Help! My friend put on 310 kit on his 89 250R nad it keeps blowing the base gasket. Is he doing something wrong? Is this normal? Any tricks to prevent this?

First, make sure the bottom of the cylinder is in excellent condition, no deep scratches, etc. Make sure it's flat.
Next, make sure the condition of the engine cases are the same.
Now, use Honda gaskets, not Cometic or any of those others, get Honda.
Get some of that high temp BLACK silicone and use some of it, not a lot, just a little on both sides of the base gasket.
Make sure the cylinder studs are in soundly.
Now, put it together and torque alternate corners a little at a time.
If that doesn't work I have no idea. .. .
Good luck!

I'd follow what washroad said, and;

The timing could be off. I use Permatex High Tack Gasket Sealant or gasket adhesive to set the base gasket.

[ 12-18-2002, 12:35 PM: Message edited by: tony_250r ]

Make sure that the two cylinder locaters are around the studs are not bent or missing. Cleanliness is very important also.

[ 12-19-2002, 09:27 AM: Message edited by: Oldman ]

I don't use anything on my paper gaskets and I haven't blown one yet. I have aftermarket ones. The only Honda one I have is my clutch cover gasket and the top is leaking a little bit. I guess you have to put gasket sealer on Honda gaskets. Oh, and if you want the best, get three bond 1100. Oh, and make sure he torques the cylinder down then retorque it after a few warm up/break in rides. Then re-torque it after a few hard rides. Then every couple of months there after.

Allways! use Yamabond it is the stuff.
Fuzzy