6 mo old ms170 will not start

[etbrown4]

I know, all we need is fuel, spark, air and compression.

Filter is new, and this puppy won't even try to start on a little carb cleaner !
So, yes I've tried a new plug, and spark testing. I can see a blue spark at the plug.

I've tried a spark testing tool. This saw will spark with a 4mm gap on the tester, but nothing greater. I know that translates to kva or the strength of the spark.

My old trusty Mcculloch will spark at a 6mm gap so naturally it's stronger.

Anybody tested a ms170 with a spark tester to know that lighting up a 4mm gap is strong enough? Or other tests?

 

[Slemaydel]

I own one of these. It has been pretty reliable. I run the canned premixed gas. I know it's expensive but I don't run a saw for a living so it's worth it to me. That being said about 3 years into owning this saw I had to deal with a no start like you are dealing with. I ended up changing spark plug, air filter and then had to adjust the idle after getting myself out of the mind that the carb was the problem. It still does not start very easy. 4-7x pull with choke then same with no choke then usually I have to do that two or three times to catch it long enough to grab the throttle. Once it's hot it runs perfect.

Good luck with the troubles.

 

[etbrown4]

Going deeper, the cold compression is about 135. Should be enough to start.

As with some other posts, I can't get a pop. Pulled plug, turned it upside down and out came maybe an ounce of premix. I'll air it out overnight and try again tomorrow.

Did read a post where an old guy lightly preheats his plug tip with a torch, squirts in some carb cleaner with good success.

Will update tomorrow, but that 4mm max gap on the spark tester still seems on the low side.

 

[RiverLogger]

Have you checked the spark arrestor screen? Had a 180 that wouldn’t run due to a clogged screen.

 

[etbrown4]

Checked screen, it's clear. Piston and rings look brand new.

 

[Okie]

I would check the warranty papers if it NEW. (you say it's 6 mo's old)
Before I did something that might void a warranty.

 

[irhunter]

If under warranty...do that.

Compression, new plug, clean muffler, good-looking piston, has spark, won't pop with 1/4-teaspoon of mix down the plug hole = either air leak or sheared flywheel key.

Roy

 

[super3]

As with some other posts, I can't get a pop. Pulled plug, turned it upside down and out came maybe an ounce of premix. I'll air it out overnight and try again tomorrow.

Flooded. After you let it air over night don't use choke. Hold throttle wide open untill it starts and keep the revs up until it cleans out b4 going back to idle.

 

[coffeebrk]

Fuel put into oil tank and oil put into fuel tank.

 

[Captain Bruce]

I would check the warranty papers if it NEW. (you say it's 6 mo's old)
Before I did something that might void a warranty.

MS170/180 units had an on-going service issue. The intact boot was sloppy, and would leak, and/or come loose. That same mfger./supplier provided boots for the early MS192/193's. Same issue. Replace OEM boot with new part #, re-assemble unit, go to work.

 

[J D]

Going deeper, the cold compression is about 135. Should be enough to start.

135 isn't great... it should run, but if your gauge is accurate (& designed for small motors) it's definitely on the low side.
If it could be flooded remove plug, turn upside down & pull over a bunch of times (make sure ignition is off). If you are getting fuel out then once it's cleared try starting without choke & throttle held wide open. It can help to have an assistant for that... & maybe remove the bar/ chain to be safe

 

[stihltech]

6 months old? Stihl's problem. DO NOT disassemble.

 

[user 188535]

Checked screen, it's clear. Piston and rings look brand new.

Warranty it.

 

[user 188535]

6 months old? Stihl's problem. DO NOT disassemble.

I'm kind of late, but he is right.

 

[buzz sawyer]

Going deeper, the cold compression is about 135. Should be enough to start.

As with some other posts, I can't get a pop. Pulled plug, turned it upside down and out came maybe an ounce of premix. I'll air it out overnight and try again tomorrow.

Did read a post where an old guy lightly preheats his plug tip with a torch, squirts in some carb cleaner with good success.

Will update tomorrow, but that 4mm max gap on the spark tester still seems on the low side.

I have a 170, 180, 211 and using the correct comp tester (shrader valve in the end that screws into the plug hole), The most I can get is 135 and they all start and run fine. Sounds like yours is flooded. Make sure the choke is closing completely. I've read about problems with linkage that doesn't let the choke close fully.

 

[etbrown4]

Sawyer was exactly right. The factory setting on the choke left it slightly open when closed. I tweaked the linkage and got it to close. Starts perfect.

It's odd to me that Stihls quality checks did not catch this. These saws are made in Va Beach, Va, and you would think they could do better.

 

[Eman85]

It's odd to me that Stihls quality checks did not catch this. These saws are made in Va Beach, Va, and you would think they could do better.

????? Why is VA Beach drawing from different labor pool hen the rest of the country? Made in USA means nothing, most factory workers can't pass a drug test or just don't care about what they are doing.

 

[etbrown4]

Don't want to hijack my own thread getting into Usa vs China made. The real story here is this choke on my saw and apparently lots of others have been set incorrectly at the factory. Their QC failed.

I guess the real point is the Stihl company failed to supervise their own workers, regardless of the location. Many of us might like to think that made in the usa means it's better, but ultimately it is all about quality control.

 

[ZeroJunk]

Don't want to hijack my own thread getting into Usa vs China made. The real story here is this choke on my saw and apparently lots of others have been set incorrectly at the factory. Their QC failed.

I guess the real point is the Stihl company failed to supervise their own workers, regardless of the location. Many of us might like to think that made in the usa means it's better, but ultimately it is all about quality control.

I had one of those in a while back. The issue was actually with the carburetor and the way the choke butterfly was not aligned . Not that the problems are all the same.

 

[stihltech]

You would think I would see these issues daily with hundreds of these out there. But I don't. Actually have not had a choke issue with most saws in the last ten years. I do know that linkage needs to be assembled correctly.
And I have many Amish customers. Best torture test for a saw you can get.