Did I blow my Banshee top end?

Bansh88

Bansh88

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We were out on Presidents and took a small night ride with the kids.  My on our way back, my daughter said she couldn't kick the bike over.  I ran over, had some issues but kicked it over and revved it up.  Daughter stalled it and it would not kick over again. 

The kick starter would not move.  By hand, you could slowly tap it down, down, down.  Towed back to camp.  Nothing has changed.

This is a 2002 Banshee.  Stock top end.  No mods except pipes, reed cages and 2in1 carb.

What am I looking at here?  Did rings go out?  Something seize?  Just replace pistons or need to hone cylinders as well?  Is this something you're not sure until the engine is apart?

I suppose it's time has come as there are a lot of hours on this bike.  Ideas, places to take?  Not sure if Allen Fox is still around.  

 
Until you open it up you won't know what exactly you did or need to replace.  More then likely your going to need to bore the jugs and put in new pistons, rings and wrist pin bearings.  That would be the best case scenario on a bike this old.  Even if you just caught a ring on a bike that old with a  good amount of hours on it your not getting away with just a hone. If your lucky the cylinder is not that worn and you only have to go up one step on the piston. Again your not going to know until you get it opened up. 

Until you do get it opened up don't be buying parts. You want to open it up and take the pistons and jugs to whomever your going to have do the machine work.  Let them measure the jugs and see what size piston you need to go to.  A good shop will not bore the jugs until they have the pistons in hand to measure. so buy the pistons and rings from them. 

Your looking at a day to take it down and a day to put it back together it is pretty dam easy. Back when I had mine I want to say it was maybe $300 per side for everything.  Don't cheap out and not replace wrist pin bearing because if that goes boom you get to replace the crank and that is $$$$$ compared to the price of he bearing.

Worst case you hurt the bottom end or it is worn out.  you wont know that until you have it opened up though.

 
wopachop said:
Any chance non mixed gas was put in the bike?
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Negative.

I'm in northeast San Diego so an East County shop is what I'll be looking for.

Not looking to cut corners.  Was just curious what this might be.  I'd like tis to run another 20 years.  I got the feeling my daughter not being on the pipe or staying in too low a gear may have been a cause of this.  She's been the primary rider on this for the last year or so.

 
Bansh88 said:
Negative.

I'm in northeast San Diego so an East County shop is what I'll be looking for.

Not looking to cut corners.  Was just curious what this might be.  I'd like tis to run another 20 years.  I got the feeling my daughter not being on the pipe or staying in too low a gear may have been a cause of this.  She's been the primary rider on this for the last year or so.
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Not being on the pipe will fowl plugs not wear out pistons.

 
MWB said:
Until you open it up you won't know what exactly you did or need to replace.  More then likely your going to need to bore the jugs and put in new pistons, rings and wrist pin bearings.  That would be the best case scenario on a bike this old.  Even if you just caught a ring on a bike that old with a  good amount of hours on it your not getting away with just a hone. If your lucky the cylinder is not that worn and you only have to go up one step on the piston. Again your not going to know until you get it opened up. 

Until you do get it opened up don't be buying parts. You want to open it up and take the pistons and jugs to whomever your going to have do the machine work.  Let them measure the jugs and see what size piston you need to go to.  A good shop will not bore the jugs until they have the pistons in hand to measure. so buy the pistons and rings from them. 

Your looking at a day to take it down and a day to put it back together it is pretty dam easy. Back when I had mine I want to say it was maybe $300 per side for everything.  Don't cheap out and not replace wrist pin bearing because if that goes boom you get to replace the crank and that is $$$$$ compared to the price of he bearing.

Worst case you hurt the bottom end or it is worn out.  you wont know that until you have it opened up though.
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Spot on...just need to add you'll have to see if its just a worn part like MWB is suggesting or there was a lean condition somewhere...crack in an intake, side case seal, etc.

Old 2 smoke bikes eventually this happens, fix it right and get another 20 years out of it.

 
Allen fox is still around. 619-445-1415

top end is really easy to do. If you want to save a few $$ take allen your cylinders and head. He can bore/machine as needed and match order pistons for you. 

 
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Fwiw, allen has a full dyno; after its fixed have him tune it. Will run great and wont blow up from being lean

 
Here’s another Guru. His website sucks but he does everything banshee and 2 stroke related. His name is Kevin Herr. Located in San Diego. Give him a call. Real cool dude. 

E2B7B10B-FD02-487B-B8DD-6F1FABEC01CA.png

 
Bansh88 said:
I got the feeling my daughter not being on the pipe or staying in too low a gear may have been a cause of this. 
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This might be your answer. Lean condition due to riding at 1/8 throttle. Little late now but could have adjusted the air screw to be extra rich. Or even pull the choke partially out when the kiddos ride the bike. 

Imagine the bike revving at 5000rpm at 1/4 throttle. Youre not getting much gasoline and lubrication. 

The same bike at 5000rpm and wide open throttle is getting a lot more oil onto the piston.

Being a 2002 i would split the cases and do the main bearings. Ive got all the tools if you wanted to borrow them and do it yourself. Keep it in mind as an option. 

 
No interference fit on the crank? Didnt know that. 

I collected a bunch of fun tools doing my YZ that might cross over to the mighty banshee. 

Dial bore indicator. Ignition timing gauge. Set of blind bearing pullers. Set of drivers that have a lot more contact area than a socket. Moly based lube. Case sealant. Case splitter. Crank puller. Clutch Holder. Flywheel Holder. Metric thread chasing set. 

 
Sausage450r said:
Fwiw, allen has a full dyno; after its fixed have him tune it. Will run great and wont blow up from being lean
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He’s also still in the same location! Here I am reading this at 12am and Allen’s name and number popped into my head. I can’t believe I still remember his number!

 
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