is it ok to bore 99 gsx cylinders

[bighvygsx]

bought a 99 gsx rfi and the guy told me it needed a tune up. (my fist pwc) well needless to say it was running in one cylinder the rear one had been blown for a long time. i found a place that will bore and hone and match new pistons and rings and gasket kit for 300.00. my qusetion is it says if you bore over .010 you need to relieve the RAVE valve. they say with a sander or grinder. is it ok to do this? doesnt sound very percise.

 

[nswillin]

What says you must do this? The manual on your seadoo says that your first bore over is .010 or .25mm. If you go more than .25mm then you will have to rework the rave valves or they will hit your pistons. If your just going .25mm over than your good, you will have the min. clearance of .375mm required.

If you do go more than .25mm, say .5mm then you would take .25mm off of both rave valves. This can be done precisely but you will need a dial caliper to etch a line on your valves so you know how much to take off.

 

[seadoosnipe]

Or......?

Or, you could order a new top end kit for $475 and replace both cylinders, pistons and all new gaskets for half the work. Your going to bore for $300, so for $475, it's like your getting that other cylinder and piston for $175....hmmmm, that sounds like a good deal to me!:cheers:

 

[nswillin]

Thats a good idea from seadoosnipe also. I was gonna do the same thing but I called the place I was buying from and they said they new cylinders they send you are oversized as well.

 

[seadoosnipe]

hmmmmm?

From what I understand, they aren't, because they are removed and re-sleeved. If they are re-sleeved, that would be standard bore.

When you bore, they bore the sleeves currently in your cylinders. When you send them in as cores, they remove the old sleeves, make any repairs, then re-sleeve to standard bore and send out standard pistons with it.

That's not the first time I've got two different statements from them though. Asked about shipping weight before, answers were different, twice!

 

[bighvygsx]

this is were i was going to get it done for 300.00. they say anything over first bore .010 to rework rave. where can you get the whole top end for 475?
http://fullboreonline.com/cylinders_topends.htm

 

[nswillin]

I tried www.sbtontheweb.com. I bought the top end kit from them at .5mm over and reworked my raves.

They do do a cylinder exchange for 475. I was gonna do that but when I called they said that the cylinders they send you are over sized.

Seadoosnipe knows way more about this stuff than I do, he says they should send you standard everything. So, you need to call before you order and find out what they are gonna send you. It was gonna be two weeks waiting on the cylinder exchange for me, so I just went with the topend kit and got it in 3 days. Hope this helps.

Also make sure your kit comes with new needle bearings and go ahead and order new exhaust gaskets as well. Also be very very very careful when taking the old pistons off cause the cageless needle bearings that are in there will try to go everywhere, don't drop anything into the bottom end of the engine. I stuffed rags into the holes just in case and caught all the bearings with a magnet bowl. Your new bearings will be fully caged so nothing will have a chance to spill when installing.