I like to see them closer to 150.
Stihl 261cm, I need some help!
- Thread starter Stihlproincky
- Start date
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All this worry about compression numbers. Did it hold up by the starter handle? Does it spin over when pulled? Spark?What does the piston look like? Does it hold vacuum and pressure? Crank shaft play?
These are the things that matter when diagnosing. First and foremost- Is the fuel clean?Very few compression gauges used in a repair shop for 2 stroke. Internal condition is the most important!
Yeah I know, nobody wants to hear it.
These are the things that matter when diagnosing. First and foremost- Is the fuel clean?Very few compression gauges used in a repair shop for 2 stroke. Internal condition is the most important!
Yeah I know, nobody wants to hear it.
Speak about your own shop. Many mfg of 2 stroke engines ask for compression readings across cylinders as part of diagnostics. Just because most are too cheap to buy a quality gauge that works with small engines does not mean it's not a viable diagnostic tool.
Yes it's holds up by the starter handle, yes it spins, yes it sparks, piston is new oem, passed vac/pressure test, no crankshaft play, all is smooth as it should be.
Got the compression tester ( mityvac MV5520, thanks @huskydave) did a test came in at 150psi three times in a row. Passed vac and pressure test. Now I tried starting it and it floods out, won't even try to start. Anyone have a suggestion on when to look from here?
Took the plug out and now waiting on it to dry. Thanks everyone for the input and patience.
Took the plug out and now waiting on it to dry. Thanks everyone for the input and patience.
huskydave
Addicted to ArboristSite
I follow the shop manual and use the test procedures it outlines. I don't know too many mechanics who don't use a comp tester on a regular basis.
150PSI is good. Is the choke working properly? thinking it might be stuck on. If its flooded make sure the choke is off and hold the throttle wide open and start it like this, if it starts let go of the throttle and see if it will idle.
It might flood because the plug is fouled, wire brush it cleans an and blow off with air or replace.
Actually tried putting a plug from my saw in it that was almost new, yes it's the correct plug. That didn't change anything.
Take the air filter off and hold it wide open and pull the hell out of it and report back.
Ha.. I tried that already, but I'll try again.
Flywheel key sheared?
It is, it's lined up. I put a mark on it like you suggested.
Not a saw, but a handheld blower with a sheared key. Last week. Did it as described. Marked it with a Sharpie. Ran fine.
If you have compression and fuel, and it won't hit, your timing is off somehow I would think.
If you have compression and fuel, and it won't hit, your timing is off somehow I would think.
Of course this has been triple checked, right?
huskydave
Addicted to ArboristSite
do you have a spare coil to try? The flywheel should fire properly if its within a few degrees of where it is supposed to be located.
OK, I checked it again. Guess what? It was off, so I realigned it a it will try to start but the flywheel slips and of course messes with the timing. Is there anyway to fix this short of a new one?
Flywheel moves 1/4-1/2 of a turn, so I think that's the issue. thanks for the replie, I'll keep it in mind.
huskydave
Addicted to ArboristSite
can you take a pic of the crank? I would put a key in it if possible.
Attachments
Working on the key.
