Kinda getting to my wits end on these 97s... I have taken them back twice now to get them working right.. At first only one would pump gas, one would flood and run gas out the bottom, and one wouldn't do anything.... Second trip back.. Have most of the major bugs worked out.. But wanted to see if anyone had any quick tips and suggestions on how to fix a few minor problems.. That could I guess happen to any carb.. It is seeping fuel out of the screw that goes through the front and holds the float in.. On two of the three. I know it looks like it is coming from above but I wipe it off and you can watch it slowly come out and wick upwards.. Second leak is the screws that go in the bottom front that cover the jets up.. I tighter the screws just a bit and it helped a little.. Cut the leak in half.. But can't get them any tighter.. Is there maybe a sealant that I could put on the threads of these two places to help seal it up? One last question is how high is the fuel supposed to be in the bowl? Took the top off of one to see how high it was..
Castings suffer from old age in that they get little nicks and dings that go below gasket surfaces, they also warp easily. On the larger gasket surfaces rub the part on a surface plate until the gasket surface is free of defects. If you don't have a surface plate take a piece of glass and lay a sheet of fine grit sandpaper on it then rub the part on the sand paper. Wet-Or-Dry paper works best with a little Varsol for lubricant. On sealing areas where things like jets or screws seat use a wooden dowel rod with some fine valve grinding compound and polish the sealing surface. Where your leak is around the float screw I think your float level is too high. When you tighten steel screws into pot metal don't get aggressive. A few inch pounds of torque is all you need. Like two fingers on a screw driver. One final hint, use the correct size screwdriver.
Uncle Max has plastic washers for the bottom plugs that at least takes care of the standard sweating that comes with the normal fiber washers. Worked for me.
Dry all the fittings/plugs with loctite primer then smear a very light coating of Loctite 572 on the threads,in some cases a small amount of thread tape applied carefully on the threads have worked as well,Cleaning and drying of the threads is the key first though. Don't tighten them to much,you will only end up stripping the threads. This way has worked very well on 94s & 97s,I smear this on the body gaskets also once the faces are cleaned and dried,then wipe off the excess, but theres a lot of ways to kill a cat.
As aggie correctly points out, they suffer all the vulnerabilities of pot metal carburetors in general. I understand the nostalgic appeal of 97's, but you are expecting a lot from 75 year old carbs that likely have been apart and reassembled dozens of times over the decades. A new production unit, while a bit costly when purchasing three at a time, might be worth it by providing fresh castings without all the battle scars, wear and tear., warpage, etc. Ray
For the screws in the top a little Indian Head ( or a reasonable facsimile there of) on the screw threads will help if they are actually wicking up the screw. if they are leaking from gasket itself then as @aaggie mentioned lap it. You may also be suffering from too much fuel, try lowering the float a bit or at least check that it is set correctly. The leaking from the plugs can be helped with the proper washer, either from uncle max or just look around for nylon washers that are a little thicker. I have also used an o ring in place of the washer in a pinch. In the original post I notice that these carbs are going back for repairs, there is a lot to be said for doing it yourself. you will always take more care on something that you own than someone else will.
Thanks for all the info!! I do realize these are old carbs and will take some time to get working properly. It just gets a little frustrating when I sent them to a very reputable shop according to people and when I first received them back and tried them I would say the work was sub par.... After the second time they all work now just the few leaks... With old carbs I'm not going to fault him for that.. But I agree that doing it myself I would have taken better care of some things.. Like removing some unneeded parts instead of leaving them on and just cutting them off with a cut off wheel... The top pate and screws are not leaking ... Which is where I figured I would have trouble if anywhere.. Just the screw that goes in the front for the float.. Which the slot in the screw was mangled already.. I'll try some sealant in it an maybe get a new screw.. The fuel level in the bowl when I take the top plate of is about halfway up on that screw that the float pivots on.. And just a shade over where the slot is where the accelerator pump goes in... Anyone know if that's a bit high? I will try some plastic seals or o-rings on the jet screws.. As for the cost I think if I would have bought a kit with 3-97s intake and fuel block I would have been money ahead.. But I like to think I get get the old stuff to work.. Which lands me in trouble a good bit...
And maybe I misspoke they are not going back for repair again.. I think with the help here we can get these leaks fixed and they should be good enough to run
Uncle Max is the man & resident Stromberg carburetor guru...send him a conversation. HRP http://www.jalopyjournal.com/forum/members/uncle-max.11172/
Get these parts from Uncle Max: - new float hinge pins - hex head jet plugs - plastic washers for the hex plugs Put these in and most of the leaking will be gone. The hex head plugs let you get a wrench on there instead of a screwdriver, which is impossible when it's the second or third carb back on a multi-carb intake. Now don't tighten them to 40 ft/lbs, but you can snug them up nicely.
Alchemy - you're too funny! "Most of the leaking will be gone". However, I know what you mean. Two of the four '94s on my roadster (avatar) have mysterious seepage which leaves a little brown stain on the intake manifold. It is so minor that I've given up chasing it down. It has become part of my clean-up regimen. Exposed engines demand lots of attention to keep them looking nice.
The carbs are so porous, and having the original plating missing seems to allow more seepage on most of them. I think the new Strombergs have a thicker top which will allow a tighter clamp for the top gasket, helping remove some seepage. But the users of original Strombergs will just have to live with seepage. Unless you glue your gaskets, which seems like a bad thing to do on a carburetor, to me.
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