8800 Rebuild

[lesorubcheek]

Decided to share a rebuild of an 8800. Been putting this one off for awhile and decided it needed to get into gear. Started with a 8800 in pretty good shape other than a fried piston and scuffed up cylinder.

Plan is to make it a work saw, but what the hay, might as well pretty it up a bit to start with. Saw was torn down, repainted on the outside and cleaned up as good as possible on the inside. I used 400 grit emory cloth on my table saw with plenty of WD-40 to lightly surface the faces of the case halves.

New bearings were installed since I had 'em. Old ones would have worked, but hey, why not. Trusty heat gun and a little bit of time at the press and its starting its trip back together.



Not shown in the photos, but there's 2 alignment dowels used to align the case halves. These go in aided by a little heat on the case to make a smooth fit.

Cleaned the crank/rod assembly repeatedly with carb cleaner and acetone with plenty of air for blowing it clean. A little more heat on the bearing and a very light press puts the crank onto one half.



Next step was to join the case. I decided to use Threebond 1194. Used a small paint brush and very lightly applied to one side. Heat gun on the bearing and another visit to the press.



Here's the tools I used to press the halves together. They fit over the crank and engage the inner race of the bearings. This reduces bearing stress when pressing together. Really overkill though since the parts went togther very smoothly.



There's 5 bolts that hold the case together. 4 are around the crank and the 5th is located in the lower front portion. A little red Loctite and torqued all bolts to 80 in-lbs.



The two of the cylinder nuts on the flywheel side are secured by retainers. These slide into place. Also installed the carb pulse nipple since it was removed during cleanup.

The piston is fitted next. The locating pins for the rings need to be located on the inlet side, so they face rearward.



Heated the piston just a bit and a little lube to make the pin slide in easy. Also a good dose of oil on the rod bearing prior to install. After the pin is inserted, the retaining circlip is snapped into place.

Here's a pic of the new cylinder. Looked pretty good as it came in the box, so no honing. Just gave it thorough cleaning.



Stay tuned... more to come.

Dan

[farley9n]

Beautiful! Great Start! One of my favorite saws and a real power house. I will be bringing my 540 to the Pacific Northwest GTG for anyone to try. I also have another that I am going to make into an 8800.......Keep up the good work.....Thanks....Bob

[OBR]

I looked on the acres site and couldn't find any specs on the 8800 so what are the differences between the 8800's and 540/545's ?

[lesorubcheek]

Apr 28, 2009 10:28:03 GMT -5 OBR said:

I looked on the acres site and couldn't find any specs on the 8800 so what are the differences between the 8800's and 540/545's ?

Great question!
I don't know anything about the 545, but I'll list the things I do know about the 540 vs the 8800.

Cylinder - Open transfers on the 540, closed on the 8800. There's a difference in the slope of the cooling fins and a different attachment for the exhaust.
Piston - Different design due to transfers.
Rings - thin rings on 540, "normal" rings on 8800.
Rear handle assembly - plastic on 540, magnesium on 8800.

Saws have different mufflers. Fuel/oil caps are different due to the plactic vs. mag tanks.

I'm sure I've left off a few more items. Have to look, but I think a few parts dealing with the inlet are different.

I'm still not sure which one was first produced Anybody know?

Dan

[OBR]

Great info Dan! Its really looking good. I think it would be sweet to see more guys projects like this.

[farley9n]

Outwardly they are very similar but there is a big difference in the cylinder and it's related parts. The 8800 cylinder and piston will go right on to a 540 but you will have to also use the 8800 muffler and intake manifold as there are differences in the size and shape of those ports. The 540 has open transfer ports and the 8800's are the more desireable closed type. There is also a change in the cylinder finning. It's my opinion that some of these changes were in responce to over heating in the 540.
I have make the change to 8800 in a friends 540 and it did run strong but I haven't that saw here to compare to my 540. I have side by side pictures of the differences in the cylinders but will have to learn how to post them if anyone is interested.....Bob

[lesorubcheek]

Apr 28, 2009 10:59:18 GMT -5 farley9n said:

It's my opinion that some of these changes were in responce to over heating in the 540.

Right on with the info. I've kinda assumed this to be true as well based on some reports of the 540 which indicate the 540 musta been first.

