What holds the boosters in place on the nikki?

Mine are loose. Does this cause issues??

Please see video!!!http://www.youtube.com/watch?v=vMCSx...1&feature=plcp

 

Well luckily for me, I have several Nikki carbs laying around. I pulled the booster out of my carb and installed one from a spare. Gave all a couple of taps with a brass hammer and...disco... no loose boosters.

I still wonder if this could have caused any carb issues.

This car has NEVER wanted to run right with an air filter on it. You put an air filter on it, it was down on power in the upper revs. It just would NOT pull.

Take the air filter off, it ran like it should.

This has not really been a problem for 3 years since all I did was autocross.
Now that i am road racing it is more of an issue. I need to keep clean air going into her.

I wonder since this was so loose, if it was causing gross air leakage and not properly delivering fuel??

Maybe the air filter exaserbated the problem??

Any ideas??

 

While I do not have a solution, I admire your dilemma....



Good luck. I'm curious myself now.




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Boosters are only pressed-fit into the carb. One of the reasons why Mazda does not recommend removing them on rebuilds. Only takes a few in/out cycles to make them loose.

Having them loose wouldn't be good, but I've never been down that road so I can only theorize.

Seems like the minimum problems it would cause would be disrupted airflow over the fuel ports, but seeing as the booster bases are also the carriers for the main air bleeds & the passage for main fuel feed, if the base fits too loosely you'd get air &/or fuel bypassing the bleed & feed, and it could play hob with your mix.

I'd be tempted to maybe shim them in with some thin foil (leaving no gap), or at minimum put a light layer of hylomar on the outside of the part before pressing them back in, to prevent any leaks.

 

Yeah Divin, I am kinda thinking it could cause "some" issues. The booster holds the air jet, but you would think you still need a good connection between the booster and the main body. I mean this "seal" or "connection" passes gasoline and air through it!

I was able to change booseters from another carb and give them a "whop" with a brass hammer. They are nice and tight now.

 

I still haven't found a great fix for this yet but the best so far has been wrapping some teflon tape around the bottom of the booster venturi where it presses in. If anyone has better ideas I am all ears (or eyes in the case of the forum).

You definitely want them tight as you will get inconsistent airflow and air leaks in the air bleeds. As Sterling has mentioned and I am seeing, changes in the boosters make a huge difference in the airflow characteristics.

 

Now that I see it is fairly easy to pull them out, I will be doing some booster mods in the future.

I think I read somewhere that Sterling said you get a big bang for the buck pulling out the choke mechanism and cutting off the "bridge" side of the booster and smothing it out (airfoil effect).

 

Sterling tought me howe to deal with loose boosters. Take a center punch that matches the inside of the booster. Wax it up (rub a candle on it). Lightly and I mean VERY lightly tap your center punch in. Test fit it in the carb until it starts to feel snug. Then drive it in. You're done. I repaired a carb with VERY loose boosters. Never had to do it since.

 

Yes and smooth out all of the casting lines. When you cut the bridge make sure to cut it straight up and down.

 

That makes sense; expanding the base portion of the booster. The alloy they're made out of (basically pot metal, aka "cheese") is really soft.

 

Yes this seems like a brilliant idea! I will do that if I run across loose boosters again!

 

I guess I need to go get me a dremel kit. My old one gave it up! I wonder what would be the best tools to cut and then grind and then polish up the boosters??