Stihl 044 hard start warm

[cpeltier]

I have a 24 year old Stihl 044 which is my preferred saw. It is well used and I have two bar sizes that I use. I am on my third set which give you an idea of the hours on the saw.
Recently it has become difficult to start when warm. If I let it sit it starts right up. If I pull the cord like a crazy man when warm I can get it to start. Once running it runs fine with plenty of power.
The compression is 135 PSI with an auto style gauge (longer hose) which seems ok.

I've looked around and found that it could use a carburetor rebuild. I've also read it could be a magneto issue. There appear to be several different carbs available for this saw so I can't just order an overhaul kit without taking it all apart to identify the version I have. I'm told by Stihl that the serial number does not identify the carburetor version.

Does anybody have any experience with this type of problem?

 

[Jon1270]

If it were an ignition problem then pulling the heck out of the starter wouldn't help.

135 compression is getting low, and the length of the hose shouldn't matter, but compression gauges are often inaccurate so I wouldn't depend on that reading unless you can confirm it with another known-good gauge.

A carb rebuild is easy and cheap, so it's a good place to start. Pull the air filter, remove the two 8mm nuts behind it, remove the plastic air filter backer plate, disconnect the throttle linkage and pull the carb out. Look for markings on the carb, and order the right kit via eBay (unless you like overpaying, in which case order from the dealer). While waiting for the kit, buy a can of aerosol carb cleaner.

 

[Fifelaker]

If you suspect your compression is that low, pull the muffler and look at the piston and cylinder. 135# is low for that saw. If you do have something going on and keep running it, it can ruin the cylinder as opposed to a set of rings. Another thing is a dab of two stroke oil in the cylinder when it is warm. If it starts right up you have compression issues. By the sounds of things mother Stihl figured out they were losing money to the aftermarket suppliers so they dropped the price on their pistons and stuff. I would not hesitate to put caber rings or a meteor piston in it though.

 

[cpeltier]

Thanks for the responses! I did pull the muffler off and took a peak. There is no scoring and the surfaces are smooth and shiny.It looks like new.

It won't hurt to do the carburetor overhaul so I'll start there. I'll also try the oil trick.

 

[Clarkbug]

If you put it back together, run it some, and then shut it down, try to open the fuel cap. Then try to start. If your tank vent is plugged, it could be creating a vacuum. But after 24 years a carb rebuild, and new fuel line, filter, and maybe impulse line wouldnt hurt.

 

[Adios Pantalones]

I thought fuel cap as well (looking at cheapest first), but that would also cause it to stall. Is it stalling? I assume you've done a simple carb adjust on it?

 

[CountryBoy19]

135 compression is getting low, and the length of the hose shouldn't matter, but compression gauges are often inaccurate so I wouldn't depend on that reading unless you can confirm it with another known-good gauge.

Some cheap compression gauges (especially for automotive purposes) don't have a Schrader valve at the tip of the hose, and therefore the hose adds volume to the combustion chamber, artificially lowering the compression reading. The compression may be normal but for a small-displacement engine this added volume in the hose can make a drastic change to the compression reading...

 

[Jon1270]

Some cheap compression gauges (especially for automotive purposes) don't have a Schrader valve at the tip of the hose, and therefore the hose adds volume to the combustion chamber, artificially lowering the compression reading. The compression may be normal but for a small-displacement engine this added volume in the hose can make a drastic change to the compression reading...

Yes, the valve at the tip can make a big difference. Hose length should only affect the number of pulls it takes to get a meaningful reading.

 

[Jon1270]

I thought fuel cap as well (looking at cheapest first), but that would also cause it to stall. Is it stalling? I assume you've done a simple carb adjust on it?

It's not a vented fuel cap; it can't fail in the way you're thinking.

 

[Adios Pantalones]

I meant tank vent (I assume it has one). Anyway- unless it is stalling, it would be unlikely.

 

[Jon1270]

Ah, yeah, that could be. I replaced one of those just yesterday, but because the check valve in it had failed and stuck open, not closed, so it was leaking fuel, not starving the motor.

 

[CountryBoy19]

Yes, the valve at the tip can make a big difference. Hose length should only affect the number of pulls it takes to get a meaningful reading.

Schrader valve at the tip of the hose will mean it takes more pulls to reach the true reading; longer the hose, the more pulls.

Schrader valve somewhere after the hose, but before the gage unit will NEVER give the true reading no matter how many times you pull because the hose itself is altering the volume of the head and therefore it will build less compression.

 

[Clarkbug]

I meant tank vent (I assume it has one). Anyway- unless it is stalling, it would be unlikely.

My thought was that if its partially plugged, it could create a slight vacuum in the tank. When running the carb can still pump fuel, but once its turned off it can't overcome the vacuum in the tank until it equalizes itself.

Other option could be ignition related, so its also worth pulling the plug when its hot and not starting to see if you still have spark.

But the carb is a good place to start after that many years anyway...

 

[cityboy172]

My ms460 had that problem for a while...

 

[Ashful]

I have a 24 year old Stihl 044 which is my preferred saw. It is well used and I have two bar sizes that I use. I am on my third set which give you an idea of the hours on the saw.
Recently it has become difficult to start when warm. If I let it sit it starts right up. If I pull the cord like a crazy man when warm I can get it to start. Once running it runs fine with plenty of power.
The compression is 135 PSI with an auto style gauge (longer hose) which seems ok.

I've looked around and found that it could use a carburetor rebuild. I've also read it could be a magneto issue. There appear to be several different carbs available for this saw so I can't just order an overhaul kit without taking it all apart to identify the version I have. I'm told by Stihl that the serial number does not identify the carburetor version.

Does anybody have any experience with this type of problem?

I see you're in Telford. Take it to Penn Holo over in Skippack. They'll have you fixed up.

 

[cpeltier]

I have yet to make my next move. I'm in no immediate rush but I have plenty to cut before it gets too hot in the summer.

My compression gauge does have the check valve at the end of the hose so it does add the volume of the hose to the cylinder displacement in effect lowering the perceived compression.
I'm thinking my compression is probably ok unless it does lower when warm.

I'll do the overhaul items as described here and see what happens. I'm 15 minutes from Penn Holo (get my Bandit chipper blades there) which would be a last resort.

Thanks for the help!