Snowchaser
ArboristSite Operative
I would much rather rebuild and clean out a quality factory carb than chuck it and buy a chicom pos, but theres no fixing that factory carb.
Aggrevation with ms170 project
- Thread starter Mouthfulloflake
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Mouthfulloflake
ArboristSite Lurker
I gave away a ms250 project years ago ( melted case and oilpump) I wish now I had kept the carb
$30 isnt a huge deal I will probably order one.
Thanks guys!
$30 isnt a huge deal I will probably order one.
Thanks guys!
Well, the second part of my reply, where I said about the carb still needing cleaning still stands.
not the first time ive come across cheap chinga stuff that just dosent work, their carbs for example are real hit and miss, the ones I got were all miss, wouldnt hold tune, erratic running, poor starting etc, put rebuilt genuine one back on, and good as gold.
Same with their motors, some may be good, others just wont even start.
LordOfTheFlies
ArboristSite Lurker
One at a time, spray some brake cleaner around the 1) clutch 2) the intake manifold boot 3) base of the jug with the top cover off, and see which spot stalls it out. You could have an air leak somewhere.
I agree with Cookies. I have 2 170s and the carbs are very sensitive to blended ethanol fuel. Our fuel supply in KY is junk. jmho
OT
Husky77
ArboristSite Operative
170 always runs rich, most people cut firewood with them here in uk or as a garden saw so they may not see as much wide open throttle thus burning clean. I have repaired a good few of these and all has been run on cheap oil and pump petrol. Very choked up with carbon. You cant tune them there are no high and low jets just a tick over adjustment which from memory is a left hand thread. If it were me I would upgrade to a better saw.
Mouthfulloflake
ArboristSite Lurker
I have a slew of other saws, just trying to get this one running thanks.
you can get aftermarket carbs for under 20 bucks for the 170 that are fully adjustable with the majority saying it makes the little saws run much better.
Mouthfulloflake
ArboristSite Lurker
Been iced in here, fumbling around the shop I found a carb with a chinese rebuild kit that looked identicle to the factory MS170 carb.
installed it, put it all back together.
2 pulls and it kicked on choke, move the control lever one more pull and it lulls.
EXACT same issue ( wont rev)
at this point I am thinking that dang manifold rubber assembly must have been damaged during install.
I hate this saw, but im angry enough to make it work. haha
installed it, put it all back together.
2 pulls and it kicked on choke, move the control lever one more pull and it lulls.
EXACT same issue ( wont rev)
at this point I am thinking that dang manifold rubber assembly must have been damaged during install.
I hate this saw, but im angry enough to make it work. haha
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Take the original carb apart and put up a few pics of it.
Mouthfulloflake
ArboristSite Lurker
thats a great idea, will do in the next day or so!
Ahhh...the pinched tit. Always trouble!
Mouthfulloflake
ArboristSite Lurker
haha, I get smacked for pinching tits.
I was really careful , but now that im going through the bags of parts, I realize it was an aftermarket rubber intake manifold.
Ill order an actual one from STIHL if the local dealer can source it now. ( they have been iffy on parts for a year or more)
I should have just dropped $200 on a new tiny cheap saw that I dont really need.
hehe oh well.
I was really careful , but now that im going through the bags of parts, I realize it was an aftermarket rubber intake manifold.
Ill order an actual one from STIHL if the local dealer can source it now. ( they have been iffy on parts for a year or more)
I should have just dropped $200 on a new tiny cheap saw that I dont really need.
hehe oh well.
Stihl needs to leave the cheap homeowner saws to the Poulan and Homelites of the world.
if its carb related exhibiting that behavior its the impulse section not functioning properly or the diagram is hard/torn/ carb cover packed full of dust preventing proper travel. I have seen coils and plugs cause it too.
Mouthfulloflake
ArboristSite Lurker
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First place I would spray carb cleaner/ check for a leak is right here where the carb mates against the boot. With a cheap aftermarket boot, if the rubber flange isn't thick enough, the carb bottoms out on this plastic area before it seals against tight against the boot. Pretty common.
You said you cleaned the original carb, so I'm guessing the inlet screen is actually clean and it's just the picture making it look dark/dirty?
After WAY too many headaches over the years, I have absolutely zero faith in carbs made of chinesium. Work one day not the next, some never do, etc. Also, was the fuel line a genuine stihl part? I've found that the cheap Chinese molded fuel lines for Stihls are often inferior & too soft. They will actually bend/kink in the tank and even more likely near where it hooks onto the nipple on the carb.
Sometimes it's the most simple things too. Have you tried changing spark plugs? I've had a run of garbage plugs the past few years, all I run is NGK. They'll look just fine, have decent spark, & have me chasing "fuel issues." I'll change the plug and bam, perfectly running saw.
You said you cleaned the original carb, so I'm guessing the inlet screen is actually clean and it's just the picture making it look dark/dirty?
After WAY too many headaches over the years, I have absolutely zero faith in carbs made of chinesium. Work one day not the next, some never do, etc. Also, was the fuel line a genuine stihl part? I've found that the cheap Chinese molded fuel lines for Stihls are often inferior & too soft. They will actually bend/kink in the tank and even more likely near where it hooks onto the nipple on the carb.
Sometimes it's the most simple things too. Have you tried changing spark plugs? I've had a run of garbage plugs the past few years, all I run is NGK. They'll look just fine, have decent spark, & have me chasing "fuel issues." I'll change the plug and bam, perfectly running saw.
These cheap little saws can be so frustrating, but once they're properly dialed in, they are super handy! I know one can't keep "throwing hundreds" into a saw worth $40, but I have swapped genuine Walbro WT-215 carbs onto many a problem child ms170/180 with nothing but wonderful results. My .02
Procedure for fixing the ms170.
1. Throw across yard.
2. Replace all AM parts with OEM.
3. Swear at saw.
4. Haunting nightmares.
5. Your going to give up and it runs.
6. Sell as fast as possible.
1. Throw across yard.
2. Replace all AM parts with OEM.
3. Swear at saw.
4. Haunting nightmares.
5. Your going to give up and it runs.
6. Sell as fast as possible.
Make sure the hi speed jet is clean and inlet lever is correct height. 75 % of running problems are cured there.