One big puzzler is why the heck did they also change the tanks from plastic to magnesium??? You'd think that plastic was the "future" so the tank design change seems in reverse. A good mystery to solve.

Dan

[OBR]

Yes, I would agree that it does seem somewhat backwards. Though I would be interested to find out exactly when each model was made. I would assume the 545 was a later revision of the 540 as well, so I would be curious as to how it relates to the 8800 as far as mechanical aspects and the materials used to build it (mag. vs plastic). But I for one am ready to see some more of the 8800 build for sure!

[chainsawwhisperer]

Dan, your project looks great!
I'm jelious though, I have a brand new jug and piston, and can't find a blown-up 8800
I t was with a blown up MP88 saw I got a while ago.
I can't wait to see your finished saw!
Jim

[lesorubcheek]

Round 2....

Time to put on the cylinder. First, I made sure I had oiled all the bearing surfaces as well as the rings and around the piston and cylinder. Next, clean the mating surfaces with acetone. Using a piston ring compressor from Bailey's made it easy. There's a thin paper type gasket for the cylinder base.



Each bolt has a conical washer. The wide base of each washer lies down on the cylinder. A long reach hex blade with a torque wrench set at 85 in-lbs seals her up. The nuts are self locking, but a little blue Loctite never hurts.

Next its time to install the seals. I used the same "tool" that was used for the bearing to press on the flywheel side seal. Just a bit of silicone around the perimeter never hurts. I also oiled the lip well and al bit on the crank so it would go on without damage.



The seal on the clutch side is inside the oil pump housing. A little silicone around the base of the pump is used since there's no gasket. Just make sure none gets into the oiler hole! Two bolts secure it torqued to 25 in-lbs.



So, with the case hopefully sealed up, next step before moving on was to do a vac and pressure test to make sure there were no leaks. Made some block off plates outa aluminum and used gasket material with a dab of sealant. I like old inner tubes, but forgot to bring some from the farm.





Since there's a nipple for the pulse line, this is a perfect spot for connection. I use an old vac/pressure gauge with a blood pressue bulb for pressure and a Mityvac for the vaccuum. I used 5 lbs pressure and vac and let her sit for a few minutes. Everything looked good.






Next, I'll start preparing the rear handle / tank assembly.

Dan

[lesorubcheek]

The rear handle / tank assembly is made from magnesium on the 8800, or at least this one is. The paint was very hard, almost like it may have been a powder coat. It was missing alot of paint underneath, but the sides and top looked good. I decided not to strip it, but sand over the existing paint and give it an overspray. So, everthing was removed, cleaned, prepped, painted and dried. There's a few rough edges where the paint blends with the bottom, but its supposed to be a working saw anyway right!





Decided to get the lines installed as the first step of reassembly. Cut the ends at an angle, tie some fishing line and feed it through the hole. Then pull it through along with fuel line.



There's a vent line for the oil and gas that use a duckbill inside the tanks and a fuel filter on the outside. These duckbills are a bit larger than the ones used on just about everything else. A metal tube connects the duckbills to the line.



After the 2 vents goes the fuel line and oil line. Filters for each attach and all the lines trimmed to approximate length. Always a good idea to leave 'em a little long and trim them to exact length after everthing is installed. The trigger and safety interlock, grommets, and a part that mates with the intake boot go on to finish it up, along with re-sticking the UT/Serial # label.



The muffler needs a little cleanup, so I'll probably handle that next.

Dan

[lesorubcheek]

Got the muffler cleaned up good. I'll put it on later. Ran into the first little roadblock. There's a strip of thermal insulation that glues onto the housing to the left of the muffler. Luck would have it that I couldn't find any decent glue to get the thing to stick. So, the muffler will end up being a bit later.

Decided to put the flywheel on next. Key was removed, so it was first reinstalled, then the flywheel, washer and locking nut. Torque to 25 ft-lbs.



Next, put on the oil line at the pump. The oil line is in 2 parts with a plastic connector joining them. Makes it alot easier to separate the handle from the crankcase.


After the line is installed, there's a cover with 2 small bolts. Blue Loctite and 35 in-lbs torque.



