400ex no compression!

[zbojnik19]

Sounds like the decompression spring on the cam is stuck happened to me after fresh rebuild I tore the whole quad apart trying to find out what was wrong

I have a stage 1 hot cam installed, there is no decompression lobe.

[zbojnik19]

is it possible that the carb could not be delivering the fuel?

or spark timing is off?

[Zakradu398]

What is your jetting

[zbojnik19]

180 main and 45 pilot

[DragonGunner]

is it possible that the carb could not be delivering the fuel?

or spark timing is off?

Put a dry plug in....open throttle a bunch of times to try and flood the motor, try hitting the starter to crank it a few times while hitting the throttle. Take plug out, should be wet with gas....if its dry then fuel isn't getting to the cylinder to fire it.

[zbojnik19]

Put a dry plug in....open throttle a bunch of times to try and flood the motor, try hitting the starter to crank it a few times while hitting the throttle. Take plug out, should be wet with gas....if its dry then fuel isn't getting to the cylinder to fire it.

Took the plug out while cracking and doesn't seem to be getting fuel. I'll clean it the carb again but what else can block fuel from getting in?

[DragonGunner]

Took the plug out while cracking and doesn't seem to be getting fuel. I'll clean it the carb again but what else can block fuel from getting in?

Wrong timing, intake valves stuck closed.

Check if fuel is reaching carb from the tank. Clogged fuel line. Clogged strainer in tank. clogged fuel tank breather tube.

Carb float needle valve clogged or stuck closed.

[zbojnik19]

Cleaned the carb again and still nothing I put my hand over the carb when cranking as send like alot of fuel is sitting back out

I dint know what else to try

[DragonGunner]

Cleaned the carb again and still nothing I put my hand over the carb when cranking as send like alot of fuel is sitting back out

I dint know what else to try

so your getting fuel to carb, when you pump it fuel is coming out of carb.....so did you try and check your plug to see if its wet..? If its not getting fuel to the cylinder it will never start. I would double check how you timed it, doesn't sound like the intake valves are opening to allow gas in. We really can't go any farther until you find out the cause gas isn't getting to cylinder, check your T mark again making sure its TDC, check your valves.....or just take it to a bike shop. They will be able to see what I can't and can figure it out in probably 10 minutes and you'll be riding again.

[zbojnik19]

So I bought a new number 9 spark plug and now I'm getting back fires every 10th ish crank. Backfires from intake and exhaust.
Making progress but still no idea. ..