661 not running right

[Fil01]

I know there are tons of discussion about 661 problems and i red them all but I can’t figure out what my saw has. The saw was initially running only on idle so I cleaned the carb changed the black solenoid with a white one and installed a new orange filter. (The coil is the A one)
The saw ran great in November then I put it away and restated it this weekend.it Started great, warmed it up and made three cuts then died. I checked the plug after trying to restart it for 10 minutes and I found it completely dry. Then tried again and flooded it. The saw would pop after I dried the plug but nothing more.
Ps the gas I used was the premixed from stihl but was pretty old.
Should I change the solenoid again?
Could new carb diagrams solve the problem s?
Pardon me for the length but I’m in a hurry and need to get the saw running

 

[cscltd]

Carb diaphragms may need replacement or something not done right when you cleaned carb
premixed fuel is good for 5 years if factory sealed, 2 years within that 5 years if unsealed
from what I understand you can only change from black to white solenoid valve if you change the ignition module to match. (Stihl sold conversation kit)
you have version 1 module mixed with version 3 valve.

 

[Fil01]

Carb diaphragms may need replacement or something not done right when you cleaned carb
premixed fuel is good for 5 years if factory sealed, 2 years within that 5 years if unsealed
from what I understand you can only change from black to white solenoid valve if you change the ignition module to match. (Stihl sold conversation kit)
you have version 1 module mixed with version 3 valve.

I’ll check the diaphragms again even if they looked good. I changed the black solenoid with the white one after watching a video on YouTube about the updated solenoids and from what I read my coil should work whit the white valve, Even because it worked fine in November.

 

[gary courtney]

When I changed over to the white solenoid I also changed the coil per Stihl factory reps. instruction.Did thereadjustment steps and never looked back.

 

[Fil01]

Carb diaphragms may need replacement or something not done right when you cleaned carb
premixed fuel is good for 5 years if factory sealed, 2 years within that 5 years if unsealed
from what I understand you can only change from black to white solenoid valve if you change the ignition module to match. (Stihl sold conversation kit)
you have version 1 module mixed with version 3 valve.

I checked and the 4701A should run well with the white solenoid and orange filter. The 4701A is one of the latest version. Could be a bad solenoid oring?

 

[cscltd]

6. Repair kit M-Tronic 6.1 Explanation In order to fit previous versions of chain saws with the new dust-resistant solenoid valve, b 5, an MTronic repair kit is available. The kit includes the following components: – Solenoid valve 0000 120 5104 – Control unit 1144 400 4704 – Pickup body 0000 350 3518 Chain saws of previous versions can also be calibrated with the control unit 1144 400 4704. After installation of the new components, the chain saw must be calibrated in conjunction with the STIHL Diagnostic Software, b 6.2
-as per Stihl tec info 89.2017
-not youtube

 

[Fil01]

6. Repair kit M-Tronic 6.1 Explanation In order to fit previous versions of chain saws with the new dust-resistant solenoid valve, b 5, an MTronic repair kit is available. The kit includes the following components: – Solenoid valve 0000 120 5104 – Control unit 1144 400 4704 – Pickup body 0000 350 3518 Chain saws of previous versions can also be calibrated with the control unit 1144 400 4704. After installation of the new components, the chain saw must be calibrated in conjunction with the STIHL Diagnostic Software, b 6.2
-as per Stihl tec info 89.2017
-not youtube

Ok so this kit fits the old flywheel and carb right? And since I already have the updated solenoid and filter I should solve the problem with the 4704 coil and calibrating the system?

 

[Fil01]

When I changed over to the white solenoid I also changed the coil per Stihl factory reps. instruction.Did thereadjustment steps and never looked back.

Which coil did you install?

 

[cscltd]

i think the control unit (coil) is changed again to 1144 400 4705?
kit # 1144 007 1801
could have defective valve? did u touch end it with fingers or drop when installing(like touching a halogen bulb with fingers)
i dont know what running characteristics are when mix matched, but could have long term problem with cyl?
put the old one back in and see if that helps if still have it

 

[Fil01]

i think the control unit (coil) is changed again to 1144 400 4705?
kit # 1144 007 1801
could have defective valve? did u touch end it with fingers or drop when installing(like touching a halogen bulb with fingers)
i dont know what running characteristics are when mix matched, but could have long term problem with cyl?
put the old one back in and see if that helps if still have it

Tried to start it tonight and after 20 pulls the plug was bone dry. I think I’m going to buy a new coil 7104 and try that or buy a new black solenoid which would be cheaper.
Btw the solenoid was installed correctly and ran fine for an entire day, that what drives me mad. Probably the mix match causes those symptoms, I’ll se if a diagnose from the dealer helps

