The Hodaka Club Forum

So I bought 2 new petcocks for my 1973 wombat from strictly hodaka. The new and improved ones.I took the old ones out & tried to screw the new ones in and I can't get them to thread into the tank. The old ones thread right in and out & don't look cross threaded.The threads on the new ones look the same as the old ones,but I just can't get the new ones to start threading into the tank.any advice ? Thinking about putting the new ones in the freezer and trying to thread them in them. Also the fuel line sold with the petcocks is a b*tch to try and get fitted to the fuel spigots. Ideas ??

The threads may be a bit more crisp on the potmetal petcocks, but the threads are the same. I've replaced all of my brass petcocks with the new and improved models from SH. I found it helpful to "screw in" a wire brush (like a bottle brush) to give the threads on the tank bosses a light dressing. Flush the tank afterwards. Freezing the petcocks may help. Gently warming the fuel lines (I used a very light tough with a heat gun) makes them more pliable and easier to install. Safety wire them for security - not too tightly. Always use an in-line furl filter between the "Y" connector and the carburetor inlet.

Hi Mark,
I run the correct die over every petcock that leaves my shop. When they are made by the manufacture sometimes there is a burr on the threads and over years of selling these I make sure to chase the threads every time one leaves with a German made die.
I promise the threads on the petcocks we sent to you are correct.

Fuel line- push the ends of needle nose pliers into the fuel line open end and open the pliers to spread the fuel line open.

Paul

Thanks Paul, I will try again today . The threads on the petcocks look fine,they just seem to not want to start.Should there be a gasket for where the petcock base meets the tank outlet. On my old ones I used some red silicone to help seal the mating surfaces.

Hi Mark yes there are red fiber washers used to seat the petcocks against the bottom of the tank. # 909017 .
Maybe try a little light grease on the threads of the petcocks when screwing into the tank.
Thanks
Paul

Hi Paul I actually wave a box of assorted red fiber washers. I'll look thru it & find a few.

So I got side tracked for a while on the petcock problem.I tried freezing the petcocks & heating the tank in the hot sun. Still don't fit. I got out my digital caliper & checked the diameter of the threads old verses the new petcocks. Old petcock thread diameter is 9.45 mm diameter.New petcock thread diameter is 9.80 mm.I called Hodaka parts yesterday & discussed the problem with Terry. I sent the old and new petcocks to him yesterday so he could see what I am talking about.I hope he can figure out what the problem is

Mark, I was just in the process of changing out the original brass petcocks on my Ace 90 with the updated pot metal ones and has the same problem. According to Dale Dvorak, the correct die for chasing the threads is designated BSPP (British standard pipe - parallel) size 1/8 - 28. I got the proper die and chased the threads. They installed effortlessly after that. Mine were as you described - too large. I wonder if we got them from the same lot.

Matt, They probably came from the same lot I would think. Glad you got yours figured out. If Terry can't help me maybe I could send mine to you & have you chase the threads.

Absolutely Mark! I'd be happy to - anytime!

I got a call from Terry last night & he confirmed that the petcocks don't fit. He also said that a small batch of reproduction petcocks were not correct as far as the threaded part goes.He is sending me the correct ones & not even charging me shipping for something that is really not his problem.Now that's what I call going the extra mile.Thank you Hodaka Parts Inc for the great service.

That is really excellent customer service. Glad you have the situation in hand.