Changed needles, drilled slides - won't start!

[mattvfr400]

Wacked my carbs off, put some new needles in, drilled the slides set the pilot screw to 2.25 (aftermarket can) and went to balance the carbs after doing so and the bike simply will not pick up and start. There's fuel, spark etc but just won't fire up. The pilot screws were originally 3 turns out so I set them to 2.25, no luck and now back to 3 (worked fine for months) and she won't fire up! Any help?

[bikemonkey]

Carbs seated correctly? Waited long enough after cranking for fuel to fill the carbs? (remember the tank tap needs a vacuum to operate and let fuel flow)

[mattvfr400]

Carbs seated correctly? Waited long enough after cranking for fuel to fill the carbs? (remember the tank tap needs a vacuum to operate and let fuel flow)

Good seat yep. Oh god yes gone through nearly 60 seconds of solid cranking still nothing. Done this multiple times. Fueling is not an issue, I just suck on the vacuum and stick a screwdriver down the line, when dissasembling there was plenty of fuel in the pipes and carbs.

It was very cold outside so I've bought the bike in, give the carbs another whizz and see if it'll turn over with abit of indoor warmth! Will having the balancing kit on affect the starting in anyway?

[bikemonkey]

Shouldn't do.

You must have disturbed something, take the carbs back off and check them over, then re-assemble checking as you go.

I can't see why it won't start if it's all together correctly

When was the last time the carbs were cleaned?

[mattvfr400]

Shouldn't do.

You must have disturbed something, take the carbs back off and check them over, then re-assemble checking as you go.

I can't see why it won't start if it's all together correctly

When was the last time the carbs were cleaned?

That's the issue, haha! Yeah I agree somethings wrong somewhere. I've set the pilot screw to exactly 2.25 turns out from fully in. Checked all the bowls and floats etc. They're clean on the inside! The carbs were cleaned only a week before today. I cleaned them the other week, no issues everything great. Fit the needles and drill the slides, attach the balancing kit and no luck with it firing up. Hoping the warmth of the room will be enough to give it a helping hand. I'm quite meticulous when it comes to the carbs so for it to not fire up after putting the carbs back on I was shocked as to what it could be!

[bikemonkey]

Yeah this is completely stumping me too, maybe you flooded the engine?

[mattvfr400]

Yeah this is completely stumping me too, maybe you flooded the engine?

Right update for you! Whizzed the carbs clean, wacked em on the bike with the air filter etc and tank. Sucked on the pipe for about 10 seconds, plugged the vacuum. BUT THIS TIME I STARTED IT, I'm getting incredibly loud bangs every 10 seconds of cranking....very loud bangs, hurt my ears! I can't spell petrol to see if it's flooded...I've double/tripled checked everything! I seated the carbs really well and fastened them tight!

Running out of ideas....I'll leave it a little longer then go back and see if I can get her running. She was only running yesterday!

[bikemonkey]

I take it the bangs are coming from the exhaust?

[mattvfr400]

I take it the bangs are coming from the exhaust?

Very silly of me to not specify! Yes the exhaust, along with very large flames. Which I presume is just the WD40/carb cleaner burning but damn she will just not fire up! I'll leave the bike for the night to warm up in the house and dry out if the plugs are moist or something haha losing the plot here!

[bikemonkey]

Yeah I'd walk away and leave it until tomorrow, maybe a fresh head will help