Haven't started washer in 3 years. What should I do besides new gas. It's a workforce 2500psi, 163cc. Lost manual can see where choke and throttle are.

Replace the seals.

with a printer ...first you have to find the manual. try google

PartsTree.com

If you have compression then the first thing you check is for spark. If you have spark then you move on to the fuel system. You will have to pull off hoses at a couple of points to see if gas is at the carb and further along. If it is the carb then a simple carb kit will work.

leaving fuel in a bowl will cause corrosion in the jets and jam the needle and seat operation
take the carby off the machine and go to a shop that can overhaul the unit

Does your pressure washer engine have a place to add and check the oil level? If it does. And it looks like the picture from your question. It is a four stroke engine and the fuel doesnt need added oil.

Northstar washers are available online at Central Power Equipment.
You might find an electronic owners manual there.

You need to disassemble the carb. and spray with carb. cleaner. If you need tips on how to do this, just let me know. You may need a new carb. kit as well, but we won't know that until you first perform the first step, or if the carb. parts are more than 3 years old. If they are, then go ahead and buy the carb. kit and replace the parts.

Jim

Trace the throttle cable, it probably has a loose mount/clamp somewhere along its length.

Is there an oil sensor unit if it is going bad it tells the engine the oil low and engine wont start. I had same problem with my pressure washer, i just unplugged the sensor unit and it started fine ever since

1. 1st change the spark plug to NGK BPMR 7A.
2. Set the kill switch to on position (I)
3. lock the throttle interlock on
4. Do not prime the fuel bulb...this may cause flooding.
5. set the choke to full choke.
6. pull the cord gently until the piston resists then pull hard
7. repeat pull a second time
8. open choke all the way
9. pull cord again hard.
engine should start within 2-3 pulls, release throttle and feather the throttle until stable