How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Curtis B. Your Own Question
Curtis B.
Curtis B., Technician
Category: Small Engine
Satisfied Customers: 26026
Experience:  have worked on and around most engine models for 35 yrs./Polaris ATV expert
30244710
Type Your Small Engine Question Here...
Curtis B. is online now
A new question is answered every 9 seconds

Stihl ts400 has cmpession spark new carb gas .pops but will

Customer Question

stihl ts400 has cmpession spark new carb gas .pops but will not start.
Submitted: 1 year ago.
Category: Small Engine
Customer: replied 1 year ago.
has new ignition module
Expert:  Curtis B. replied 1 year ago.

What is compression?Needs to be 150 psi.

Customer: replied 1 year ago.
110psi
Expert:  Curtis B. replied 1 year ago.

When did it last run? If you put fuel direct into the cylinder, will it fire?

Customer: replied 1 year ago.
ran weekly . sometimes
Expert:  Curtis B. replied 1 year ago.

Fuel lines all been checked or replaced?

Expert:  Curtis B. replied 1 year ago.

Exhaust been cleaned?

Expert:  Curtis B. replied 1 year ago.

If all check out, I think you will find the piston scarred, remove the exhuast and look at the piston.

Customer: replied 1 year ago.
removed muffler blew it out . fuel lines have not been replaced
Expert:  Curtis B. replied 1 year ago.

did you look at the piston when exhaust was off?

Customer: replied 1 year ago.
will remve exhaust and inspect piston and get back to you.
Expert:  Curtis B. replied 1 year ago.

Ok, thanks.

Expert:  Curtis B. replied 1 year ago.

See if the rings have tension, you can push on them with scewdriver/

Customer: replied 1 year ago.
rings are free-compression is 120psi-fuel lines are clear-very minor cylinder scarring-cleaned exhaust with brake clean .pops 5or6 times than dies
Expert:  Curtis B. replied 1 year ago.

Do you have model with the compression release?

Expert:  Curtis B. replied 1 year ago.

Could it be leaking?

Expert:  Curtis B. replied 1 year ago.

Fuel lines correct?

Customer: replied 1 year ago.
fuel lines correct-removed compression release and plugged port
Expert:  Curtis B. replied 1 year ago.

No difference I assume! did you try it with the muffler off? How is fuel quality?