385xp

[Bobby Forrest]

So I have a 385xp. Everything was great with it till the family ran it with low oil in the gas. Melted part of the piston and scracked the cylinder wall fairly well.
So while it's down, I plan on playing a little. Everything I have read says I can get a 390xp piston and cylinder. I'm studying to do a mild port job and a muffler mod. What can be don't to the carb? Carb swap, polish the inside for better air flow.... would the timing need advancing? Anything else to do? Increase spark?

 

[werewolf]

if your going with a mild port or woods style porting, I'd recommend opening the muffler a little, removing the cylinder base gasket, and adj the carb a little richer, carbs are usually best to not modify, fine line on Venturi size on a single cylinder engine, too large and you lose torque. I usually don't change my port timing even with losing the cylinder gasket, may move your max hp a little lower in rpm's, my modded 372 is strongest at 13000 rpm instead at the common 13500 rpm. Others guys on here better at really tweaking those Huskys.

 

[trappermike]

The 385 has excellent cylinder ports and very good compression. I would bore the carb to 3/4",modify the muffler with another outlet for better flow,and raise the exhaust port 1mm and widen it 1mm each side.I would not lower the cyl. which decreases port timing and power.

 

[Huskybill]

As said above raise the exhaust port, widen it, lower the intake port and widen it. Polish out the roughness in the ports with the sanding drums, then go to #2 red polishing compound, then last I use the seme chrome polish they use on injection die plastic molds. I go until it’s shiny. You can rework the piston too.