gs1100 2 valve block boring

[Big E]

I have had one bad turn of events after another with my gs1000s. I had a problem with the motor at first well it turns out it is a crank issue (twisted crank). I have a new crank on the way and I have put the better flowing gs1100 2 valve head with 34mm mikunis on it and the 1074 block (jugs) with 1074 pistons.
My question is can I bore the 1074 block to a 1085 and use the gs1000 1085 pistons in the 1100 block since the sleeves are alot thicker.

[doctorgonzo]

Pretty sure yes, that GS1100 block will bore to 1085 no problem. I am running a similar setup on a 1000G. I put the 1100G head on it, and bored the 1000 block to take the 1074 pistons. Not sure why you'd want to go to the trouble for 11 more CC unless the 1085s are high compression pistons (which I guess they are).

[Big E]

No they are not high compression I didn't really know if it was worth the trouble or not ,but the pistons I have (1074) are used, would you suggeast putting new rings in and if so what work would need to be done to the block.

[doctorgonzo]

No they are not high compression I didn't really know if it was worth the trouble or not ,but the pistons I have (1074) are used, would you suggeast putting new rings in and if so what work would need to be done to the block.

Just me, and I've only built one engine, so much more experienced guys here, but I'd put new rings in. The rings on the 1074 pistons might still be good, but why take that chance when a set of rings is $90. Used pistons are fine unless they are scarred up. Just replace the rings and the circlips that hold the pins. I put used 1074 pistons in mine. Bought them from a guy on theoldskoolsuzuki board for $50 for the set. So, new rings, new circlips, and hone the cylinders should do it. FYI (and I only found this out recently), but apparently this will actually make your engine a 1054, not a 1074 because the 1000 crank has a slightly shorter stroke.

[Big E]

Ok thats what I will have done cylinders honed and new rings. I thought the shorter stroke would make a difference I just didn't know how much thanks.

[doctorgonzo]

Ok thats what I will have done cylinders honed and new rings. I thought the shorter stroke would make a difference I just didn't know how much thanks.

It added some bottom end ass to mine big time. It seems to have moved the power curve down a bit. It used to not pull for crap til about 4000, now it will pull well from 3000. I still haven't had a chance to run it hard all the way through the gearbox to see how the top end is. I was banging off the 85 on my speedo as I was hitting fith gear on a pretty hard (shifting about 8000) run a few weeks ago when the weather was still good and backed off it.

Also, after the rebuild (and this is the general consensus by folks on this site) throw everything you ever heard about "breaking in" a motor out the window. Fire it up, only let it idle the absolute minimum needed to warm up, check what you need to check, then take it out and ride 10 or 15 miles running it semi-hard, shifting at 6000 or so. Stop, check for oil leaks, parts fallen off etc (ha), fire it back up and ride another 20 miles or so running it pretty hard, shifting at 7500 or so, running it up, backing it off, running it back up, etc... Repeat check for fallen off parts, then take it out and ride 20 to 50 miles like you were being chased by the cops. Come home, and dump the oil and change it and the filter and you're ready to go.