piston size? more 701 specs

[JStahre]

my pistons have 1.50 stamped on them .. what does this mean and how many sizes can a 701 be bored too? also i was givin some bad info on
jetski News group and i tightend my engine casings
29 ft. and 38 ft on brackets how bad is that i have run it for an hour but am contemplating taking the motor back out , should i ???

[Bryan Glynn]

That means they are 1.5mm oversize. That is just about, if not, the, limit for that engine before it needs to be resleeved again.

Case bolts shouldn't have any problem with near 40 ft. lbs. - don't worry about that. I'll check the actual specs in the morning, but it'll be close.

[CaptToyota]

I will check my factory Yamaha book when I get home, but if I recall, based on my 1100 crankcase bolts, the 8mm threaded will be 21 and the 10mm thread wil be 29. the jug to the case is also 29 if memory is functioning,, but let me look.

[Bryan Glynn]

The small bolts are 11 then 20, the large (bracket bolts) are 17 then 38.

[CaptToyota]

Bryan is correct, I'm home and I pulled the 701 page in my factory Yamaha book for the crankcase
and those are the numbers given in 2 steps.
Let me clarify Bryans small/large bolts--small will be 8mmx1.25 and use the 12mm socket, large will be 10mmx1.25 and use the 14mm socket. Just don't want to see you try to pull 38 on a 8mm bolt, you'll rip the threads right out--OUCH!
For the pistons, Wiseco offers pistons up to 84mm
bore (+3mm), Riva has same in their catalog, and make no mention of sleeve replacement, as Bryan says, beware of excessively thin liner. Did you measure the piston diameter yet to actully determine current bore status? Standard is 81mm (3.189-3.190), each .020 beyond will represent another .5mm.

[ August 06, 2001: Message edited by: CaptToyota ]</p>