I need your 2 stroke thoughts/help

[Travelover]

I have an old Stihl weed cutter with similar symptoms. I hit it with a shot of WD 40, which used propane as a propellant. The propane kicks it right off.

 

[JB4310]

I have an old Stihl weed cutter with similar symptoms. I hit it with a shot of WD 40, which used propane as a propellant. The propane kicks it right off.

Never thought of that before, I'm sure it's better than the ether for the engine too, with its lube properties.

JB.

 

[FastPauly]

I have said it before and I will say it again.....small 2 cycle engines are very sensitive to exhaust restriction. Take the muffler off and see if it will start O.K then. If so, do whatever is necessary to clean out the restriction...be it carbon build up or stuff the mud dauburs have deposited.

 

[JB4310]

I have said it before and I will say it again.....small 2 cycle engines are very sensitive to exhaust restriction. Take the muffler off and see if it will start O.K then. If so, do whatever is necessary to clean out the restriction...be it carbon build up or stuff the mud dauburs have deposited.

Yup, I've had the spark arrestor screens block up to the point of choking the exhaust.

JB

 

[thatguy]

I have said it before and I will say it again.....small 2 cycle engines are very sensitive to exhaust restriction. Take the muffler off and see if it will start O.K then. If so, do whatever is necessary to clean out the restriction...be it carbon build up or stuff the mud dauburs have deposited.

I did take the exhaust off and cleaned off a small mesh screen that was over the opening..

wouldnt any restriction also cause it to not run correctly? Once i get it started it runs good..


Brian

 

[FastPauly]

The restriction will affect starting the most....the carburetor cannot do its job on delivering enough fuel for a cold start. If measures are taken to force fuel into the cylinder chamber it may start and continue to run....but not to full potential.

If it can't freely move air out....it won't bring the proper air/fuel mix in.

 

[My Hoe]

If you can get to both sides of the crank, make sure you have ZERO RADIAL play in the crank. (Radial as in out in ANY direction that is 90 degrees to the orientation of the crank--not talking about END play here--some of that is okay).

The reason I say to check this is, I have a couple of chainsaws that have shot crank (main) bearings. This allows the cranks to "travel" and erode the seals around the crank.

On a 2-stroke, the crank seals MUST be **** near air-tight, as the incoming charge is typically routed UNDER the piston first, then up through "transfer ports" in the actual SIDEWALLS of the cylinder. The downstroke of the POWER STROKE actually "charges" or pushes the incoming charge into the combustion chamber, ABOVE the piston, via these transfer ports. (It's kind of like that back stairwell in your Grandpa's farmhouse that never got used much...except this is used constantly.)

If the crank seals are leaking, the incoming charge won't be driven up through the transfer ports with enough volume/force/whatever, to allow easy starting.

An old saw of mine, and one of my friend's, both have this problem. They'll start COLD, but not hot, as I guess the worn crank seals are more "cranky" by the time they're hot.

I know cold starting is not working for you either, but just check the crank bearings for "radial play" see.

Let us know?

My Hoe

 

[2manyrocks]

Cleaning a 2 stroke muffler isn't that difficult. You can't tell what's in the baffles inside unless you cut it apart, but you can take the whole thing off, and heat it up with a propane torch--(be sure there's no unburned gas in it first) and carbonize whatever deposits are in it. Then you let it cool and shake out the junk. That should get the muffler free flowing again.

I've got an old echo trimmer with a primer bulb. I never use the primer--just choke it once, and then it starts.