Just Blew A (Machining Plug?) on my Carb... (1 Viewer)

[emtee]

Hey All,

I did a search on this particular problem, but couldn't find anything...

Coming home from work today, got a whiff of fuel, which got progressively worse in a very short period of time. Pulled into the driveway with both windows down and eyes watering. Traced a massive fuel leak to the carb; specifically what appears to be a (lack of) machining plug located in the bottom of the pump housing. With the engine running, fuel POURS out of this port onto my header. Wherever that plug went, it's gone. Aside from the obvious fuel economy issue, there's the small problem of catastrophic engine fire, etc.

I'm guessing I can pop the carb off, thread that hole and seal it up with a machine screw, but am wondering if there's a downside to that. (Downside being anything worse than having to walk the nine miles to work tomorrow morning.)

I have a couple of old (inop) carbs I could probably rob a plug from, but I'm guessing these are one-time-use-only type items?

Any realtime suggestions/options/opinions much appreciated!

Thanks,

 

[chewy]

Sand it to clean it a little and throw some JB Weld on it. It'll be fine by morning. Matt

 

[emtee]

Well, that sounds more attractive than taking the whole maryann off to tap that hole...think I'll give that a shot; thanks Matt!

 

[65swb45]

I've never seen one of those blow off a carb before, and I've seen a carb or two before! Chances are the plug was tampered with.

In any event, I personally have not great luck with epoxy-based solutions to fuel leakage. I would tap that hole and put a machine screw in it. And of course tapping means removing the carb so you can blow the tap shavings OUT of the carb.

Best

Mark A.

 

[grant5127]

I had a similar problem on a different plug tho.. I whittled down the lead potation of a 22 cal. rimfire round and drove it in.. no leaks to this day...

 

[honk]

I had a similar problem on a different plug tho.. I whittled down the lead potation of a 22 cal. rimfire round and drove it in.. no leaks to this day...

"potation" ??

Yeah, a lead plug will have a better chance of staying put than a glue plug will, IMO.

 

[Degnol]

I had a similar problem on a different plug tho.. I whittled down the lead potation of a 22 cal. rimfire round and drove it in.. no leaks to this day...

"Improvise! Improvise, young man!....We won two World Wars that way!"


Honk:

Potation is an Idaho word. I never made it past the 21st grade and even I know that.

 

[emtee]

Thanks for the input, guys!

I tried the .22 rimfire round trick, but when I went to tap it in with a hammer, the damned thing went off and started a fire!

Actually, I went the JB Weld route; I prefer mechanical (threaded) fixes over glue/epoxy, but time was of the essence, and I'm not sure the taps I have would have been sufficient for the job. The port looked to be a little less than 5mm in depth before you get into the "chamber" below the pump plunger. By the time my 4mm tap got a bite into the metal, the tip would have been well into the chamber, and I didn't want to take a chance on fouling the seat for that ball bearing.

So I popped the air horn off, cleaned everything as best I could, dabbed in some epoxy, made sure it hadn't goobered into the pump chamber and left it open overnight to cure.

(Note: when blowing out the various holes/ports in a partially disassembled carb, it's important to remember that just about all of those little holes are connected somehow. When I put compressed air to the plunger port, the little cap/spring/bearing assembly right next to the slow jet shot out of there at roughly twice the speed of my ability to track a flying object...that was a fun 20 minutes on my hands and knees under the rig )

Anyway, got up early this morning, reassembled everything, crossed my fingers and fired it up. No leaks, and the drive to work was fume-free. Even got to work on time; life is good! Well...better, anyway. I'll keep my eye on the fix 'til I'm satisfied it "took".

Thanks again y'all!