Help me out Stihl Bros. MS310

[Deets066]

The metering arm should be flush with the carb body on a walbro

 

[Fruecrue]

Just got up having muh morning coffee, I'll be heading to the bench in a little while. Good to know I already have a 390 top end. My friend has a 391 and I like the power it has.

Measuring the bore is the only way to know. 46mm, 47mm and 49mm are available aftermarket.

 

[XP_Slinger]

Measuring the bore is the only way to know. 46mm, 47mm and 49mm are available aftermarket.

Copy all. Gonna pressure check it and if it passes I won't be pulling the top end yet. I almost want to just to see what I have, but I'm not at this point.

 

[XP_Slinger]

What the hell does this spring clip on the oil pump drive do? It just spins, doesn't stop against anything.

 

[Fruecrue]

The slot in the clutch drum drives it, only oils when the clutch is engaged.

 

[Adamski]

Good to know. Mine was well above the carb body on initial tear down. I set it even and it helped. The pump diaphragm is rigid as all hell, no sag to it at all. Maybe it's ok but I've never seen one with out at least a little sag.

Mine got a fresh carb kit in it, only due to the fact that the codfish that I bought the saw off decided to hide the fact that the carb was in 'ill health' by screwing it all back together with nothing inside, metering lever and all was missing....

 

[BuckthornBonnie]

Mine got a fresh carb kit in it, only due to the fact that the codfish that I bought the saw off decided to hide the fact that the carb was in 'ill health' by screwing it all back together with nothing inside, metering lever and all was missing....

Lol that is funny... sorry to hear that, but still funny.

 

[XP_Slinger]

The slot in the clutch drum drives it, only oils when the clutch is engaged.

Makes sense, thanks. Just unfamiliar with the design and I like knowing.

 

[BuckthornBonnie]

Kinda dirty back there for a fairly fresh rebuild. I hate when shops don't clean that area on clamshell rebuilds. I do suppose a little run time could do it, tho.

 

[XP_Slinger]

Pulse line leaked on the pressure test, put a zip tie on it and it held. Checked crank seals once the pulse line was good and they ain't leaking a damn bit. Think I found my problem in the back tracking process. Commenced to turning the jets in on the carb to see how many turns they were out. Noticed that the low speed jet was wobbling on its way in. Pulled it out and behold the bent jet body. I believe this is problem because it can't thread all the way into the bottom due to the bend. Explains fuel spitting, low side is super rich. Damage most likely occurred when someone deleted the limiters. Didn't notice the wobble with the saw running for obvious reasons.

 

[XP_Slinger]

Re-assembly in progress. Gonna try to gently bend the jet straight to verify the problem. If it breaks (likely) I'll get another carb. Found the intake clamp bad too, slight bend to the screw and partially stripped nut that can't get past the bend. This saw is just bent...lol!

 

[Dub11]

Re-assembly in progress. Gonna try to gently bend the jet straight to verify the problem. If it breaks (likely) I'll get another carb. Found the intake clamp bad too, slight bend to the screw and partially stripped nut that can't get past the bend. This saw is just bent...lol!

Not the saw just the last fool to work on it.

 

[Terry Syd]

Sounds like your saw was worked on by a moron like mine. Crikey, I had SAE bolts stuck into metric threads, a loose bar that wallowed out the cases, no tank vent, a loose coil against the flywheel that wore a groove, only three bolts holding the jug on (with an air leak), seized piston, worn out air filter with no felt (obviously scrubbed clean by the moron), lost bolts and spacers, a chainbrake that didn't work because of the re-assembly, an oiler that didn't work because the clutch had been jammed on - and a bunch of other stuff I don't want to remember as I had to spend time fixing up his dumb-ass mechanical 'repairs'. Some people shouldn't even be allowed to pick up a wrench.

The saw works great now - it's my go-to saw.

 

[Adamski]

The saw works great now - it's my go-to saw.

What other saws do you have? I am soo intrigued to get this clam shell cutting wood this weekend to see how it fares..

 

[Fruecrue]

I had one so bad once I was actually worried about sharing the road with the guy ( bought in my town), because you just know he is doing the same hokey chit on his vehicles.

