Mac 550 carb

[Jasonrkba]

I've been beating up Google trying to find a parts list for the HL63G. Any help from you guys would be appreciated.

Thanks. Jason.

 

[heimannm]

This should help. Let me know what parts you are looking for in particular, I may have something.

Mark

 

[Jasonrkba]

Thanks mark thats exactly what I was searching for. Someone removed the choke and its components. I did get it to hold pressure somewhat but it still bleeds down. I need to replace the needle and seat.

 

[heimannm]

If you've never worked on an HL before, the seat is actually a small, replaceable rubber piece in the bottom of the brass fitting. It does require a thin wall 5/16 socket to remove the seat and there is a small copper washer down in there as well so proceed with caution. Most of the time the only issue is the rubber seat itself has either deteriorated or has taken a "set" from contact with the needle over a long period. The needle and seat kits normally include the washer, seat, needle, and the brass fitting.

The same rubber seat is used on the Walbro MAC carburetors with a primer and has the part number 59480, I have not found a Tillotson part number for the rubber seat itself. Item #9 in the illustration below is the rubber seat.





Mark

 

[Jasonrkba]

I had it apart and the rubber was in decent shape. What I fount was the bolt on top for the cover has been helicoiled. It was leaking pretty bad so I replaced the copper sealing washer with two new copper washers. That sealed it up but I feel some air coming from the throat. The gasket and diaghram from an rk88 fit but the needle and seat/nozzle where different.