood?    Or is this just a function of float level and/or fuel pressure?

Offline Cliff Ruggles

  • Administrator
  • Qjet Hero
  • *****
  • Posts: 4796
Re: Another wet airhorn gasket thread...
« Reply #16 on: May 05, 2021, 02:06:00 AM »
A later model carb with the small float and .145" seat will EASILY take 7-8psi fuel pressure without any issues anyplace.  I've been running 7.5 psi on my 1977 Pontiac carb now for close to 20 years without the first issue anyplace, float is set at 9/32".  I can crank my regulator up past 12psi and it doesn't flood or even act like it's going to.......