stihl ms180 smoke bomb

[Robin Rowley]

What is the height of that tab/lever?

It's pretty impossible to measure accurately, but I'm thinking around 1.2 mm or so

 

[SteveSr]

It's pretty impossible to measure accurately, but I'm thinking around 1.2 mm or so

Lookup a "Zama" Z gauge for the C1Q carb. It may just be a straight edge across the carb casting.

 

[Robin Rowley]

Thanks, SteveSr. I was measuring it all wrong. It's close to zero, maybe 0.05 mm.

 

[HarleyT]

I would be interested in seeing if the needle was sealing.

 

[Robin Rowley]

I'm afraid I don't have the necessary tools for that. Would something like a mityvac work for that? I've been meaning to get one of those for decades. This might finally be a good excuse to get one.

 

[HarleyT]

You could just get some fuel line tubing, and put the carb back together halfway, the side with the one screw through the center. Hook the line up, and with the disassemble side up, put some fluid in the cavity, and blow through the tubing lightly, if the needle isn't sealing, you would see bubbles.

 

[Robin Rowley]

This is the cavity you're talking about?

 

[HarleyT]

Yeah, just so some fluid covers the inlet needle. With a light blow, you should not see any bubbles.

 

[SteveSr]

I'm afraid I don't have the necessary tools for that. Would something like a mityvac work for that? I've been meaning to get one of those for decades. This might finally be a good excuse to get one.

Yes, a Mityvac 8500 kit will do pressure and vacuum. The fuel inlet of the carb should hold off 10psi indefinitely. This is the #1 test on a carb, especially if it is flooding or running rich.

You should also check the metering diaphragm. It should be nice and pliable and not "crinkly" which could hold the needle open. This shouldn't be a problem for a 2 year old saw unless you got a hold of some bad gas or stored the saw with gas in it.

Usually these saws run lean as sin. About the only thing that can screw it up is clogged air filter or spark screen, and possibly part throttle operation. Saws are designed to run wide open in the wood.

 

[GrizG]

This is the cavity you're talking about?

You guys still doing cavity searches?

 

[Robin Rowley]

No bubbles in the cavity. And diaphragm looks fine too. I do indeed not run the saw at wide open very much. Being that it's a small little saw I use it a lot for clearing underbrush, small bushes, etc. So it idles a good bit. And that's when it smokes like a smoke bomb. No mosquitoes or gnats! I think I'm going to clean the air filter and put ole smoky back together. Maybe change brand of oil and see if that helps any. Thanks for all the great help guys. I've even learned a little about chainsaw carbs!

 

[HarleyT]

We don't believe in cavities here in Ky!!!!

 

[Patrick1903]

No bubbles in the cavity. And diaphragm looks fine too. I do indeed not run the saw at wide open very much. Being that it's a small little saw I use it a lot for clearing underbrush, small bushes, etc. So it idles a good bit. And that's when it smokes like a smoke bomb. No mosquitoes or gnats! I think I'm going to clean the air filter and put ole smoky back together. Maybe change brand of oil and see if that helps any. Thanks for all the great help guys. I've even learned a little about chainsaw carbs!

Had the muffler ever been off the saw before? Your pic appears to show a lot of exhausted oil on cylinder, etc. Hopefully with new plug, new air filter, fresh fuel and accurate mix, and a good seal between cylinder exhaust, you will run less Smokey…after cleaning the cylinder and muffler. Cut some wood for a few minutes and get that saw hotter…burn the oil off.

 

[GrizG]

No bubbles in the cavity. And diaphragm looks fine too. I do indeed not run the saw at wide open very much. Being that it's a small little saw I use it a lot for clearing underbrush, small bushes, etc. So it idles a good bit. And that's when it smokes like a smoke bomb. No mosquitoes or gnats! I think I'm going to clean the air filter and put ole smoky back together. Maybe change brand of oil and see if that helps any. Thanks for all the great help guys. I've even learned a little about chainsaw carbs!

I'd put a muffler gasket on it too... My 170 leaked exhaust oil down the outside of the cylinder as there was no gasket from the factory. The gasket solved that problem... kept the oil in the muffler and going out the proper hole!

 

[Chevboy0167]

Update... perhaps this IS the sealant they are using for welch plugs in newer carbs. Criteria and color fit... maybe???

 

[SteveSr]

Update... perhaps this IS the sealant they are using for welch plugs in newer carbs. Criteria and color fit... maybe???

View attachment 1033235 View attachment 1033236 View attachment 1033237 View attachment 1033238

I doubt it. Very few glues/adhesives are resistant to BOTH gasoline AND alcohol. The old green sealant that Zama used couldn't take the alcohol.

The exposure is also different for a thread sealant. It is forced between threads and only a small amount of the sealant is exposed to the gas/alcohol mixture.

As a test make 2 samples painted on top of extra welch plugs. Put one sample in a small glass jar filled with Non-E gas and the other in a jar of E10, E15, E85. See what shape the samples are in after it sits a while.

 

[Chevboy0167]

^^^^ I was just thinking that after I got it. I may have a few Chicom carbs floating around for test mules. May be a bit as it's 21* here now.... no thanks. I will get at it when it hits around the 30's at the least as I have a non-heated shop. I will start a new thread in the future with updates.

 

[Bill G]

Did you ever get to the root of the problem

 

[coffeebrk]

I do indeed not run the saw at wide open very much. Being that it's a small little saw I use it a lot for clearing underbrush, small bushes, etc. So it idles a good bit.

Did you ever get to the root of the problem

Not running at WOT, fouling sparkplug, questionable fuel mix and age, dirty air filter......

 

[samaritan]

We don't believe in cavities here in Ky!!!!

View attachment 1032503

Thats what the rest of the world thinks we all look like, lol! Im livin here now and once thought that too, being from Jersey ( a good place to be FROM)