Simple Question: hopefully!

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Cyrus6151984

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Have a JonnyRed 2255, can it have a little more life breathed into it doing a big bore kit using a 455 jug and piston? What else other than gaskets and re-jetting with the possibility of removing the muffler screen could be done? She is a great saw, but we dont have a SAW shop within 3 to 500 miles of me and the guy the does my 2stroke porting ain't never looked with saws?

Any and all help would and will be appreciated! I'm new on here but couldnt find the answers anywhere?

Also! Is it possible to swap gears at the clutch to change chain speed? I couldnt find anything but OEM replacement stuff

Thanks again, ready for whatever roasting comes my way and I hope I posted this in the right area! I do look forward to any knowledge I can gain from you guys tho!
 
Welcome!

The 2255 is not a saw I’m personally familiar with, but I’ll try to help.

Jred 2255, Husky 455, basically the same saw. The cylinder and piston are identical, so no gains will be had there. It’s possible you could fit a 460 block onto the smaller frame, but I don’t think so.

But there are several standard tricks to wake your saw up that are worth considering. Each has a varying degree of effectiveness relative to the model.

Muffler Mod:
Your muffler has a screened outlet. Modern saws commonly have a very small one and many have additional baffles inside. It’s common practice to add additional exit ports to the muffler and remove internals that inhibit the rapid exit of exhaust gasses. A general rule of thumb is that the exit size of the muffler should be 80% to 120% the size of the exhaust port coming out of the cylinder. Starting small is the wise approach. Many people abandon the spark screen entirely, but I recommend screened outlets for a work saw.
Muffler Mods have some down sides. They make your saw a lot louder. They can increase fuel consumption. And they can allow foriegn material back into the cylinder if done incorrectly. They’re still usually the easiest way to get a quick power bump out of your saw.

Ignition Timing Advance:
Behind the pull start of your saw you will find the flywheel. It has a very specific relationship to the coil mounted beside it. In tandem they cause the spark plug to fire at a specific point in the piston travel cycle. It’s a relatively easy process to remove the flywheel, slightly modify the keyway that sets the flywheel position, and then reinstall. This causes the spark to happen slightly sooner, which can positively affect RPM and fuel burn efficiency.
The issues with this are that it may not improve your saw, it can be difficult to determine how much to modify the keyway, and you have to remove the flywheel. Although still a very easy performance gain, it requires some understanding of how to disassemble the saw and some research relative to your model and where the benefits will be found.

Bigger Carburetor:
Many saws can be fitted with a carb that has a larger bore and/or jetting. This can allow the cylinder to take a bigger gulp of fuel and air. I actually think your saw may be a good candidate for this as there are several larger carburetors built in the same configuration as yours.
The down sides to this are many. Often a larger carb will overwhelm a cylinder not modified to work with it. Although the saw may do well at a specific range of throttle, the bigger carb may be much harder to tune for general performance. Hard starting, poor idle, weird throttle response and general finickyness are common issues. Fitment into the saw can also be a big issue when bumping to a bigger carb. They take up more room, may not connect properly, and can have travel issues with moving parts.

Cylinder Porting:
Probably more than you want to take on. The cylinder is modified by grinding away material in specific areas. Tons of room for error and it’s a lengthy process involving major disassembly of the saw. Also, your saw is a clamshell strato, which is one of the hardest to see gains that warrant the time and effort. BUT, porting would be the most comprehensive approach. It would include all the stuff mentioned above and fully change the character of the saw.

You’re going to need to keep digging information. @Terry Syd has done a lot of cool work with modding a 450 (the orange little brother of your saw) and probably has the most posted information that would help you. Simply searching “455 muffler mod” or “455 timing advance” will get you started. Definitely look on YouTube and other sites. There is a lot of information out there to piece this one together. You may even find step by step instructions.

I almost forgot about your chain sprocket question.
Your saw delivers a certain amount of Torque to the sprocket. The bigger and longer the chain, the harder the saw will have to work to drag through the wood. If you increase the diameter of the sprocket you’re raising the gear ratio and creating even more work for the saw. It’s a trick used in large saw with small bars to cut through undersized wood. It’s a race trick. For a smaller cc work saw it will make the chain run faster until you put it wood, then the saw will bog to a lower cutting rpm. The exception is if you’re only cutting undersized wood. Your saw with an 8 or 9 pin sprocket will struggle to drop an 18” tree, but would probably sing the through the smaller limbing cuts. In short, unless you’re only using your saw for limbing, adding a bigger sprocket is a bad idea.

I hope that’s helpful. There is a wealth of knowledge here and hopefully some others will chime in. I encourage you to spend some time reading and then go for it! Modding saws is super fun.
 
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