Jet size help. Detonating. glowing head pipe and back fire.

[fknboss]

Im not the best with carbs. But i can rebuild them so I should say im ok but no good at tuning them. I bought this quad ran good had a top end noise. Ended up the race thats pressed on the cam for the inner bearing was gone and timing chain (tensioner side) guide was backwards. Got this all straitened put it all back together the the timing chain was way stretched. To it back apart new chain installed and back together. Not starts right up but is detonating and the head pipe is glowing red and back fires so im assuming lean and very. Timing is dead on.
Mods wiseco piston kn filter with holes in the lid and dg full krome exhaust.
Rechecked the valve lash its perfect all the fuel is new 93 octane plug looks fine burning wise its new but i wont let it run long enough. I had the carb set at 1 1/4 from lightly seated air fuel mix screw.

The noise sounds like a tinny like a socket tapping the head pipe. Its not constant its pretty spuratic and doesnt seem to do it with the choke on. It starts when you put it at half choke.

 

[Gen1Pat]

You need to turn that mixture screw out to 2.5 turns and see what it does before you get involved with jets and fetting.

 

[fknboss]

I did that as well my buddy says it got a little better but i didnt notice a change

 

[fknboss]

Im gonna pull the needle to check what slot its in. Ive read stock should be in the middle.

 

[fknboss]

Well the needle was at middle setting (3) i moved it to 4 to move the needle up no change. I just took a video going to post it see if anyone has any ideas.

 

[fknboss]

Here is a video. Sorry for shitty quality it was from my buddies iphone then text messaged to me. But you can hear it loud and clear and see how fast the head pipe turns red. I just started it soon as vid started

https://www.youtube.com/watch?v=k9yLn4_0BNo&feature=youtube_gdata_player

 

[slash]

man your timing is way off , late or retarded timing will pop and overheat exh, did this on purpose 1 time on a small block chev and dropped a exh manifold on the floor melted ..

 

[fknboss]

Timing is spot on

 

[Gen1Pat]

The video wouldn't load for me. What size pilot jet is in there? If it is stock it is too small with the exhaust and modded a/b lid you have.

 

[fknboss]

The video wouldn't load for me. What size pilot jet is in there? If it is stock it is too small with the exhaust and modded a/b lid you have.

I thinking the same thing. I think pilot jet is stock at 42.5 im going pick up a 45 and 150 main im waiting on gasket kit to pull it apart and find jet sizes that are in it.

 

[fknboss]

Try going to youtube and typing warrior detonation its the first one that pops up

 

[Gen1Pat]

You are going to want to see what size is in there already, and that way you know what to get. Also, get way more then just the next size.

 

[alex456123]

Could it be a cracked intake boot too

 

[Gen1Pat]

Yes it could be.

 

[fknboss]

The intake boot was dry rotted but covered it completely in silicone. I dont think its leaking even tho ots a temp fix

 

[alex456123]

Guarantee it's the intake boot weather or not you covered it in silicone if its dry rotted it will leak.

 

[fknboss]

 

[fknboss]

This is what i did

 

[Gen1Pat]

Spray the intake while running with carb cleaner and see if engine races or dies.

 

[YAMAHAULER]

get a new intake boot silicone won't do **** if its dry rotted