Poulan 2000 issue

[jerrycmorrow]

So I have an issue I’ve never encountered. Parts of the symptoms I have but not as this is encountered
Compression is 100 psi. Tunes well and starts and runs good BUT it sometimes runs like it’s really lean. Flat runs like I’ve got throttle fully depressed but not so.
I tested for compression and vacuum leaks. Holds 14 psi vacuum for a couple minutes or more but won’t hold pressure. I tested for pressure leak by dunking in water. The only leak is through the oiler vent by the bar oiler (vent is a small hole with what looks like a cotter pin in it). Seals are good.
So anybody got idea of what gives?

 

[J D]

Oil pump is driven by crankcase pressure through a duckbill valve. Your air is leaking out the relief vent. To pressure test, try it with the oil reservoir full &/or cover the vent with some grease & put your finger on it. If it holds vacuum there shouldn't be any issues in that department anyways.
Does it oil properly?
Have you checked fuel lines, filters, vents, carb, etc?

 

[redunshee]

What JD said. Countervibes are similar though there is no duckbill. Comp seems a bit low but dont have first hand exp. with a 2000.

 

[lone wolf]

So I have an issue I’ve never encountered. Parts of the symptoms I have but not as this is encountered
Compression is 100 psi. Tunes well and starts and runs good BUT it sometimes runs like it’s really lean. Flat runs like I’ve got throttle fully depressed but not so.
I tested for compression and vacuum leaks. Holds 14 psi vacuum for a couple minutes or more but won’t hold pressure. I tested for pressure leak by dunking in water. The only leak is through the oiler vent by the bar oiler (vent is a small hole with what looks like a cotter pin in it). Seals are good.
So anybody got idea of what gives?

Also100 lbs compression is low! Are you pulling the pull starter till the gauge stops rising or stopping at a fixed number of pulls? What did the piston look like with the muffler off?
If you have an actual air leak then that could cause a scored piston thus low compression,check that leak thouroughy.

 

[jerrycmorrow]

Also100 lbs compression is low! Are you pulling the pull starter till the gauge stops rising or stopping at a fixed number of pulls? What did the piston look like with the muffler off?
If you have an actual air leak then that could cause a scored piston thus low compression,check that leak thouroughy.

yeah i agree its low. definitely pulling beyond when the gauge stops reflecting higher value. piston looks good through the exhaust port. gonna split the case to check everything out.

 

[dando127]

the 2000 I had had an air leak caused by screws that were too long in the carb/air filter cover. I'm not sure what they were pushing on. Make sure you are using short screws in that cover.

 

[jerrycmorrow]

Split the case tonight. Looks like some previous Richard cranium took a short try to split it with a screwdriver. Not extensive gouges but enough I’m gonna have to get some glass and fine sandpaper. Will let you know

 

[RedneckChainsawRepair]

Split the case tonight. Looks like some previous Richard cranium took a short try to split it with a screwdriver. Not extensive gouges but enough I’m gonna have to get some glass and fine sandpaper. Will let you know

If split I just use Threebond 1194 1184. But the part number OEM is for ultra black.