Hey guys. I'm new here as member. This site always seems to pop up on Google when I'm looking for info on my tree service equipment so I finally joined the community. I'm looking for any info you guys wouldn't mind sharing in getting better performance on my personal husky saws. Those three are the ones I use on the job and they'll still need to be decently reliable. I've always been into 4stroke performance in anything from go karts to 800hp ethanol 4cyl engines. Never had much to do with 2strokes other than a pipe and jet kit on dirtbikes so I'm pretty green in this. I'd love to mod these saws and I have an extra 372 576 and 7 extra 346's for parts. Any info on this would be awesome guys. I really appreciate the help and I'm happy to be a member.
346xp 372xp 576xp
- Thread starter Charles
- Start date
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You may want to post this on the regular chainsaw forum, it gets a lot more traffic. But to answer your question- a muffler mod and then check the squish and delete the base gasket if possible are simple performance upgrades. There are plenty of reputable saw builders on this site you can also send a saw away to and have them give it a big upgrade.
windthrown
361 Junkie
All the saws you have there are the better Husky saws. The 376 is a mean beast, and the right size for just about anything. And it has an inboard clutch... which is my only real complaint about the 346. You can muffler mod them really easy yourself, and even lightly port them yourself with a Dremel tool and some grinding bits. On the Stihl side, I have muffler modded most of my saws, and lightly ported several. Muffler mods usually entail drilling more holes in the mufflers in the right places, or changing muffler parts to add more holes. You can do a search on this site and review the mods on all the saws you have listed. Each one has their own recipes for modding and porting. Porting has many levels, and there are various recipes for porting. It also depends on what you are using your saws for. Generally work saw modifications have lighter porting and race saw mods are more radical and designed for running for shorter durations.
You can easily open up the muffler and do a light port by slightly lowering the cylinder height and widening the exhaust ports. Retune the carb after doing that and you can get significant gains. There are two basic methods to more radically port a saw after that. At a certain point of lowering the cylinder height the piston will slap the cylinder at TDC. To compensate for that, you can either cut a ring around the outer top of the piston and make it into what is called a 'pop-up' piston. Or you can mill an area from the top of the cylinder which is commonly called a 'cut squish band'. After that, both methods involve cutting the base of the cylinder, and both methods will increase the compression, as well as change the timing of the ports. Changing the port timing often times creates a saw that runs worse than stock though (depends highly on the saw design) because of the drop in the entire cylinder (including the ports) compared to the stroke of the piston. So to account for that, the ports may need to be modified. Depending on the saw, you may need to raise, lower or widen the intake, exhaust, piston, and transfer ports. This involves port timing, and gets rather involved. There are many threads on port timing on this site. You can also advance the ignition timing, re-jet the carbs or change to larger carbs and boots, as well as do some other things to get more power out of a 2-stroke.
You can easily open up the muffler and do a light port by slightly lowering the cylinder height and widening the exhaust ports. Retune the carb after doing that and you can get significant gains. There are two basic methods to more radically port a saw after that. At a certain point of lowering the cylinder height the piston will slap the cylinder at TDC. To compensate for that, you can either cut a ring around the outer top of the piston and make it into what is called a 'pop-up' piston. Or you can mill an area from the top of the cylinder which is commonly called a 'cut squish band'. After that, both methods involve cutting the base of the cylinder, and both methods will increase the compression, as well as change the timing of the ports. Changing the port timing often times creates a saw that runs worse than stock though (depends highly on the saw design) because of the drop in the entire cylinder (including the ports) compared to the stroke of the piston. So to account for that, the ports may need to be modified. Depending on the saw, you may need to raise, lower or widen the intake, exhaust, piston, and transfer ports. This involves port timing, and gets rather involved. There are many threads on port timing on this site. You can also advance the ignition timing, re-jet the carbs or change to larger carbs and boots, as well as do some other things to get more power out of a 2-stroke.
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Wow lots of info. Thanks again. I'm really having trouble finding a proven template or design for exhaust and mild portwork. I have a larger bore carb I believe I can tig an adapter together for the 346 to aid the porting and piping. Just a little scared to get too crazy with the port timing. I understand widening the ports to increase flow without messing up the timing and its a plus that I have so many of them to learn with. They are all runners that have been dropped or ran over or something else stupid and they're too expensive to replace tanks and handles to repair them so I just keep em for parts. The 372 is the one is really like to make a beast.
The 576's both have low hours and have both leaned out and burned out piston and cylinder on exhaust side. Both of them only running husky parts and local dealer is confused so I'm still scared of them. One ran 25 minutes after rebuild and the other ran about a week. I wouldn't mind playing with aftermarket parts with them because I can't keep building them and sending them out with my guys only to be let down. To be honest I was really disappointed with husky over the 576xp. Less than a year running with a total of 3 piston cylinder kits bought and they only get ran to drop and cut the log. Probably a total of 40 hours each of runtime. Thats running husky brand oil at 40-1. Both of the 372's I have are probably over 10 years old and only one has shut down on me.
The 576's both have low hours and have both leaned out and burned out piston and cylinder on exhaust side. Both of them only running husky parts and local dealer is confused so I'm still scared of them. One ran 25 minutes after rebuild and the other ran about a week. I wouldn't mind playing with aftermarket parts with them because I can't keep building them and sending them out with my guys only to be let down. To be honest I was really disappointed with husky over the 576xp. Less than a year running with a total of 3 piston cylinder kits bought and they only get ran to drop and cut the log. Probably a total of 40 hours each of runtime. Thats running husky brand oil at 40-1. Both of the 372's I have are probably over 10 years old and only one has shut down on me.
There's something going on with the 576s. The 372 with a little machine work can be made a lot stronger. The 576 sounds like it needs a whole fuel system fixed or new seals. It shouldn't toast a piston in that short of time.
Yeah we pressure tested the crankcase and the crank seals were good and on all three rebuilds the carb was adjusted a little rich actually so we thought that would take care of it but both of them still failed. They are both early models and husky tech said sorry about your luck so they've just been sitting in the shop.
HuskStihl
Chairin'em for the sound
There are lots of nice step by step porting threads, sometimes including timing and duration numbers. My 385 became a whole new animal with a muffler mod, replacing the base gasket with yamabond4 and "polishing" the existing intake and exhaust ports. Nice to have some "extra" saws to play with. Welcome aboard!
windthrown
361 Junkie
I dunno how thick the base gasket is on the Husky saws, or how well they will take to a base gasket removal. I have only ported Stihl saws. You would have to check the squish. I would imagine that you would have to correct for port timing changes.
Yamabond4 is like Form-a-Gasket. It is a goop in a tube that you can make thin gaskets with to fill the gaps and seal the base of the cylinder to the case. I do not like removing the base gaskets, but a lot of people do that.
Yamabond4 is like Form-a-Gasket. It is a goop in a tube that you can make thin gaskets with to fill the gaps and seal the base of the cylinder to the case. I do not like removing the base gaskets, but a lot of people do that.
