[XplicitRacing6]

You heard it right folks. I believe I have a jetting issue. My quad boggs out really bad and backfires ALOT. Its a 1999 400ex. The motor is stock. I'm not sure if it is the right jet in the carb. But what size jet do you think I should start out with?

 

[SamUK]

Man.... Your not kidding when you say a flame are you!!

I’m no help with sports quads unfortunately, all I can tell you is to take the plug out and see what that tells you. There’s A LOT to knowing when your fuelling is spot on, I’m still learning. A few on here are awesome at fuel/air diagnosis.

 

[mac102004]

Running rich judging by the huge orange flame.

Stock carb settings are

Main - 148
Pilot - 38
Needle - 3rd groove from top
Pilot Screw 2 1/4 turns out

So I'd start there.

 

[SlammedRanger]

Is this the quad you were talking about that has a cracked header? If so there is your culprit!

 

[Duck0fDeath]

Wish my quad shot flames like that....I'd leave it :grin

 

[XplicitRacing6]

Wish my quad shot flames like that....I'd leave it :grin

I wish I didn't keep it. I think I did something to the head. Its starting to leak oil out of the head really bad. I'm extremely ****** because I spent 6 hours putting this thing back together. It was running extremely rich. Oh well I deserve it for riding it when I knew something was wrong.

 

[XplicitRacing6]

Is this the quad you were talking about that has a cracked header? If so there is your culprit!

Nope I changed out the headers. This one is all good

 

[Duck0fDeath]

Ouch! Sorry, man.

 

[XplicitRacing6]

Ouch! Sorry, man.

You win some you lose some. I have another 400ex motor so if I need to ill use that one

 

[SlammedRanger]

I wonder if it had a partially blown headgasket? Could have been why it was popping flames. My buddies quad i rebuilt was doing that. Turned out someone used a crappy winderosa fiber headgasket and it would leak worse and worse the hotter it got. And would pop and bang and flame out real bad when you would rev it. I pulled it apart and put a good mls cometic gasket on it and we did gt thunder studs at the sametime and it has ran perfect ever since. Zero popping and no more flame out.

 

[XplicitRacing6]

I wonder if it had a partially blown headgasket? Could have been why it was popping flames. My buddies quad i rebuilt was doing that. Turned out someone used a crappy winderosa fiber headgasket and it would leak worse and worse the hotter it got. And would pop and bang and flame out real bad when you would rev it. I pulled it apart and put a good mls cometic gasket on it and we did gt thunder studs at the sametime and it has ran perfect ever since. Zero popping and no more flame out.

Oh wow that sounds like the exact same thing mine does. The hotter it got the more oil that came out. Thanks for telling me that. I'll probably tear into it tomorrow night

 

[TBRider]

You just need to duct tape a hotdog grill rack above that and you can have a hot meal after a 5 min spin.....lol

 

[XplicitRacing6]

Heres a pic of the head

 

[XplicitRacing6]

You just need to duct tape a hotdog grill rack above that and you can have a hot meal after a 5 min spin.....lol

Haha. Ill post a slow mo video of it if you guys want to see it

 

[XplicitRacing6]

 

[fishfiles]

People would pay big bucks if they could get their quads to shoot fire out it's butt -------- and you want it to stop LOL

maybe a timing issue like a slacked chain or poorly seated valve , sticking valve a bent rod will also act like a timing issue ( been in the water lately ?)

 

[XplicitRacing6]

People would pay big bucks if they could get their quads to shoot fire out it's butt -------- and you want it to stop LOL

maybe a timing issue like a slacked chain or poorly seated valve , sticking valve a bent rod will also act like a timing issue ( been in the water lately ?)

Maybe I should have an oil Kerosene a inlet and a spark plug in my exhaust to make it do it haha. I'm going to be pulling the motor out and doing some surgery on her. I haven't taken it near any water.

 

[fishfiles]

Another thing I think will make it pop is a crack or bad seal around the carb boot ------pull the engine out ??? you got 300ex right , can you take the head off in the frame on one of them ?????

 

[fishfiles]

That would be cool to have a spark plug at the rear of the muffler and a switch to turn it on and spray some kerosine you say , at might with a buddy right behind you , man that sounds like some fun

 

[SlammedRanger]

That is a blown head gasket no doubt about it!