395 XP wont start

[roundhead]

I have been working on this for awhile now off and on. I have good compression, spark, and cannot find any leaks. it just wont fire. the spark is decent but not as strong as my 288. i have tried pouring a small amount of fuel in the cylinder and carb and it just wont pop. where should i start looking next? timing? new coil? I hate to give up but I'm stumped
thanks

 

[HuskStihl]

If you have good compression (on a gauge), and it won't even pop with fuel in the cylinder, I'd try a different coil

 

[decableguy2000]

Make sure your flywheel key isn't sheared and your timing is off.

Jeremy

 

[Chainsaw Jim]

A saw can still have a toasted piston and still pull 160lbs compression. Pull the muffler and check the piston. If it is clean then pull the carburetor and check that side of the piston if you can't peek though the carb to see it.
If the piston is good and the rings aren't stuck then it's likely time to put a new kit in the carb.

 

[Mattyo]

If you have comp and fuel....it's an ignition issue. Either coil...wire...plug or timing...a shorted grounding wire?

 

[rmh3481]

If your sure of the timing, sometimes the coil wont fire under compression. You can try a non Resistor plug and see if that will get you there. Try CJ6 instead of Rcj6 etc. The resistor in in the plug for air pollution reasons and wont spark unless the voltage is high enough. If your getting a bright blue spark on a tester then its likely not the ignition. If your getting a yellow orange spark it probably is the ignition.

 

[AVB]

IIf your getting a yellow orange spark it probably is the ignition.

Really depends on where you live. A spark can be this color and still be good. It the amount of sodium in the air that can cause a yellow/orange spark. Say you in Hawaii or any where salty air is common then yellow/orange is quite common. To determine spark strength a spark gap arc tool need to be used.

Also spark plugs and coils can be borderline bad and won't fire under compression due the increased electrical resistance.

 

[Rx7man]

If you've poured a little fuel down the carb, check to see if the plug is now wet.. if it isn't, pour a little more in, if it is, clean it off. If it fires after, check your fuel lines to the carb, a little pinhole in the line can cause all sorts of grief.. Some carbs have a plastic elbow on the fuel line that loves to crack.

What I do on some finnicky engines is I warm the head with a small propane torch for a minute or two, basically getting it to operating temperature, just move the torch around and heat evenly.

 

[rob066]

My friend brough me A husky 257 with a no start situation. It had good spark but would not start. replaced plug 2nd pull it started.

 

[Rx7man]

My friend brough me A husky 257 with a no start situation. It had good spark but would not start. replaced plug 2nd pull it started.

Thats just hearsay.. plugs never go bad

 

[rmh3481]

>>It the amount of sodium in the air that can cause a yellow/orange spark. Say you in Hawaii or any where salty air is common then yellow/orange is quite common. To determine spark strength a spark gap arc tool need to be used.<<

Quite interesting. Im glad you shared this because I had not heard this before. Thank you.