Stumped!(pun intended)

[419GottaMinute]

Hello my good fellows and lasses,
First post, been lurking a while though...hopefully this thread is soisted in the right spot...on to the meat and potatoes!
I have an Echo cs3510, maybe 20 tanks through it, that has taken to interpretive dancing a paper weight.
The numbers:
120 psi cylinder, champion spark plug with GOOD blue pixies dancing, have checked the flywheel key way and crankshaft for deformity and they are pristine. I did have to swap out the coil for one off a 310, they were darn near identical visually and ohm wise. I m spraying fuel in the spark plug and plugging her back in and no chooch. Starter fluid, no chooch. Wide open throttle with the plug out and let her sit for 30 minutes, no chooch. Primer bulb pumps and gets hard, after 10 -15 pulls on the cord the plug is wet and fuel is dripping out the muffler. I checked the little air port for the fuel pump and it's clear. Screws are set to 2.5 out low, 3 out high. I even put a timing light and drill on her and damn near stripped out the crank bolt. Plug is firing before top dead center. I pulled the piston out of the head and visually inspected the skirt and rings, no dice. Cylinder and piston have superficial markings but so scratch's or grooves and the rings are intact. I am 100% aggravated and ready to chuck the saw. I m planning on purchasing a 550 or maybe ms 362(?) Used here in the next few weeks. I was looking at the 4910 because I really liked the power to weight ratio of these echos, but now I m gun shy. I would say I m mechanically inclined, I know it's getting fuel, compression and spark. It should be literally impossible for it not to run. Sorry for the novel, just wanted to provide and much details as possible. Please, please, for the love of saw, help me not throw this saw out the window doing 85. I appreciate your time, folks!

 

[J D]

120 psi cylinder

Try your compression tester on a running saw... if that 120 psi is accurate its not enough for a saw to run well, if at all

 

[pioneerguy600]

The primer bulb should never get hard all they do is pull fuel through the carb to displace air in the carb and then dump the fuel coming through back into the tank. Are the fuel lines connected correctly.?
While 120 lbs comp is not ideal the engine should still fire up on that if the spark is at the correct time. Did you have the flywheel off at any time? If the flywheel has slipped a bit the spark may be firing at the wrong time.

 

[419GottaMinute]

Try your compression tester on a running saw... if that 120 psi is accurate its not enough for a saw to run well, if at all

Thank you for your reply. Tested on known running husq450 and got 115 psi. Retested echo and 6 pulls got me to 135 psi, and held down to 115 for 3 minutes.

 

[419GottaMinute]

The primer bulb should never get hard all they do is pull fuel through the carb to displace air in the carb and then dump the fuel coming through back into the tank. Are the fuel lines connected correctly.?
While 120 lbs comp is not ideal the engine should still fire up on that if the spark is at the correct time. Did you have the flywheel off at any time? If the flywheel has slipped a bit the spark may be firing at the wrong time.

I have had the flywheel off multiple times, and the keyway is pristine with no wiggle room on the key. The key is part of the crankshaft, which I didn't even know was a thing before this saw. Fuel lines are routed according to the echo parts catalog exploded view. Hard is a exaggeration, upon rechecking....stuff is a better word to describe the primer bulb. Even is limes were routed incorrectly, wouldn't I still get chooch if spraying fuel into spark plug hole and reinstalling plug? I m not the sharpest tool in the shed, but I have always considered myself at least semi-mechanically inclined..this saw had me doubting my own sanity.

 

[419GottaMinute]

Edit: I did install a timing light and ran with drill. Light was firing btdc but I have no degree wheel to accurately list degrees btdc

 

[pioneerguy600]

I have had the flywheel off multiple times, and the keyway is pristine with no wiggle room on the key. The key is part of the crankshaft, which I didn't even know was a thing before this saw. Fuel lines are routed according to the echo parts catalog exploded view. Hard is a exaggeration, upon rechecking....stuff is a better word to describe the primer bulb. Even is limes were routed incorrectly, wouldn't I still get chooch if spraying fuel into spark plug hole and reinstalling plug? I m not the sharpest tool in the shed, but I have always considered myself at least semi-mechanically inclined..this saw had me doubting my own sanity.

If routed incorrectly you would not be spraying fuel into the engine since no line runs there but since you are such a great mechanic, then figure it out for yourself.

 

[419GottaMinute]

If routed incorrectly you would not be spraying fuel into the engine since no line runs there but since you are such a great mechanic, then figure it out for yourself.

