Got started on this a couple days ago and didnt think about taking pics until i made it to this point. Saw came in locked up, which turned out to be a minor problem. The bolt that extends through the case to hold the rubber A/V limit bumper had backed out and gotten jammed in the flywheel. Removed the bolt and all was well but my curiosity got the best of me and i couldnt just leave it at that. Knowing the history/use of this saw(local tree service) and knowing the problems with the divider/intake on these saws we decided to give it a full check over before handing it back over. Piston had a few scratches on the exhaust side and what appeared to be some marks on the intake side of the cylinder wall and of course it failed the pressure/vac test so i decided to pull the cylinder and have a better look at the P&C. Turned out to be a better call than anyone could have imagined, ring was in 2 pieces and stuck in the groove. No major damage/wear to the P&C thankfully. We flushed the case with fresh mix and tried spinning it over, gritty/jerky feeling in the bearings when spinning the crank. Coil and crank seals got pulled and the crank spun over again, same feeling so a quick call to the customer was in order at this point. Explained what was going on and what it needed. Since P&C sets are so cheap for these saws we decided on a complete overhaul. Split the cases and go from there. So that leads us to this point, saw is in pieces, cleaned and ready to start the assembly process.
worked on this saw off and on today between customers. Still waiting on the new fuel tank and fan shroud to show up so there is no rush to get it done. Here is how i do bearings and the crank install. First step is lightly sanding the case halves with a file wrapped in 320 sandpaper. I sand just enough to be sure they are flat and true. After they are smooth and most of the imperfections are gone the case halves go in the oven. I dont think this method takes any longer especially on small cases than a heat gun and i prefer heating the whole case half up versus just localized heating of the bearing pocket. Case half in the oven. 320* or so and pull it out long enough to drop the bearing in then she goes right back in the oven while i grab the crank from the freezer. Crank drops right in. The other half goes in the oven, small cases like this 346 it only takes 3-5 minutes to get the case up to 300*. After the bearing is in the other case it goes back in the oven while i prep the case gasket. Trimming it up in spots and a thin layer of loctite 515 on both sides. Pull the case half out and slide them together....having the bolts and impact gun ready is a good idea, most cases slide right together all but the last 1/8-3/16" and either require a couple taps of a rubber mallet to seat them or use the case bolts to pull it together. If your quick about it the case halves pull together that last little bit with ease, if your slow its a different story and if i am not quick enough i grab the case splitter to push the case half back off for another go around in the oven. A little trick i have learned to help when installing the second half is to hit the crank with brake clean immediately before slapping the case on it....that slight bit of cooling on the crank end really helps them slide together. i used to throw the case half/crank in the freezer but it just takes too long doing it that way so the second case half i heat up a bit hotter than the first one and do the brake clean trick to make it go smoothly.
We now have a bottom end assembled. Next step is center/freeing up the crankshaft. I try to do this as quickly after getting the halves bolted together while there is still as much temperature differential as possible. Usually jsut a few wacks with my fancy, high tech crank centering tool. Better known as a great big brass drift pin that came out of some random equipement axle assembly years ago. It has enough weight to it that i can tap directly on the ends of the crank to center and free it up. Usually a couple light taps is all it takes.
Next up is the P&C. For normal rebuilds i just throw the cylinder and base gasket on and go but this is a arborist that asked if there was anything we could do to wake up the little 346. I am not a porter and dont do much as far as mods go, muffler mods, base gasket deletes, and occasional timing advance is all i do. Porting is a higher pay grade than i have acquired so we are going to stick with the simple/affordable mods on this and i think he will be happy. Lets see what we have to work with....is that an oem 346 cylinder kit? why yes it is.....If you havent been paying attention for the last few months here is the deal....Husky fell and bumped their head, cylinder kits dropped drastically in price and the 346 kits took a pretty healthy price reduction from $250 all the way down to $105 so AM kits for these saws have become obsolete IMHO. No sense spending money on chinese junk when the real deal has become so affordable. First up is checking squish to see if we can even delete the gasket. Couple tips for anyone that hasnt done this before. Rosin core solder is the softest so it gives the most accurate reading. Place the solder directly above the wrist pin and do both sides of the piston at the same time to obtain the most accurate reading and if i roll the engine thru multiple revolutions and i feel the solder is causing a bump when spinning it over i will continue spinning the engine over a few more times to get the solder smashed down to the thinnest that its going to be. If you only roll it over one time the solder may be left thicker than the actual operating clearance resulting in some catastrophic failure. Doing one side at a time allows the piston to rock in the bore and give a less accurate reading. Checking squish 90* from the wrist pin also gives a less than ideal measurement so unless your taking the quish down to the bare minimum or have a popup piston that needs clearance checked all the way around i would avoid checking there. I personally will run down into the .018 area on a small bore stock saw...larger bore i dont go below .020. I warranty my rebuilds for up to 90 days depending what was replaced and guys have pushed the limits and survived but i dont want to be on the hook for a failure trying to get the last little bit of performance out of a stock saw. This saw shows .021 clearance on both sides so we are good to go. IIRC not all 346's will let let you delete the gasket because of squish clearance so checking each individual saw is mandatory.
Here is the engine all together. Last 2 things i had to do to have the engine all together and be ready to play the waiting game is repair/replace the coil wire and do the muffler mod. Replacing the coil wire is a simple straight forward deal. It is threaded into the coil so its just a matter of unthreading it, cut a new piece of wire to match the old one, and thread it back in. Replacing the plug terminal will drive people nuts so here is the easy way. First shove the boot on the wire and take a sharp awl or scribe to pierce the wire for the terminal to poke thru. Then put your terminal end on a spark plug and push the "hook" thru the wire in the hole you made. Slide the boot up and over the end of the plug using the plug as your "handle" to maneuver the terminal into the boot.
Here is the last thing i am able to accomplish until the rest of the parts show up. Muffler mod. These just have an empty can so no need to split them and gut em. The deflector covers the outlet up so its almost impossible to access it and enlarge it so i went the route of making this a daul port muffler. I needed a deflector to cover my new outlet so i went to the press and stamped out a new one. These deflectors come out of the press looking pretty crude but after trimming them up and shaping to match the muffler i am working with they come out looking pretty good. I also insist on running screens in all my saws and anything that i modify so i keep some stainless mesh on hand. Currently the deflector is held on with sheet metal screws but those will be replaced with nutserts later on. I realized i was out of them so i finished it up with what i had on hand.
Nice build and great advice in your posts. Good thinking on cleaning up the gasket surfaces. I use a clean piece of sandpaper taped to glass. Ive cleaned up two sets that had mating issues. Works pretty well.
Ford F-150 great job on this project your step by step is great helpful information thanks for taking the time to explain everything
Had some of the parts show up today that I was missing but still more to come so hopefully next we will be able to finish this up and take it for a spin
Great pictures and a good narration. I really like the help full techniques you have shown. Making the punch and die for a muffler deflector has me thinking also.
I spent about an hour making that one out of scrap steel. It still needs fine tuned and i would like to try a few mods on it but never find the time. They only get used in my shop so nobody sees them till after i have trimmed them up and tweaked them into a nice shape so modifying the die set is pretty low priority. Works good enough the way it is and may even work better if i used some thinner steel but i have a 4x8 sheet of 18ga here so i have never tried anything else.
PM me and I may be able to get you something thinner and harder (or softer so it's easier to work?). Rather discuss in PM.. Maybe a barter? I love to barter. And I've been wanting to make a trip to your shop for awhile now!