 

[cscltd]

try putting a tea spoon of mixed fuel down plug hole and see if it fires

 

[Fil01]

try putting a tea spoon of mixed fuel down plug hole and see if it fires

Yep fires runs for a bit then floods

 

[SAWMIKAZE]

Tried to start it tonight and after 20 pulls the plug was bone dry. I think I’m going to buy a new coil 7104 and try that or buy a new black solenoid which would be cheaper.
Btw the solenoid was installed correctly and ran fine for an entire day, that what drives me mad. Probably the mix match causes those symptoms, I’ll se if a diagnose from the dealer helps

I've put a white solenoid in every early version of 661 that's been made and it worked perfect, I'd say you have another issue.

 

[gary courtney]

Which coil did you install?

Stihl USA tells me you can only use 4702A coil/CM with white solenoid.

 

[SAWMIKAZE]

Stihl USA tells me you can only use 4702A coil/CM with white solenoid.

They say that but countless people have found out otherwise.

You know how they are, they told me I couldn't put an oil pump from a 461 in my 361 either....

 

[gary courtney]

They say that but countless people have found out otherwise.

You know how they are, they told me I couldn't put an oil pump from a 461 in my 361 either....

Yep, Stihl and Harley- Davidson are quite alike!

 

[Smitty Smithsonite]

Not much to a saw, as with any engine when you get right down to it. Fuel, air, compression, TIMED ignition. Gotta have all 4. If the rings didn't suffer some odd failure and it still has good compression, it's either air, fuel or spark.

My way of ruling out many problems is to remove the air filter and give the carb a little sniff of acetone, brake clean, or ether. If it fires and dies, you've diagnosed everything and are left with only a fuel problem. If it fires it has compression, air, and TIMED ignition.

One caveat is, on some small 2-strokes, this doesn't work! You have to get just the right amount of whatever flammable spray you're using, or else it acts like it's got no spark. Even then sometimes it won't fire unless you've got a working carburetor on there. That can make things a little frustrating. If it does work, it makes things easy. If it doesn't, now you need to see if you've got spark by actually checking for it. If it's got it (and it's strong), and it still won't start and you're certain the carburetor is 100% clean and adjusted correctly, then it could've had a flywheel nut come loose and shear the key, throwing ignition timing way out. Not as common, but I've seen it more than once.

 

[Fil01]

Not much to a saw, as with any engine when you get right down to it. Fuel, air, compression, TIMED ignition. Gotta have all 4. If the rings didn't suffer some odd failure and it still has good compression, it's either air, fuel or spark.

My way of ruling out many problems is to remove the air filter and give the carb a little sniff of acetone, brake clean, or ether. If it fires and dies, you've diagnosed everything and are left with only a fuel problem. If it fires it has compression, air, and TIMED ignition.

One caveat is, on some small 2-strokes, this doesn't work! You have to get just the right amount of whatever flammable spray you're using, or else it acts like it's got no spark. Even then sometimes it won't fire unless you've got a working carburetor on there. That can make things a little frustrating. If it does work, it makes things easy. If it doesn't, now you need to see if you've got spark by actually checking for it. If it's got it (and it's strong), and it still won't start and you're certain the carburetor is 100% clean and adjusted correctly, then it could've had a flywheel nut come loose and shear the key, throwing ignition timing way out. Not as common, but I've seen it more than once.

I’ll check the flywheel key for timing. Compression is great, no sign of scoring. As for spark I can’t test it because the Mtronic needs the special tool but by putting fuel in the cylinder it fires up. I’ll try a new coil, I’ve asked for the 4704 (67€) but I’d like the complete kit so I know the solenoid and the coil match each other

 

[2100hpS10]

I don't know much but sounds like you have a carb problem... maybe a passage or jet clogged since your're not getting fuel. What about the fuel filter? Hose from cylinder to carb?

 

[Smitty Smithsonite]

I’ll check the flywheel key for timing. Compression is great, no sign of scoring. As for spark I can’t test it because the Mtronic needs the special tool but by putting fuel in the cylinder it fires up. I’ll try a new coil, I’ve asked for the 4704 (67€) but I’d like the complete kit so I know the solenoid and the coil match each other

If it fires up, you don't need a coil. You need to check out the entire fuel system. Dump and flush the tank, clean and adjust the carb, and make sure the fuel filter isn't stopped up, and all the lines are pinhole, and leak-free.