Someone woke up on the wrong side of the bed! I ll chalk it up to miscommunication... I, in no way, meant to convey I was smarter than anyone here...as a matter of fact I commented to the exact opposite. I was clarifying that the saw should still fire off even if fuel lines were routed wrong, after spraying fuel in the spark plug hole. Even if it dont run, it should still fire off. For the sake of clarity, I posted in this site because most of not all of you are more experienced than I am with small engine and saws. Any helpful advice is greatly appreciated. This saw was impressive and now it's a 300$ doorstop. Thanks and happy v day

 

[pioneerguy600]

Someone woke up on the wrong side of the bed! I ll chalk it up to miscommunication... I, in no way, meant to convey I was smarter than anyone here...as a matter of fact I commented to the exact opposite. I was clarifying that the saw should still fire off even if fuel lines were routed wrong, after spraying fuel in the spark plug hole. Even if it dont run, it should still fire off. For the sake of clarity, I posted in this site because most of not all of you are more experienced than I am with small engine and saws. Any helpful advice is greatly appreciated. This saw was impressive and now it's a 300$ doorstop. Thanks and happy v day

Have a good one, best of luck.

 

[419GottaMinute]

Have a good one, best of luck.

I certainly hope you are not indicative of all moderators in this site. I posted hoping for advice, not zero patience and a catty attitude. Good day to you, sir.

 

[lloyd786]

Hello my good fellows and lasses,
First post, been lurking a while though...hopefully this thread is soisted in the right spot...on to the meat and potatoes!
I have an Echo cs3510, maybe 20 tanks through it, that has taken to interpretive dancing a paper weight.
The numbers:
120 psi cylinder, champion spark plug with GOOD blue pixies dancing, have checked the flywheel key way and crankshaft for deformity and they are pristine. I did have to swap out the coil for one off a 310, they were darn near identical visually and ohm wise. I m spraying fuel in the spark plug and plugging her back in and no chooch. Starter fluid, no chooch. Wide open throttle with the plug out and let her sit for 30 minutes, no chooch. Primer bulb pumps and gets hard, after 10 -15 pulls on the cord the plug is wet and fuel is dripping out the muffler. I checked the little air port for the fuel pump and it's clear. Screws are set to 2.5 out low, 3 out high. I even put a timing light and drill on her and damn near stripped out the crank bolt. Plug is firing before top dead center. I pulled the piston out of the head and visually inspected the skirt and rings, no dice. Cylinder and piston have superficial markings but so scratch's or grooves and the rings are intact. I am 100% aggravated and ready to chuck the saw. I m planning on purchasing a 550 or maybe ms 362(?) Used here in the next few weeks. I was looking at the 4910 because I really liked the power to weight ratio of these echos, but now I m gun shy. I would say I m mechanically inclined, I know it's getting fuel, compression and spark. It should be literally impossible for it not to run. Sorry for the novel, just wanted to provide and much details as possible. Please, please, for the love of saw, help me not throw this saw out the window doing 85. I appreciate your time, folks!

I’ve had to swap coils before and they may fit up perfectly but not the same timing. I put a rancher coil on a 450e and the saw would Stratton hard and when it ran it didn’t run good. A look at chain rotation showed it was running backwards.

 

[lloyd786]

Start, stupid autocorrect

 

[419GottaMinute]

I’ve had to swap coils before and they may fit up perfectly but not the same timing. I put a rancher coil on a 450e and the saw would Stratton hard and when it ran it didn’t run good. A look at chain rotation showed it was running backwards.

Thank you for the response. I guess now I have to decide if I like the saw enough to throw another $40 for a new oem coil.

 

[Defdice]

Just curious - what happened to the original coil that you had to switch it for a 310 coil? My 3510 has about the same number of tanks through it

 

[riprock]

Try 1 round out on the L and H screws

 

[lloyd786]

Thank you for the response. I guess now I have to decide if I like the saw enough to throw another $40 for a new oem coil.

Can sometimes find some good deals on parts on ebay.

 

[lone wolf]

Can sometimes find some good deals on parts on ebay.

Yup sometimes but most times prices are high.

 

[rwoods]

FWIW, I and some others have had plugs (even new ones) that fire outside the saw but not when installed. I would try a known good plug before buying another coil.

Ron

 

[lone wolf]

FWIW, I and some others have had plugs (even new ones) that fire outside the saw but not when installed. I would try a known good plug before buying another coil.

Ron

I just had one with a hairline crack in the porcelain.

 

[J D]

FWIW, I and some others have had plugs (even new ones) that fire outside the saw but not when installed. I would try a known good plug before buying another coil.

Ron

Agreed.
In the absence of a spark tester opening up the gap a bit when testing spark outside the cylinder will better represent the condition the coil needs to fire under in the cylinder