Carb Rebuild on a ’58 7.5 Johnson

[cron78]

Using the Sierra carb kit (18-7043) and the packing washers for the high and low speed needles are a hair too wide to fit easily into the threaded holes they should fit into that house the needles. Is that normal? Is it a problem? Should I hold out and order OMC carb kit that might be a little better quality and have packing washers that fit better? Do I force them down into the hole (I’m worried that they will tear off bits against the threads that can cause problems in the carb later.

What have you guys done when encountering this issue?

Thanks,

Dale

[billy-t]

I find the Omc kits work really well.

[wedgie]

I soak them in 2 stroke oil for a while and then gently poke them into the "holes" with a blunt end of a dental pic. Then wind the needles through. They will take on a conical shape when you tighten up the packing nut and that should decrease the outside diameter a bit. Others may do it differently .

[cron78]

Thanks for the replies.

I haven’t rebuilt a carb since my old ’75 Scirocco carb circa 1980. I suspected that perhaps they needed to be wet with something. They are hard and fragile. I split one just pulling it out of the hole after just pushing it in flush with the edge. Luckily there are a couple extra in the kit. I’ll give the two cycle soak a try.

The old ones I pulled out for the rebuild just crumbled away. I guess they are akin to the old oakum packing in ship timbers.

Already ordered an official OMC/BRP kit for next time.

[chris-p]

I use a lot of the Sierra washers, they are supposed to be a touch big, as are the OEM ones.

Just drop in hole, and use a blunt object, or large flat screwdriver to push them down to the bottom.

[frankr]

Start the packing on the needle, then screw the needle in till gently seated and back off correct # of turns. Now use the packing nut to shove the packing in the hole. The needle being in place prevents any shreds from entering the interior of the carburetor.

The originals were stampings from gasket material. Back in those days, OMC gaskets had asbestos in them. That is why the packings seem slightly fiberous. Today’s packings are inferior to the old originals, but what ya gonna do?

[Author]

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