QD 10HP carb rebuild-needle packing, etc

[motordummy]

todays winter project on motor rebuild is the carb. got it apart and soaking. a couple of questions. i am using an omc/bombardier kit 439071.<br />1. welch plug over slow speed jets. two plugs came in the kit but the only one i can find is over where slow speed jets would be. second an extra? second, how do you get the old one out and the new one in???<br />2. there is a thick-donut like o-ring with the kit-no clue what it is. it is not the gasket that goes over the bottom of the jet where the float bowl is. there is also a small cotter pin?<br />3. in what looks to be all of the needle packing stuff there are 6 fiber/cork washers, 2 plastic/nylon washers, and 1 red (rubber?) washer. are these all for needle packing? how many fiber/cork or nylon or red ones to use and in what order?<br />4. how do you get the old packing out? i am hoping the soak will just eat away the old crap and using a nail and scraping. Thanks.

 

[Xcusme]

Re: QD 10HP carb rebuild-needle packing, etc

You're right about question #1 , it's an extra welch plug. These kits sometimes contain parts for slightly different models of the carb. Match up and replace the parts that were in your carb when you took it apart. Be sure you replace the gasket on the lower end of the high speed jet tube. This gasket seals the lower carb body to the high speed jet. If this junction leaks, you will have a very hard time getting the motor to idle smoothly.<br /><br />Remove the idle adjustment needle valves. Remove the stem packings. Cleaning fluid will not dissolve these packings. Upon re-assembly, put in 3 fiber stem packings, followed by a nylon packing washer. Replace the packing nut. Some carbs use the red rubber stem packing seal and not a packing nut. Again , use the parts from the kit that match your old parts.<br /><br />The welch plug can be removed in one of two ways. Use a sharp awl or ice pick to punch a hole in the center, and pry out. You can drill a small hole in it and then using a sharply pointed pick , pry it out. If you do decide to drill the plug, be very careful not to allow the drill to go too deep. Drill just thru the plug, the chamber underneath the plug is pretty shallow.

 

[motordummy]

Re: QD 10HP carb rebuild-needle packing, etc

is scraping out these old stem packings easiest way to get old ones out? they are really caked in there.

 

[Xcusme]

Re: QD 10HP carb rebuild-needle packing, etc

Since the packing washers are fiber based, use a dental pick or heavy needle to pry them out. Try to avoid dropping small bits of the packing down into the opening for the needle valve screws. Since you plan on removing the Welsh plugs anyway, you can use compressed air to blow out the passages after soaking. To replace the Welsh plug, install the new plug with the crown of the plug up. Using a flat faced punch, seat the Welsh plug. By flattening the crown, the outer diameter of the plug will effect the seal.

 

[R.Johnson]

Re: QD 10HP carb rebuild-needle packing, etc

As you have found out, that packing can really be stuck. Here is the way I deal with it. Get a 7/16-20 tap, grind the entire nose of so that it looks like a bottoming tap With no starting threads. This will clean the hole out right to the bottom of the threads. Do this with the top welsh plug out so you can reverse blow ot the remaining crumbs.