 

[Terry Syd]

I've got a 50cc 450 Husky that I did a heap of work to. The transfer work took weeks, it is running the equivalent of a 19mm carburetor - the powerhead weighs 11.8 lbs and is running a lightweight NK bar. The damn thing surprises me every time I pick it up to use, so light and cuts so fast. It just doesn't have the extra grunt I need for bucking some of the big Ozzie hardwood I cut, but for limbing up to 16-18" it is a nice nimble saw. Usually running an 8-pin and 18" bar.

The other saw is a Chinese clone 365 with a 77cc big bore that has been ported to flow like a 77cc saw. It has a modded Zama on it and supports a 24" bar running an 8-pin. It is my bucking saw, heaps of torque and just won't stop.

The 64cc 029 sits in between the two saws. It was suppose to be a 'loaner saw', but after tweaking it a bit (homemade air filter, advanced timing, modded carb) and putting on a 20" lightweight NK bar, I tend to use it for most cutting. The 20" bar has a good reach for limbing and is very light and nicely balanced. Although it is running an 8-pin, I use it to buck up logs up to 24". I really should use the 77cc saw for the bigger wood, but I like the light weight of the modded 029. I needed to put dual dawgs on it to help keep the cuts straight on the bigger wood.

 

[Adamski]

I've got a 50cc 450 Husky that I did a heap of work to. The transfer work took weeks, it is running the equivalent of a 19mm carburetor - the powerhead weighs 11.8 lbs and is running a lightweight NK bar. The damn thing surprises me every time I pick it up to use, so light and cuts so fast. It just doesn't have the extra grunt I need for bucking some of the big Ozzie hardwood I cut, but for limbing up to 16-18" it is a nice nimble saw. Usually running an 8-pin and 18" bar.

The other saw is a Chinese clone 365 with a 77cc big bore that has been ported to flow like a 77cc saw. It has a modded Zama on it and supports a 24" bar running an 8-pin. It is my bucking saw, heaps of torque and just won't stop.

The 64cc 029 sits in between the two saws. It was suppose to be a 'loaner saw', but after tweaking it a bit (homemade air filter, advanced timing, modded carb) and putting on a 20" NK bar, I tend to use it for most cutting. The 20" bar has a good reach for limbing and is very light and nicely balanced. Although it is running an 8-pin, I use it to buck up logs up to 24". I really should use the 77cc saw for the bigger wood, but I like the light weight of the modded 029.

hmm, I am intrigued to see how this ms390 goes next to my 372xp.

I used to have a Jonsered 2150, which was the same as the 350, superseded by the 450. That saw was a little hornet, mine was 50ccx, base delete and modded muffler, timing advanced a wee 4 degrees. It was immense for a little 50cc clam shell. I liked the way it had a riser allowing for the gasket delete like a pro line.

Those china 365/372's by all accounts run good with a little tinkering My 372xp has a meteor kit on it, although the piston's are still cast and finished in Italy I think the meteor cylinders are cast in China and nikasil plated in Italy. I am a fan of china parts, particularly Farmertec they are trying to compete and some of the stuff is top notch.

 

[XP_Slinger]

hmm, I am intrigued to see how this ms390 goes next to my 372xp.

I used to have a Jonsered 2150, which was the same as the 350, superseded by the 450. That saw was a little hornet, mine was 50ccx, base delete and modded muffler, timing advanced a wee 4 degrees. It was immense for a little 50cc clam shell. I liked the way it had a riser allowing for the gasket delete like a pro line.

Those china 365/372's by all accounts run good with a little tinkering My 372xp has a meteor kit on it, although the piston's are still cast and finished in Italy I think the meteor cylinders are cast in China and nikasil plated in Italy. I am a fan of china parts, particularly Farmertec they are trying to compete and some of the stuff is top notch.

I wouldn't expect the 390 to run near the 372 in wood 20" and up. Under that they'll probably be close.

 

[XP_Slinger]

Buttoned the 310 back up and it's still running like poop. Not that I expected anything different, I almost got it to idle but I had to back the low speed out like 4.5 turns to get close to an idle. Took the carb back off to raise the metering lever a touch hoping to get more fuel to it and now the dern thing will only fire for 2 seconds. Pressure checked the fuel line, no holes. That carb is fooked.

 

[dall]

Get a 044 carb for it