hi all! i have a holley nh carb that needs rebuilt.any suggestions how to remove the spray nozzle and the needle seat? i have had this carb in penetrating oil for two weeks now and still won't turn out. i don't want to get this carb junked out. thanks . Ken
Best advice on this subject was what I learned here on the forum. Use a torch to heat the casting to a dull red around the area of the stuck parts. Some say to quench it, but I have not been brave enough to do that. After cooling, the spell is broken, and the part will be easy to unscrew.
Heat and cold water are your friends! Get the area of the nozzle very hot, not quite red, then drop it in water. Turn out the nozzle with light finger pressure. Works every time. Takes about 10 minutes. No soaking required.
Ken, your T in the profile pic looks like a perfect hunting rig with a preset blind ready to go.
Erich be brave! It is the difference in the contraction of different metals that breaks the devils hold! Nothing will hurt the cast iron. It is not that fragile.
So far I have not had to, but next time it will be PPPFFFFFSSHHT (sound of casting being quenched) all the way. That would be faster too.
thanks for all the info guys. hunting rig? that is a good idea cuz i like hunting and model t's.
Ken, so do I and I have been waiting for just the right chance to combine the two.
Erich i hope my t looks as good as yours about a year from now. when i get it finished I'll post some pictures
Happy hunting Ken. Between the T and deer and turkey hunting, I am nearly in heaven already. Both are best if shared. Happy T-ing as well. Looking forward to seeing the progress.
Heating cherry red and quinching or just letting it cool on its own always works for me also - Jack Daron recommended that to me a while back and it does work well. I had the exact same situation on the NH carb.
Only time I ever broke a carb casting was after soaking a long time in kroil, twisting with a cheater bar on the tool. The torch is so much better.
To Erich and EVERYONE who chooses the quenching method (the method WE ALWAYS used) pay attention:
HANG THE CARB FROM A WIRE WHEN YOU QUENCH
STEAM is unbelievably hot.......and fast.
I know it's getting late but i just had to give the heat and rapid cool a try. pice of pie! I think a slow cool would work the same. thanks for all your help guys. Ken
I have an NH that I cannot get the main jet loose. Every couple months I heat it with a propane torch and then let it cool and put Knocker Loose on it. Been trying for a couple years now. No joy.
Royce: Propane is not hot enough. Acetylene is needed.
That is true - I kept trying with propane. Then I used the Acetylene, and it worked first try!
Haven't done many, maybe 6 all told (all NH). Propane always worked. No quenching and not red hot either. Right size screw driver is important for both needle seat and jet. Be totally sure to remove the rock hard gaskets from both before re-assembly. Not really sure if it's the threads sticking or both these units being locked onto the gaskets that causes the problem. Their like iron when removed and can easily be missed by a 1st. timer.
For me the propane was not hot enough. If you do not have an oxy/acetaline set up, perhaps a MAPP gas outfit would work.
Craig, excellent point on the steam hazard. No burns = good day.
Charlie, good point on the need to fully remove all old gasket material. It does get petrified in there and looks like part of the casting sometimes.