Trying to get my brothers Banshee up and running again since it runs like crap now.

The whole story is that He bought it needing rebuilt and then rebuilt with new crank, pistons, rings, and domes put in and then broke it in and it ran absolutely perfect, but it had pod air filters installed and we ride in dusty areas and also have water and creek crossings.
So he decided to put on a stock airbox, so we bought one with a prodesign intake and a k&n filter and installed it.
Of course, as expected, it ran like crap and would not hit the power band and it would just gurgle at anything above half throttle.
I helped him to put in jets, expecting it to have bigger jets to run pods, but when opened up I found 200 mains (stock) and 25 pilots.
Went ahead and put in the 220's I was thinking would work with the k&n filter, but no dice. It runs worse than ever now.
I have no idea what is going on, but now it won't rev up at full throttle even if I put the pods back on! It ran perfect before putting on the airbox.
I should mention that the quad is all stock besides the K&N filter, cool head, and it was bored .020 over when rebuilt. Has stock pipes. Also has new clutch, new crank, new pistons, new flywheel, new timing plate; only about 15 hours on all new parts.
Any idea what is wrong with this Banshee?

 

No one able to help? I wanted to post over at Banshee HQ, but couldn't create an account over there.

 

Does it still have the TORS on it? try unplugging them. Recheck your crank keyway make sure it hasn't slipped.

 

I have tried with TORS disconnected and connected with the same results. Currently have the flywheel and stator off to try a different stator I was able to borrow, and the keyway and key look perfect.

 

What about the petcock. Is it get a good flow of fuel? try RES.

 

petcock works fine and all new gas in the tank and carbs. It is way to rich with stock jets. Have 200 mains in it and it gurgles and bogs at 3/4 and up throttle and the plugs both come out black.

 

the stock air filter is for stock jetting, with the air filter change you might need to go up a size on the pilot what elevation are you at?-that determines the main you need.

check your transmission oil level, if it is lower than it should be your seal on the clutch side might not be seated right as the crank was changed. that would cause the clutch side plug to foul or go black as the oil would go into the cylinder and make it rich.

the plugs should be a br8es that is stock and should not be changed unless you are running in hot weather

did the cylinders get honed when rebuilt?

 

Are you back to 200 mains? Couldn't tell from your post above...99.9% of the time the main from the factory is jetted RICH...this is for warranty purposes...so if all stock you may actually want to go down a size vs. up. If your plugs are black after running WOT then your main is RICH...

 

Running terribly with the 200 mains and 25 pilots. It ran perfect with the pods before the airbox was installed, but now switching back doesn't fix it.

It ran perfect for 15 hours with the pods. No problems with the crank seals or the oil level. Just bought fresh oil to do a change tomorrow when I have time to look at it.

Using new NGK BR8ES plugs, switching between 2 new sets and cleaning them when they are removed, but both sets have less than 10 minutes on them.

Both cylinders are running rich. Also have no powerband.

The cylinders were bored and honed for the rebuild.

I am at about 750 feet above sea level.

I can't find banshee type hex jets leaner than stock

 

I still think it has something to do with the TORS. When I did the top end on my grandson's Banshee I did a TORS removal. Quad ran crappy until I unplugged the connection under the fuel tank, not the TORS themselves.