Chainsaw Repair

Husqvarna - Stihl - Poulan - Jonsered - Dolmar chainsaws and more => Echo => Topic started by: mbrogz3000 on September 13, 2013, 05:32:52 pm

Title: CS-600P w/ HDA-203 and CS-8000 carb nuts & bolts (pics inside)
Post by: mbrogz3000 on September 13, 2013, 05:32:52 pm
This is just a quick post to show Sharkey's carburetor mod for the Echo CS-600P, in case the stock HDA-268 gets clogged and cannot be cleared/cleaned AND if the carb mounting threading in the rear handle assembly become stripped out.  Big thanks to Sharkey for his advice on what parts to buy and how to go about the fix!!

My CS-600P, which sees only occasional but demanding use when called upon, basically refused to start. After proper diagnosing (spark, fuel and impulse lines were good, intake tube was good, no piston scoring, and good compression), I concluded that there was an issue with the carburetor. I tried a rebuild kit, and that did not work as the carb still was refusing to pump fuel. At the point of reassembling the carb to the saw, I realized that one of the screws was severely loose to the point of barely catching any threads...as this was probably an air leak that had been there for a while. Anyway the engine still would not burp at all.  After checking for replacement parts from the major online parts places, I became shocked at how expensive the damn HDA-268 costs, at roughly $100+ with shipping. The gas tank rear-handle assembly would fix the stripped mounting hole problem, but was annoyingly $65.  I scoured the net for an alternatives or folks with the same issue, and stumbled across the site here. I read through Sharkey's guide (and learned that the jet is semi-fixed, meaning fixed), asked him some questions, and bought an HDA-203 ($47) + the CS-8000 carb nuts/bolts ($8-$10). The new carb worked immediately, and brought the saw back to life after tuning the carb. I was really happy at that point. However the performance was still the same as before...with the saw once warmed up and after getting through a heavy cut the saw would momentarily go into a lower idle than normal then rebound. It would never sound right doing that. Today I finally got around to installing the CS-8000 nuts and bolts, then retuning.. pics are below and I can attest that this combination of parts fixes the air leak problem.  Reason I didn't partake the warranty was because it was purchased at Home Depot 20 months ago as a refurbed saw for $380, real Echo dealer's were far away from my house, and I didn't want to deal with convincing them to honor the warranty. Plus I wanted to learn more about small engine repair.  Its really strange that the carb died, as this saw has got some real good use and drank many many tank fulls of gas... and has never been stored with gas in the gas tank.  Only thing I never used to do, but have now learned, is to run the carburetor dry after emptying the gasoline out of the tank.

As I had the saw apart, I couldn't believe how much mechanical engineering detail went into this saw, as well as the quality of the build. This saw is like the Apple of chainsaws! The only thing I can think of is that Echo purposely decided to select a carb design without replaceable/removable fuel jets + intentionally using aggressively threaded screws into plastic to secure the carb to the intake port, which eventually would warp the holes or become stripped during a semi-advanced cleaning. Maybe its meant to go bad after a year of use by you guys who use it every day or immediately after the year 5 warranty during homeowner use which sits in a garage 99% of the lifetime. This drives parts sales, or otherwise leads to the purchase of a new saw.  Anyway, below are pics of the fix..  This cost me roughly $60 between a new HDA-203, and CS-8000 carb nuts/bolts. 

Title: Re: CS-600P w/ HDA-203 and CS-8000 carb bolts (pics inside)
Post by: mbrogz3000 on September 13, 2013, 05:33:19 pm
This mod/repair assumes you know how to disassemble and more importantly reassemble the major assemblies of a chainsaw. The rear handle assembly has been removed to perform the mod.

First three pics. I stepped the holes up to I believe 1/4". Be sure to double check.  Start with a drill bit the size of the existing hole, then work your way up to 1/4" or whatever size that makes the nut fit the hole tightly.  You only get one chance to drill, so step them up in size slowly to keep the original hole centers aligned, otherwise the carb will mount crooked. Once drilled, the nuts should fit very tightly, but be capable of being pushed into the holes if you were to push hard.  At this time, clean off any plastic millings and wood dust from the hole area.

Insert the nut into the hole from the engine side of the rear handle assembly.  Keep the nut flaps vertically aligned, so that they do not overlap where the intake boot passes through. Now stack some M5 washers onto a CS-8000 bolt. Through the hole you just drilled, screw the bolt into the new nut until finger tight. Put two dabs of gorilla glue or superglue behind the nut 'flaps'.  Use needle nose pliers to stabilize the nut from turning.  While continuing to hold the nut with needle nose plyers, use an allen key to screw the bolt into the nut.  As the washers make contact with the rear handle assembly, the nut will begin to pull into the hole you just drilled. Be sure to check and adjust the nut so that it will NOT interfere with the intake tube hole. Once the nut is fully seated, wipe the excess glue from the nuts, and ensure it doesn't touch the threads. Remove the bolt, then repeat the process for the other hole.

Once both nuts are seated, wipe the glue again.  The glue will help prevent the nuts from rotating freely over time. Wait about an hour for the glue to get its initial cure.  Now your ready to reassemble the saw.
Title: Re: CS-600P w/ HDA-203 and CS-8000 carb bolts (pics inside)
Post by: mbrogz3000 on September 13, 2013, 06:02:51 pm
Once you are ready to remount the new HDA-203 carb, turn the white fuel line L-fitting to about a 30 degree angle from its original position. This will route the fuel line under the carb.  Temporarily mount the carb through the airdam assembly, route the fuel line OVER the throttle linkage, then check and mark where the fuel line would need to go reach the fuel inlet of the carb.  Once you know where the fuel line would need routed through the air dam, remove the carb and air dam, then drill through the air dam using an appropriately size drill bit. File down the hole edges.  Remount the carb and air dam, then connect the fuel line. Check where the fuel line rests now on the base lip of the air dam. Place the air filter onto the air dam and push it into place. This will pinch the fuel line between the filter and the base lip of the air dam, and show where a clearance needs to be made on the base lip of the air dam. Mark where the pinch occurs on the base lip of the air dam, then cut a generous amount of base lip for the fuel line clearance. Once your happy with the fuel line, continue to adjusting the choke linkage.

For the choke adjustment, I am not going to describe how to do this, as its trial and error.  With the air dam and carb mounted, you need to make small adjustments to the choke linkage, flip over the choke tab on the carb, and continue adjusting until the choke can be locked rearward. My choke lever adjustment is still not 100%, but I am able to get the saw started as if were new.

Once the choke lever is working and your happy with it, the repair and mod is pretty much complete. See pictures for detail.

If you haven't already, remove the limiter caps from the carb. Sand down the taps, then replace them to the carb.  Screw the adjustment screws all the way in, CAREFULLY bottoming them, then set the L & H screws to 1.5 turns out.

Finish reassembling your air filter, install the bar and chain, fill with fuel mix, and attempt to start the saw. The saw should start as it normally would once the fuel gets cycled through the carb, but the chain may start spinning and the idle may be weird. Blip the thottle and wait. It should run idle without stalling. Once warmed up, tune the carb!
Title: Re: CS-600P w/ HDA-203 and CS-8000 carb nuts & bolts (pics inside)
Post by: sharkey on September 15, 2013, 10:56:36 pm
Good job and great pics.  It almost looks like that flange was made for those nuts and cap screws.  Echo built their reputation on things that last and I cant understand why they would cheap out on those carb mounts.  At least the cylinder is mounted with standard hex screws.  Now its time to open up those transfers and see what kind of power that engine can make!