have a stihl ms290 that I put the drop in 390 modified muffler did leak test had a leak re sealed with dirko now my idle screw doesn't adjust or effect revs when I turn it, can any one tell me whats wrong?
How was it running before you started "improving" it?
If saw is reving fast at idle, could be an air leak. I had one where I didn't get the clamshell sealed well, so it leaked at the cylinder base. Look at the long bolts that go thru: Housing - Clamshell - Cylinder. See if black fuel is oozing out.
no black around cylinder to pan but is black when I took muffler off there was a lot I look up parts for the ms290 and it shows 2 gaskets one metal when I purchased new gasket I was given just the metal one thxs for reply this saw is driving me bonkers
pnwrusty I couldn't keep it running found a leak resealed with dirko no leak,did put in 6mm cap head screws with nuts due to overtightening self screw, adjustment on low effected rpms but the idle screw has no effect, not sure if this answers your reply
If there is no air leak and saw revs up fine with throttle...may be idle screw to throttle linkage plate is wonky. Can you see the throttle link plate move when you turn the tapered screw in? If that checks out, I'd try a new carb. And double check there's no air leak.
adjustment on idle screw did move butterfly alittle, the oil seal was cockeyed on shaft stuck out about 1/8 on top and bottom where it suppose to be would this effect idle?
If crank seals aren't seated or have cracks, there is a bottom end air leak...saw will run lean and fast. Idle screw may not have much effect.
The oil seals have grooves that they must seat into. You can look at the 290 engine you took out and see how the seals seat.
took it apart and did the seals right, still have a problem with the muffler to cylinder leaking looked at a utube rebuild for the 390 and it shows two muffler gasket one is the metal the other nonmetal do you no how many? couldn't find it in parts
1127 149 0601 - large gasket against cylinder. (I call this a plate)
1127 149 0650 - small gasket against muffler.
thxs dougand3 for all the help, lastly got a chance to put it back together and dang I lost the carburetor adjustment rubber grommet do I need to buy another or can I do w/o it?
The grommet isn't absolutely essential, you can run for a while without it. But, it would be a good idea to go ahead and get one on order and you can install it later.
need to purchase a carb. baileys says its a 1127 120 0604 when I go to google I can get it for half price but instead of limiters the carb. has springs for h&l adjustment screws can u tell me if the cheaper carb will be okay to install
purchased new carb for the ms390 did tunning now the saw is using twice as much gas starts up and runs good, only able to cut log with g777 granberg mill for about 2 ft and out of gas does anyone know why?
Sounds crazy rich.
if the carb is set to too rich wouldn't I get a lot of smoke and bog down during cut which it isn't doing either
I'd think saw would run like a dog and smoke if so rich to notice increased fuel consumption. Bet you have a fuel leak somewhere - line coming out of tank, tank itself, connection to carb, fuel lines, purge bulb. Check all of them.
all new hoses, cannot see where its leaking at filled it up this morning same, no spots where I put it on top of white paper wood u verify this is the correct procedure for tunning new carb adjust idle till chain is rolling approx.3300rpm,low screw until max.rpm,idle screw until chain is barely moving ,low speed until max rpm idle speed until chain is not rolling high speed wide open screw out until it bubbles 4cycle then in just a minute I did modify muffler
once, my 066 spend a tank of fuel twice that fast as normal. needed new carb kit
just purchased a new carb from stihl and installed I hope that's not it!
why does my oil for chain is coming out on top of clutch cover? I turned the adjusting screw ccw all the way, oil still came out of the little hole
can someone tell me why my ms390 won't 4cycle, sputter, when I try to adjust the hspeed screw