MS 180 c

[cal326]

I'm having some issues with one of these little saws... It was brought to me to fix with a hard start problem. If you could manage to get the thing started it would idle fine and shut off as soon as you pulled the throttle. I broke it all down, cleaned the spark arrestor screen, replaced the kinked fuel line, and put a new gasket kit in the carb. Now the saw will start every single time and runs fine as long as you are holding the throttle. As soon as you let off the gas the saw immediately shuts down. The saw is also running extremely rich now and it seems as though there might be a bit of residual fuel being spit back out the impulse line into the carb. i have never worked on any saw that doesn't have any high and low adjustments so i'm not sure if there is a trick to leaning the fuel air mixture out or not. i've tried to solve the idle issue by turning the idle screw in 1/4 turn increments from completely closed to wide open with no luck. if anyone has any ideas and could help me out i really need to get this saw fixed soon! I appreciate any information i can get.

 

[HD2010]

I recently had an issue with my 018C but opposite your problem. I would try adjusting metering valve. I bent the tab up on mine to get it to go full throttle. I would think you could bend yours down a little. It don't take much.

 

[cal326]

That is definitely on the right track with the metering lever. Does anybody happen to have any numbers to go with that? if i knew approximately how many thousands of an inch below gasket seat it would make this adjustment go much faster. I've tried it set to zama's recommended height and that is what cause my initial problem. I've been making minor adjustment back and forth for a while now and i just can't quite hit the sweet spot needed to sustain both idle and full speed. I can only get one or the other.

 

[RAMROD48]

Dont 180's have a single adjustment screw?

 

[russhd1997]

Dont 180's have a single adjustment screw?

The only adjustment screw is for idle speed. The other 2 are fixed jets.

 

[cal326]

unfortunately there is only the one screw for idle adjustment. I've spent all day bending and making extremely minute adjustments to the metering lever with no avail. I've gotten it so close to running properly but it seems like anything else i do to it just makes it worse than before. I've got it idling fine now and running almost as well until you get to a little bit past 3/4 throttle then it starts to have power surges and if you keep holding it at full throttle it will die after a minute or so. I'm running out of ideas and most of all patience. I've had about all i can take of this little saw...

 

[jbighump]

just worked on a ms290 that was doin the same thing ended up trying my carb on it and it ran like a champ id vot get a new carb mine was only 35 bux

 

[cal326]

I'm thinking that's what I'm gonna have to do. I'm fresh out of any other ideas.

 

[cal326]

I just wish i had a spare carb to try on it first to make sure buying a new one will solve my problem.

 

[motoman.5150]

What is your compression ? i just rebuilt 1, acted alot like yours , only had about 90lbs.

 

[formersawrep]

Did you used compressed air to blow it out?
It sounds like the nozzle/check valve/jet(I dont know the exact name of the piece) has been damaged. It looks like a piece of cardboard and it restricts/meters the fuel flow. If replaceable it is not worth it. Price a new carb. They are usually pretty cheap.

 

[Fish]

Take it apart again, this time remove the lever/spring/needle and hold up to a light, then blow air or some carb spray and hold up to a light again, and visually verify that the passage is clear. Also take a small screwdriver and remove the one little jet and make sure that it is claer as well.

 

[cal326]

I unfortunately don't have a compression tester at the moment. I dropped my old one and broke the gauge. Haven't gotten around to ordering a new one yet. I cleaned it with a small amount of carb cleaner and compressed air set at between 5 and 10 psi. I've done the same thing on numerous other carbs and never had an issue.

 

[cal326]

Take it apart again, this time remove the lever/spring/needle and hold up to a light, then blow air or some carb spray and hold up to a light again, and visually verify that the passage is clear. Also take a small screwdriver and remove the one little jet and make sure that it is claer as well.

Done that probably 100 times already. Every tiny little port is as clean and clear of debris as it's gonna be I've double checked every port before every adjustment I've made to the metering lever.

 

[Fish]

Done that probably 100 times already. Every tiny little port is as clean and clear of debris as it's gonna be I've double checked every port before every adjustment I've made to the metering lever.

The one under the needle?

 

[cal326]

Yup the one under the needle is nice and clean

 

[Fish]

pop the powerhead down to me in a box without bar/chain, and i will tell you what it needs.
you pay shipping both ways.

 

[cal326]

Sorry about that... I've been outta town for a little while now and i haven't gotten a chance to get back on here. I got it solved though. i'm not entirely sure what the problem was but i tracked down a friend of mine with the same saw that runs so i swapped the carbs and it fired right up just as it was supposed to so i just got a new carb for it and everything is working perfect now.

 

[roostersgt]

The more I work on saws, the more I've learned carb kits don't solve everything carb related. Sometimes you have to break down and replace worn out carbs. Frustrating as all get up when you can't get them rebuilt with a kit.