Next is the intake boot. There's a gasket, a plastic block, the boot, and a metal frame that holds it all in place. 4 bolts with blue Loctite at 20 in-lbs.



Time to put the vibration isolators into the handle assembly. There's 3 on each side. Similar to a 410, but these have a larger hole in the center of the rubber isolator and a hard plastic insert goes into these. Make sure to push these in as far as possible, since its a snug fit.



Before joining up, the oil lines need connecting, and the impulse line for the carb needs to be fit onto the nipple on the crankcase.



Joining it up was fun . I started with the front isolators and worked up. Had to press and pry as I went to ease them all into place. With the new rubber isolators, it was very snug.



As it worked into place, don't forget about the boot! It needs to push through the retainer on the handle assembly. If you're not careful, it can tear.

So finally with all the buffers in place, its time to secure the retaining bolts. These are tightened to 65 in-lbs, with some blue Loctite for good measure.


Its finally starting to look like a saw. Ignition, carb, muffler and a few odds and ends, and its ready for business.

Dan

[lesorubcheek]

Still haven't found a suitable adhesive to stick that heat pad on. I got some stuff that's supposed to be fuel resistant, but it ain't sticking worth crap. I think I have some 3M spray on left at the farm, so the muffler is on hold til I get this solved.

Had my first big "ahhh crap" with the saw. Pulled the bar studs using some spacers and tightened the nuts to pull them through. I should have used the press and put them in with it before assembling the case halves. A big chink of paint stripped off as the washer on the front stud spun . Oh well, it is supposed to be a work saws right!


OK, so after getting over the disappointment, I decided to get the carb ready. The Walbro WJ is about as easy a carb to work on as they come. I'll do a step by step on what I did. First was the disassembly and cleanup. I used carb cleaner and compressed air. No governer valves on this one to worry about blowing out. Didn't remove the plugs since I'm pretty sure the carb was OK prior to the piston incident. After cleanup, here's all the parts complete with a new diaphragm gasket set. Note the flange that protrudes on the front of the carb. This is what slides into the inner part of the boot to mate and seal the inlet. Make sure its smooth with no nicks so it'll seal well.



The fuel valves lay on the carb body and the gasket goes over them.


Then, the top goes on and secured with 4 screws.



Here's what it looks like on the bottom.


First thing is to put in the needle. I used a new one even though it didn't come with the gasket set.


Next is the spring.


The lever goes in next. There's a groove that need to slide into the needle, and then a small dimple that sits over the spring.


Secure the lever with the screw. I used a bit of blue Loctite here since there's no lock washer.


Next step is to make sure the lever is adjusted to the correct height. The little Walbro tool works great for this.


On the bottom, the gasket goes first...


and then the diaphragm. This one has a groove that needs to slide into the lever as its put into place.


Now its time to secure the bottom cover. 4 more screws and its done.


Last job is the mixture needles and idle speed screw.


Can't mix 'em up since they're different lengths. After seating, both are backed off 1-1/4 turn for an initial setting.


Idle speed screw turned in just enough to lightly unseat the throttle and its ready to go.


Putting the carb in is a bit tricky, but not too bad. I lightly oiled the inner portion of the boot so the flange on the carb would slide in easy. The throttle rod needs to be inserted on the carb's throttle fitting while its free. Next, angle the metering levers into the rubber dust shield and slide them in until the carb is centered with the hole in the boot. Slide the carb forward into the boot. There's a shield and gasket on the rear of the carb that need to be in place before inserting the 2 bolts that secure the carb. Book recommended red Loctite on the carb bolts. After tightening up, the pulse and fuel line can go in place. Final step is the choke rod. There's a brass securing pin that's a little tricky to get into place. Needle nose pliers and a bit of patience, and its all ready to go.


Dan

[lesorubcheek]

Decided to do the ignition next. The module is secured by 2 bolts and use a nylon spacer washer between the module core and the case housing. Spacing from the flywheel is 0.012".


After the module is secured, a plastic cover is put in place and the wires routed along it through a couple slots and clamping locations.


The wires for the kill switch wind around and out the rear.


The switch is attached to the wires and held in place inside a small plastic housing.


A tab and a single screw secures the housing to the saw.


Next is the starter housing. Here's all the parts that make it up. I decided to reuse the starter cord since its in OK shape.


