Easy port work 385xp question

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Stu92

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Hi there, I have a 385xp which is lacking power in a big way, I have a 390 cylinder and piston on the way but before it goes on I'd like to do some easy port work without using a degree wheel, I've never done this before but am really keen to try, thanks
 
Give it the Farmer Jones treatment.

1. Open the muffler outlet and remove the screen.

2. Widen the intake and exhaust ports, but don’t grind on the top or bottom.

3. Set your squish to 0.020-0.025”. You may be able to simply Delete the cylinder gasket. Some saws are too tight with it missing, so a thinner gasket must be made. Most OEM base gaskets are 0.016-.020” thick. A minilla folder is usually 0.010”. The wall of a beer can is usually around 0.005”.

Even to do these simple steps I recommend some research (tons of threads on here and elsewhere), a pair of calipers, 0.032” solder, a dremel and some carbide burrs.

Bear in mind that you’re wanting to go McGiver on you $900 chainsaw. Spending $25 extra on a timing wheel is a good idea. If you don’t have patience and concentration you’re not likely to be happy with the end product. Take your time and your saw will be way better.

Best of luck!
 
Thanks for your reply, I decided to get a wheel to try do everything properly. I'll do more reading before I start so I can hopefully get a good result and not break it.

What would be some good timing numbers to get a powerful saw? It currently has a 28inch bar on and stops constantly when in wood, just doesn't seem to have any power to keep pulling. I'd like to get it to a point where with the whole bar in a log it'll keep going
 
Sounds like something is wrong with your saw. A 385xp should pull 28” 3/8 full chisel through almost any wood. Could be as simple as a clogged muffler screen or as bad as a spun bearings (or cracked case). Don’t run it until you figure out what your problem is. Get it back to a solid running saw before you create exta variables with porting.

Here’s a thread with some good info:
https://www.arboristsite.com/community/threads/making-a-385xp-better.272812/
There are several others out there too.
 
I'm a bit late to the party here, but I took to my roughest 385 about a year ago & got surprisingly good results. Did a gasket delete, took about .015 off the top & sides of the ports & polished them, narrowed the edges of the transfers, matched muffler port & gave the muffler a second outlet about the same size as the original. Squish ended up being about .020 & compression up around 190psi. The result was what is now my favourite saw... Blows away my other 385/390's & holds it's own with my mates stock 660
 

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