Piston ring compressors? Bandit cyl install driving me nuts

I've done probably a dozen motors and never had problems like this before. Granted, the majority were twins and singles, but I have done I4's before. I bought some high comp 1246cc JE pistons for my Bandit. Cyl came back from the machine shop today, so I put the rings on the pistons and put the pistons on the rods. I cannot for the life of me get even one piston to even get past the top ring into the cyl. I have a Moose brand piston ring compressor, but it kinda sucks and is proving to be very little help.

I'm out of ideas. I've never had a motor put up such a fight to go back together.

 

JE pistons sometimes have really flimsy oil control rings, but you're starting with the top ring. The piston often goes in a lot better from the top. The cylinder usually has a slight chamfer there. You can do it the way you're doing it, but from the top is easier, and if you're having trouble, that might help. You can do them one at a time, then set your cylinder in place, flip the motor, bolt the caps, assemble the cases, and done. Use oil, Marvel Mystery Oil is good because it won't try to glaze the cylinders on break in. Best idea is a Wiseco install tool. Modern bikes are nearly impossible without one. Or at least I'm super spoiled by them.

Piston diameter? Maybe I have one you could borrow, although they're not expensive.

 

81mm pistons. I had thought about doing them from the top, which is how I do my Harley motors, but I thought then fitting the pins and circplips would be an ever bigger PIA.

I had previously used MMO, but this time I'm trying Permatex Ultra Slick Break in oil,

 

Biggest install tool I have is 78mm. If you continue to struggle, get one, they are about $30. Fit your pistons to the rods, fit the cylinder to the block, use two lengths of the appropriate diameter hose to slide on the studs or bolts (two pieces katty-corner) to hold the cylinder in place, then pop them in from the top and flip it, stick the crank in, and bolt the end caps on, remove the hose hold-downs and continue with assembly. This is how I do the R1 or any bike with non-modular cylinders. Some builders hate using oil, but I use plenty and then do some clean up.

Once you use the install tool, you'll wonder how you ever did it before.

 

Well, I got it done but had to borrow a tool from a dealership (car) mechanic friend of mine. Total PIA. To make it even more fun, I installed the intake cam sprocket 180 degrees out (swapped in a GSXR cam so had to transfer the sprocket) so I had to undo a little work and fix that. Found it when I went to set valve clearances. Luckily I had only rotated the engine twice by hand before I caught it. Hopefully I didn't mess up a valve.

 

je are a nitemare, so much so i opened the grooves and fitted OE rings of the same diameter. went together like a breeze.

 

Shouldn't have to worry about value to piston contact as both cams would still be in time with the crank. Just out of time with each other.

 

That's what I told myself, but I'm paranoid, and obviously not a pro engine builder.

 

edit - I can't get the video to embed but long story short it fired right up, purrs like a kitten, idles great and doesn't smoke or make any stupid noises. I hope to ride it a little today.

Thanks for the help.