First step is installing the rewind spring. Its contained in a special black plastic housing. I cleaned it well and used a bit of WD-40 for a light lube to prevent rust. Two screws hold it in place.


The cord is inserted into the slot on the pulley and overlapped as shown.


A pressed-on retaining ring secured the rope on the pulley.


The cord is inserted through the opening in the housing and the pulley placed onto the post.


A plastic bushing goes on between the pulley and the post. I used a bit of grease for lube here. A washer and a bolt secure it in place. The other end of the cord gets the grip installed.


Here's where the neat little trick of tensioning the pulley is done. With a loop of slack cord pulled through the dimple in the starter pulley, wind around clockwise 3-4 rotations to load up tension on the spring. Then pull the cord through with the starter handle and see if its properly tensioned. If it droops, repeat and give another rotation.


So here it is, starter pulley ready to be installed. I debated polishing it up, but decided it wouldn't be worth the time.


Installation uses 4 bolts with washers to hold it in place. A little Loctice is a good idea on these. Pull the cord out a bit and as you sit the starter in place over the pawls, let it retract. This action lets the pulley slide in between the pawls.


Found the 3M Super 77 spray adhesive at the farm and looks like it'll do the trick to secure the insulating pad.


The front handle seemed like a good next step. There's a nut that's internal to the air chamber that has to be held in place to install the handle. It works, but doesn't seem the smartest of design ideas. It means you have to first remove the air filter and the chamber cover before you can remove the handle and reverse is true for assembly!


So, there's two bolts on the side...


and 2 underneath in the front.


Not very much left to go now. Hopefully one or at most 2 more posts to wrap it up.

Dan

[farley9n]

Excellent work and documentation! Super photos! Once you get it going your really going to be pleased with it's combination of speed and power. It's amazing how much you can lean on it with a 32" bar and how good a speed it will maintain in the cut! It's a bit heavy by todays standards but a quality saw under appreciated for it's time. THANKS for your fine post!.....Bob

[lesorubcheek]

Thanks Bob! Never lifted any new saws close to this one in size, so I can't compare its weight. It feels pretty light compared to my dad's David Bradley! Anxious to get her finished up.

Dan

[lesorubcheek]

Been a little busy on other stuff lately, but here's a bit more.

Muffler parts are easy enough to figure out. Here's all of 'em scattered to show what's used. I painted over it with some high heat paint.


and here it is on the saw. Had to remember to take out the wad of paper stuffed in there to keep the inside free from stray particles!


With the handle bar in place, the air box cover can now go in place. The rubber gasket underneath looked in good shape, so all that was needed was to install it with the 4 screws.


Next is the air filter. Hope I don't damage it 'cause I never see any spares for these.


...and the cover just screws on top.


Next comes the clutch. Here's all the parts. Notice the notches in the drive gear and on the sprocket. The sprocket actually turns the drive gear so it only oils when the chain is turning. Its a nice conception, but the downside is having a unique sprocket that fits this saw and no tohers.


A spacer goes underneath the drive gear.


I put on a 7 tooth 3/8 sprocket. Clutch assembly is easy enough using the "rope through the plug hole" trick.


About all that's left is picking a bar/chain combo, top cover and a few odds and ends. I hope by the middle of the week I can have it finished up.

Dan

[lesorubcheek]

Well, its finished! Tried it out on some small pine logs and it does cut nicely.

There wasn't too much work left to finish her up. Put in the spark plug and then the upper cylinder cover. Chain catcher, bar plates, bumper spikes, bar and chain and the cover. Chain brake works normally and nothing to do other than clean it up.







Fired first time after 6 or 7 pulls. Smoked a bit due to the excess oil used during assembly and then smoothed out nicely. A little final carb adjusting and she was begging to run. Now I need to find some trees big enough to run it properly and see how it'll cut.

Dan

[redsqwrl]

Beautiful Job.

I will PM my address, You can just send that normal, no need to overnight it.

Thanks again for doing such a nice job on my saw.

I have a pile of hardwood logs calling that saws name. Give a listen to the north and I am sure you can hear it.

Nice work,
RS

[RandyMac]

One heck of a job, and everything was rightside up.

Are you going to refinish the airbox cover or did I miss that stage?