getting it together
I have been procrastinating as I didn't want to keep shelling out $$$ for vacuum testing. It turns out that the local auto parts store has something called a Mityvac mv8000 on sale. It's a plastic handle, not as nice as some of the others I've seen, but it had all these really nice fittings, and was only $30. That's pretty much what I pay for a vac/pressure test.
I pressed in the seal. This didn't go as smoothly as I would have liked, but why should this part differ from the fun getting the old one out? Here's a pic, not pretty, but in, and straight:
I had a lot of difficulty keeping the seal straight, and found one side was just much harder to push in than the other. That's why there's a little marring on the metal outer ring on the seal between about 3:00 and 5:00 in the picture.
That part now out of the way, I cut up an old innertube, and blocked the exhaust port by sandwiching it between the port and the muffler. This worked well. I did the same with the carb, putting a piece of innertube between it and the rubber manifold (?). This was a bit of a trick as when sliding the carb in, it mates with the impulse line, making it impossible to connect the vacuum pump. I tried pulling the impulse line out of the way as I slid the carb in. It worked, but when I hooked up the pump, I could not pull any vacuum at all. When I pulled the line out of the way of the brass fitting on the carb, I actually pulled the other end off the barb connecting to the crankcase (duh). After my pulse returned to normal, I just removed the impulse line completely and routed it out the flywheel side. Things worked better after that. I pulled 10# vacuum, then walked away for 10 min. Still 10# when I got back.
I don't have an easy way of testing pressure integrity, so I opted to put soapy water on the seal and put 10psi into the impulse line using a compressor. No bubbles.
I started re-assembling, and discovered much to my delight that the process is actually, well, pretty straight forward. The saw was together before I knew it this morning. The brake linkage slowed me down a bit.
I clamped the bar in a vise and pulled slowly with the decomp valve open and choke on maybe 10 times just to get lubricant everywhere and...it burped anyway. Choke off, one pull, action. I tried to retune the carb, not sure if I've got it exactly right. I'm erring on the side of rich. I notice the saw is much much harder to pull without the decomp valve open. When I first got it, it was pretty easy to pull, with or without the decomp. New P&C, go figure.
I'm still waiting for a muffler to show up that I can mod, so for now it's just plain stock.
I then found my neighbour down the street bucking up a big birch tree using an ms290. He seemed a little unhappy, as he felt his saw was undergunned for the job. I offered to assist, maybe two little saws would make it bearable. Pretty convenient, this is 10 min after I got it running! His first comment when I put it into the wood was, "Hmmm, pretty sharp chain". We didn't time it, but the consensus was the little 260 is at least as fast as his 290. He may be right about the chain though, I think he stuck his in the ground.
Here's a clip from later on, cutting the knots out of a monkey-puzzle tree (buddy wants to make bowls out of the knotty pieces on his lathe):
Not a big magnum or anything, but I am just a home-owner after all.
I'll follow up if/when that muffler ever shows up, but for now, a very big Thank-You to all who gave great advice, hooked me up with manuals, parts, and removal/installation/test procedures. I'm really pleased with this saw, and especially pleased with all of this new-found knowledge. Need a bigger saw though.
I have been procrastinating as I didn't want to keep shelling out $$$ for vacuum testing. It turns out that the local auto parts store has something called a Mityvac mv8000 on sale. It's a plastic handle, not as nice as some of the others I've seen, but it had all these really nice fittings, and was only $30. That's pretty much what I pay for a vac/pressure test.
I pressed in the seal. This didn't go as smoothly as I would have liked, but why should this part differ from the fun getting the old one out? Here's a pic, not pretty, but in, and straight:
I had a lot of difficulty keeping the seal straight, and found one side was just much harder to push in than the other. That's why there's a little marring on the metal outer ring on the seal between about 3:00 and 5:00 in the picture.
That part now out of the way, I cut up an old innertube, and blocked the exhaust port by sandwiching it between the port and the muffler. This worked well. I did the same with the carb, putting a piece of innertube between it and the rubber manifold (?). This was a bit of a trick as when sliding the carb in, it mates with the impulse line, making it impossible to connect the vacuum pump. I tried pulling the impulse line out of the way as I slid the carb in. It worked, but when I hooked up the pump, I could not pull any vacuum at all. When I pulled the line out of the way of the brass fitting on the carb, I actually pulled the other end off the barb connecting to the crankcase (duh). After my pulse returned to normal, I just removed the impulse line completely and routed it out the flywheel side. Things worked better after that. I pulled 10# vacuum, then walked away for 10 min. Still 10# when I got back.
I don't have an easy way of testing pressure integrity, so I opted to put soapy water on the seal and put 10psi into the impulse line using a compressor. No bubbles.
I started re-assembling, and discovered much to my delight that the process is actually, well, pretty straight forward. The saw was together before I knew it this morning. The brake linkage slowed me down a bit.
I clamped the bar in a vise and pulled slowly with the decomp valve open and choke on maybe 10 times just to get lubricant everywhere and...it burped anyway. Choke off, one pull, action. I tried to retune the carb, not sure if I've got it exactly right. I'm erring on the side of rich. I notice the saw is much much harder to pull without the decomp valve open. When I first got it, it was pretty easy to pull, with or without the decomp. New P&C, go figure.
I'm still waiting for a muffler to show up that I can mod, so for now it's just plain stock.
I then found my neighbour down the street bucking up a big birch tree using an ms290. He seemed a little unhappy, as he felt his saw was undergunned for the job. I offered to assist, maybe two little saws would make it bearable. Pretty convenient, this is 10 min after I got it running! His first comment when I put it into the wood was, "Hmmm, pretty sharp chain". We didn't time it, but the consensus was the little 260 is at least as fast as his 290. He may be right about the chain though, I think he stuck his in the ground.
Here's a clip from later on, cutting the knots out of a monkey-puzzle tree (buddy wants to make bowls out of the knotty pieces on his lathe):
<object width="425" height="344"><param name="movie" value="http://www.youtube.com/v/1TnoOwPwZsA&hl=en&fs=1"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/1TnoOwPwZsA&hl=en&fs=1" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="425" height="344"></embed></object>
Not a big magnum or anything, but I am just a home-owner after all.
I'll follow up if/when that muffler ever shows up, but for now, a very big Thank-You to all who gave great advice, hooked me up with manuals, parts, and removal/installation/test procedures. I'm really pleased with this saw, and especially pleased with all of this new-found knowledge. Need a bigger saw though.
Last edited:
