BannedCR500Riders.com

What is the maximum you can go on the 500 cylinder? can you reliably get 91mm out of it? or would you call 90.5 the last straw and start looking for a new jug? or sleeve?

i have examined all my cylinders and sleeves 1000 times and would have no worries putting 91mm slug in there. honestly i would feel safe going slighly bigger if pistons were available. this is only my personal thoughts for my own machine and by no meens am i a machinist

I had a chat with TT earlier and he gave me some good advice so.. ill probably stick with his advice for the most part... 90.5 will be my last bore before i track down a good jug. Hey Glenn as soon as i can save up a bit more money im going to get it taken care of with one of TT's pistons

hahahaha I see how it is Nick

This was my 86 @ 91mm when I tore it down last year,I had a pic from the top with the head off but I can't find it,honestly I think theres another .5mm left in it but it would be very thin

I've mentioned it before, but here is my '86 jug with the broken sleeve. It had been resleeved at one point, and it probably contributed to this, however the bore was 90.5.

didnt 89' and up have a thicker sleeve then 88' and earlier, so you should be a little safer with a bigger bore

blownbillybob wrote:didnt 89' and up have a thicker sleeve then 88' and earlier, so you should be a little safer with a bigger bore

yup, but not sure if that changed in '89 or '90 since the '89 kept the old piston and porting.

ok mike ill just send it to you.. LOL I need to spread the vendor love ya know.. Ordering parts from you machinework from another vendor We will talk next week .

Fastkart thats exactly what im afraid of going much more over 90 and im hoping at 90.5 i can get away with it for a season while i look for a good used jug or just buy a new one so i can go back to oem pistons

However vertex or prox one of the 2 offers a 90.25 but i dont know if i want to go back that way just because of the one i have on my desk is smiling at me.. Its a prox at 90 and im glad i cought it when i did cuz that would have made a horrible racket shooting the hill at dumont..

Honda say's 89.40mm is it for a stock bike.We do bore to whatever a mans pocket book can stand .We have done several engines for the fast guy's and some of top HillClimbers to 91.00mm. A lot of the fast guy's who want a 540 engine we have to bore to 91.00mm with a stroker kit. The main thing in boring to tho's larger bore sizes is to make sure you get a straight bore ,A lot of times failure comes from a crooked bore because the machinist doesen't get the cylinder lined up in boring bar properly,But That's why there is so many different prices on piston kits tho is what a man's pocket book can come up with.We charge the MFGS.Suggersted price and take10% to25% off on the parts if we do the machine work thats how we can have a low price on the machining,and Race Porting, most of the time we include Piston,Seals,Gaskets in the job. .But we don't make a big thing out of it if a man want's to furnish his own parts, We welcome if a man sends us his own pieces that's why we work hand in hand with the customer and have been in business for 42 years the last 15 years specializing in the CR-500 engine.Glen (TEAM GSS) NAHA #42

YA GOT TO LOVE GSS SHOWING THE LOVE

lewisclan wrote:YA GOT TO LOVE GSS SHOWING THE LOVE

X2

Thanks Santa......

dannygraves wrote:

blownbillybob wrote:didnt 89' and up have a thicker sleeve then 88' and earlier, so you should be a little safer with a bigger bore

yup, but not sure if that changed in '89 or '90 since the '89 kept the old piston and porting.

checked my old 89' cyl. today it has the thicker sleeve in it and its bored 91.00mm over with .007 clearence and it ran dam good to till i ran out of gas right at the top of a hill climb at carnegie, leaned out and stuck the rings on the exh. side at the bridge, who ever the GILLIGAN was that bored it didnt releave the bridge at all it was all that extra clearence that let it live that long cause i ran it for 8 mounths and i bought it like that and the guy had big hours on it allready. yes 89' kept the old piston but i think has the newer porting

Heres a better shot of my 86 2mm over

that looks THIN... waaay to thin for my liking especially when i hammer on it for a hour straight in the dunes..

ISBB wrote:that looks THIN... waaay to thin for my liking especially when i hammer on it for a hour straight in the dunes..

It is thin,but it still rips,I put some good hours on it since I had it and who knows how many were put on it before me?,I did a little history check on this bike when I got it and All Season Cycle in Brooks,Alberta installed this 2 over piston in 04.I've got a sleeve and piston ready to go in before it gets put back together