Joined here in 2018 after having some problems & questions about my MS290, and got a lot of great info & help form Harley & a few others. Also learned a lot about the AM carbs for these, but learned the hard way by Trial & Error before find out so much about them here & the pit falls of buying after market parts.
This saw was difficult to start from the day I got it home, but it ran well once you got it started. I ended up having to reset the coil gap, and that cured my starting problem once I mastered the art required by STIHL, or recognizing the "burp" on initial pull and flipping the lever to 1/2 choke, & I got a lot of use from it over the next several years, & then it began running badly and I just could not get it set right.
Having said that, I checked compression which is at 143 consistently, then tested engine for Pressure/Vacuum, which it passed, by holding almost 8 lbs. with no leak down at all. So, I figure the only thing left to do was try replacing the carb, so I just purchased an OEM STIHL 1127-120-0604 HD-18D Carb, as it is listed in the Parts Info passed on to me thru this site, as 1 of 3 carbs listed for this saw.
It is my understanding from both this forum & from what I can see in the STIHL Manuals, that the 029/MS290 are basically the same, MS310, and 039/MS390 are basically the same, and that all 5 Models have a lot of interchangeable parts for certain things, but I am confused by the Carb numbering specs.
I purchased the STIHL 1127-120-0604 HD-18D as a replacement, because it is 1 of 3 spec'd out by STIHL as a Replacement.
The original I took off the 290, (see photos) is an HD-18C 1127-120- ????. It is stamped as 18C on the casting, but I do not see a Reference on any of the Specs listed as to letters C or D or anything else.
I also see that the 06o5 is only listed for the MS310, and no part number is given as a substitute for it, but it can also come with a HD-21 1127-120-0605, with no substitute number given for that either, YET the other 4 Models get an HD-19 1127-120-0650 listed as a substitute for the other numbered carbs.
STIHL Carburetor Reference Charts & Kits For Chain Saws
Model # Carburetor Model Carburetor # Substitute
029/MS290 HD-5 1127 120 0601 1127-120-0650
HD-18 1127 120 0604 1127-120-0650
HD-19 1127 120 0650 1127-120-0650
MS310 HD-19 1127 120 0650 No # Given
HD-21 1127 120 0605 No # Given
039/MS390 HD-5 1127 120 0601 1127 120 0650
HD-19 1127 120 0650 No # Given
HD-21 1127 120 0605 No # Given
So, I have some questions regarding these carburetors and the way they are Spec'd out:
1) Where the 1127-120-0650 is given as a SUBSTITUTE Carb for the HD-5 0601, HD-18 0604, is the 0650
an HD-02, or an HD-18 or an HD-19 ?
2) What is the designation HD-X or HD-XX and what is the reasoning behind that, and Where does the designation C or D come into play and what is that about?
3) Can an 1127-120-0605 ONLY be replaced with a 1127-120-0605 because of the HD-21 designation, or can any of the other ones be used?
Lastly & my most important question: Are these Carbs somewhat Pre-Set from the factory so after bolting them on, the saw SHOULD start, and then be fine tuned for best running, or is it a crap shoot right out of the box?
This saw was difficult to start from the day I got it home, but it ran well once you got it started. I ended up having to reset the coil gap, and that cured my starting problem once I mastered the art required by STIHL, or recognizing the "burp" on initial pull and flipping the lever to 1/2 choke, & I got a lot of use from it over the next several years, & then it began running badly and I just could not get it set right.
Having said that, I checked compression which is at 143 consistently, then tested engine for Pressure/Vacuum, which it passed, by holding almost 8 lbs. with no leak down at all. So, I figure the only thing left to do was try replacing the carb, so I just purchased an OEM STIHL 1127-120-0604 HD-18D Carb, as it is listed in the Parts Info passed on to me thru this site, as 1 of 3 carbs listed for this saw.
It is my understanding from both this forum & from what I can see in the STIHL Manuals, that the 029/MS290 are basically the same, MS310, and 039/MS390 are basically the same, and that all 5 Models have a lot of interchangeable parts for certain things, but I am confused by the Carb numbering specs.
I purchased the STIHL 1127-120-0604 HD-18D as a replacement, because it is 1 of 3 spec'd out by STIHL as a Replacement.
The original I took off the 290, (see photos) is an HD-18C 1127-120- ????. It is stamped as 18C on the casting, but I do not see a Reference on any of the Specs listed as to letters C or D or anything else.
I also see that the 06o5 is only listed for the MS310, and no part number is given as a substitute for it, but it can also come with a HD-21 1127-120-0605, with no substitute number given for that either, YET the other 4 Models get an HD-19 1127-120-0650 listed as a substitute for the other numbered carbs.
STIHL Carburetor Reference Charts & Kits For Chain Saws
Model # Carburetor Model Carburetor # Substitute
029/MS290 HD-5 1127 120 0601 1127-120-0650
HD-18 1127 120 0604 1127-120-0650
HD-19 1127 120 0650 1127-120-0650
MS310 HD-19 1127 120 0650 No # Given
HD-21 1127 120 0605 No # Given
039/MS390 HD-5 1127 120 0601 1127 120 0650
HD-19 1127 120 0650 No # Given
HD-21 1127 120 0605 No # Given
So, I have some questions regarding these carburetors and the way they are Spec'd out:
1) Where the 1127-120-0650 is given as a SUBSTITUTE Carb for the HD-5 0601, HD-18 0604, is the 0650
an HD-02, or an HD-18 or an HD-19 ?
2) What is the designation HD-X or HD-XX and what is the reasoning behind that, and Where does the designation C or D come into play and what is that about?
3) Can an 1127-120-0605 ONLY be replaced with a 1127-120-0605 because of the HD-21 designation, or can any of the other ones be used?
Lastly & my most important question: Are these Carbs somewhat Pre-Set from the factory so after bolting them on, the saw SHOULD start, and then be fine tuned for best running, or is it a crap shoot right out of the box?