HSC32 Hitachi Carb - Float Bowl Drain screws

Hello everyone,

These are off a 1982 Yamaha Seca 650.

I've got my carbs apart and I am finding the float bowl drain screws have been terribly mangled by previous owners / mechanics. I soaked the screws in WD-40 - no budging.
I'm looking for ideas to try before I use an extraction bit because these screws are not manufactured any more and there are no supply houses that carry them. I cannot afford to purchase all new carbs.
I know placing these in a vise would be a bad idea - cracking wise. So can anyone offer some suggestions about what I ought to do?
Thank you for your time.
Spencer

 

Sure you can get new ones, in many styles.

email: info "at" xj4ever "dot" com

 

screw them to a 2X4 and put that in your vice. heat is your friend, lots of it. a propane torch can't melt aluminum.
50/50 automatic transmission fluid/lacquer thinner or Kroil. wd40 is for removing price stickers

 

Polock hit this one right on the head, when the Aluminum expands from heating, the screw should be loose. If it's still stubborn, tap the bowl gently with a hammer. If you still can't get a bite on the screw, it's drill and easy out time.

 

Thanks. This is why I spend time in forums because lots of different experience by knowledgable people helps me a lot.
An add on question. What if anything do I use to lubricate those threads upon return to the float bowls?
Are the threads on drain plugs the same regardless of model hitachi carb?

 

Hitachi drain screws

i bought a set from this guy couple years back. they work great and I suggest the same to you. plus the price for a set from him is cheap! he's not out to screw anyone. just send him an email & he'll mail them for a couple bucks extra.

 

As above, various styles of replacements are available. Use a small dab of anti-sieze compound on reassembly.

 

Webby, I would recommend anti-seize compound and tighten just enough to stop the flow of gas the just one more tweak to make sure it doesn't loosen.

 

I'll pitch in another vote for Aero-Kroil. You'll have to order it online, but it's worth the wait - Trust me (and everyone else on the site who's used it).

Kroil takes time to work. Spraying, waiting a day, spraying again, etc and it will work it's way into the threads by capillary action.

Those don't look too terribly mangled. Something I did on a carb rack screw that I mangled: I couldn't get an impact tool (cheap ones you hit with a hammer) to bite after mangling. I took the cross bit out of the tool (hard steel), put it in the screw head, and rapped on it a couple of times with a hammer. That made enough of a cross indent for the impact tool to work. All this, of course, after the kroil. The hard part there is mounting the float bowl in a vice, supporting it, and orienting it so that the impact won't damage anything (or send the bowl flying across the room).

 

So I heated up the float bowl area where the plugs are and was able to get the screws out - thanks a lot for that idea.
I've purchased replacement screws from Steve. So now I get to contruct a fuel level indicator.
Though I was stymied a bit by the screws, this process hasn't been so bad actually. I'm guessing it will be more difficult getting it back on the bike.

 

IMHO, disassembly is the WORST part of the carb rebuild the first time. Removing stuck screws, breaking easyouts in the carb body, or breaking float pillers, or drilling things out, can result in a lot of heartache.

Besides that, removing the rack, disassembly, reassembly, and reinstallation is just a matter of organization and patience. Get new airbox boots, or boil the ones you have to make them more pliable (I haven't done it, but people on here have recommended it, search for it), that'll make it easier to reinstall the rack.

 

You don't actually have to boil the boots themselves.

Boil water in a pan.
Remove from heat.
Wait 5 minutes.
Add carb boots to water.
Wait ten minutes.
Remove boots and slide on.

 

Thanks guys. I'm itching to get riding - that is for sure. I have learned a lot about what's inside a carb. I will work on the understanding how it all goes together from other forum posts.