Help me out Stihl Bros. MS310

[BuckthornBonnie]

Beware of some am carbs for this series. Others work ok, but I have one that you can't lean the H enough to get it right. It runs and idles so I use it as a test carb.

 

[BuckthornBonnie]

Fuel coming out muffler? Probably carb. Rarely coil but it could be bad.

 

[XP_Slinger]

Fuel coming out muffler? Probably carb. Rarely coil but it could be bad.

I had the coil thought myself, but it was spitting fuel out the muffler so I drew the same conclusion that you suggested.

 

[Adamski]

Any progress, had the ms390 working for the first time this weekend. I was really surprised. Bang for buck these 390's are snappy decent saws IMO. This is it in all it's glory. Just gotta find a more decent bar...

 

[XP_Slinger]

Any progress, had the ms390 working for the first time this weekend. I was really surprised. Bang for buck these 390's are snappy decent saws IMO. This is it in all it's glory. Just gotta find a more decent bar...View attachment 71073

Looks great! Glad you feel it was worth all your effort.

Haven't had time to tinker with my saw, I've been working on my vehicles and tomorrow I'm summarizing my boats. I'm going to order a carb kit today and cross my fingers. I'm hoping to find crud under a welsh plug or something. If the kit doesn't fix the problems it will be on hold for a while. Gotta pinch my pennies with vacation just around the corner.

 

[countryhog]

Bump

 

[countryhog]

Get a 044 carb for it

Got the subject saw fromXP_Slinger on the Christmas thread.
Wondering whats the difference between the MS310 (walbro hd 19?) and the 044 (walbro hd 16?) carbs as far as orifice size etc. Since probly gonna have to buy one i just as soon get the higher capacity one. Just sayin

 

[countryhog]

Measured bore with flat stick thrugh the exhaust port and comes out to 1.858” = 47.2 mm
Not sure how that squares with the presence of the decompression port. Just sayin
Opened fuel tank and line was barely holding on. Pressure tested by dunking and flywheel seal was leaking.
Got seals, carb kit, and fuel line ordered. Onward and upward

 

[countryhog]

What I will say is that this 390 with a muffler mod, advanced timing and matching the piston window to the cylinder transfers has made what looks to be a loud, loud screamer. It is also very very snappy with it's throttle response.. Just need to actually tune it in the cut at the weekend.

Reopening this thread cause finally working on the saw and have questions
Regarding matching the piston windows to the transfers - huh? Please edumacate me in graphic detail if possible. Thus far all ive ever done has been straight repairs and muff mods. Heres pic of piston.

 

[countryhog]

Got the subject saw fromXP_Slinger on the Christmas thread.
Wondering whats the difference between the MS310 (walbro hd 19?) and the 044 (walbro hd 16?) carbs as far as orifice size etc. Since probly gonna have to buy one i just as soon get the higher capacity one. Just sayin

Bump

 

[countryhog]

Never mind. Unintentional reply

 

[huskihl]

Bump

Last I remember, the 044 carb has about a millimeter bigger venturi than the 029 or ms310 carburetors

 

[countryhog]

Last I remember, the 044 carb has about a millimeter bigger venturi than the 029 or ms310 carburetors

Does it match the intale? Remember, this is my first stihl so be gentle

 

[huskihl]

Does it match the intale? Remember, this is my first stihl so be gentle

If not, it's real close. It's been a few years

 

[Terry Syd]

Last I remember, the 044 carb has about a millimeter bigger venturi than the 029 or ms310 carburetors

The size of the venturi is less relevant than the jetting. The 044 carb is a pre-EPA carb that is jetted for a 70cc engine. The 020-039 carb is an EPA compromised carb (it can be fixed) that is used on 54-64cc engines.

Also, the 'bottle neck' in the intake system is not the carb, it is the air filter. A quick fix is to get the nylon mesh filter. Now the engine can breathe - and as has been shown on this site, makes a significant difference in the power.

 

[isaaccarlson]

A 390 jug will bolt right on. Port the intake/exhaust, do a muffler mod, and run it. Mine runs 100% stronger now and pulls a 28” bar like cake. I had to mod my oiler.....

A word to the wise: widen the top of the intake and leave the bottom stock or you will get spitback. The duration on these is crazy long.

 

[countryhog]

Well guys. Got all parts and put it on bench for reassembly. Ptting the flywheel on and dont even get the nut run all the way down when the threaded end twists off. The end of the crank doesnt even clear the nut. Dam!
Anyone got a 310 crank theyd let go? Cheap?

 

[countryhog]

Bought crank on ebay. Had no idea they were so plentiful and telatively inexpensive. Do these cranks have a history of twisting off?

 

[67L36Driver]

Bought crank on ebay. Had no idea they were so plentiful and telatively inexpensive. Do these cranks have a history of twisting off?

This last MS 310 engine I had here was that way. A crank from Definative Dave plus bearings and seals, slap it in a chassis and sold it for three Benjamins. [emoji108]

Someone had twisted it off trying to remove clutch the wrong direction.

 

[countryhog]

@XP_Slinger
Finally got off my duff and put this thing together. As mentioned earlier in thread i installed new seals, fuel line, filter, and crank assmbly. Cleaned carb but tried it with same kit.
Filled with fuel and started on 8th pull. Gotta get tuned in and chain sharpened but im thinking i once again almost done. Thanks everyone for input. Only took a year. LOL
Merry Christmas to ya’ll.