Wiseco pistons

[jetranger]

I just rebuilt the top end on my SL650 and I
used wiseco, I asked the shop that bored my
cylinders for their opinion and they said they
are good for up to 100HP (per cylinder), they said the factory cast pistons are best. the main
reason I used the wiseco was cost, I bought them on Ebay for much less than WSM, they would have been my next choice, the pistons
come with clearance specs and that's what I
had my cylinders machined to (4 thou).
I ran a full tank with extra premix for break
in at no more than half throttle and I always
warm it up at low speed for 5 mins before I
hammer the throttle, and I've had no problems.

[Bryan Glynn]

at 0.004" clearance with forged pistons, make SUER you give it at LEAST 5 min of grdual warm upo. The first time you hammer it in cool water if you are really at that clearance, you WILL lock up.

[cameron da river rat]

i've never seen a wiseco work at .004! i tried "manufactures specs" on my sea doo and after 10 hours of break in, the first time i hammered the throttle it lasted about 4 seconds and "ka-klak", i came to a hault!

my new engine was no more! the front piston siezed up along the skirt of the exhaust port and yes the ports were chamfered. i have had good luck with them in my sea doo 650 set @.0065. two years, so far so good.

i went back with cast pistons in my 720 that previously had the .004 wisecos. but i beg to differ about the wsm pistons since that is what i bought and so far they have three years under thier belt and i check cranking compression after every ride to find no sighns of stopping! i herd they were junk but i'm speaking from experience with them. i can't say i've ever had a problem with them and would recommend them to anyone as well as wiseco pistons. just don't put wisecos @.004, and let em warm up.

but i do recommend cast pistons for rec riding, just for the fact of the special steps to be taken with forged pistons. but then again, i think the wisecos will hold up agianst detonation ten times better than cast and on all the sea doo's i've taken apart the rear piston has always detonated itself to death! what the cause is, i can't say. crankshaft toirtioning, air leak, too lean of high speed jet/adjuster, closest to the jet pump to recieve most of the load.........................don't really know.

just my 2 cents [img]tongue.gif[/img]