marco Posted June 28 Share Posted June 28 Hi I need help, I've just started a top end rebuild on my GS as it was running a bit rough and had a couple of minor oil leaks. What I found was a horror story, number 3 barrel has two massive grooves in it, the piston was missing one circlip and the other circlip was 2mm diameter too small and ready to fall out. the gudgeon pin/ wrist pin was scraping against the side of the barrel. I've measured my barrels and they are 73mm inside diameter, the pistons are marked with the numbers 350. am I right in thinking that this has been over bored a lot in the past. Am I going to have to get new barrels, pistons and rings? Or can a standard barrel be bored out by 3mm Quote Link to comment
gs7_11 Posted June 28 Share Posted June 28 73mm is a 1085cc kit, probably Wiseco. I've had the same issue in the past with Wiseco circlips. You can get a 73.5mm overbore, assuming the damage in your bore isn't too much. I'd get the 1100cc kit from Cruzin Image. Quote Link to comment
Gixer1460 Posted June 28 Share Posted June 28 Well, according to APE website 73mm is the largest overbore (+3mm) for the GS1000. But subject to the liner thickness you could use 74mm pistons for a GS1100. As it stands that liner is toast so its either replace the liner and overbore it out to match 73mm and check all the others for wear or pull the plug and take it out to 74mm? APE don't list a 73.5mm set but I didn't check everywhere LOL! Quote Link to comment
imago Posted June 28 Share Posted June 28 1 minute ago, gs7_11 said: Cruzin Image 73.5mm kit That's got to be a mistake (or bollocks)? Full kit of four pistons, ring sets, pins and a head gasket for $140:00 (£110:00). Quote Link to comment
marco Posted June 28 Author Share Posted June 28 I just measured the liner thickness and Its 1.4mm thick. definitely toast. it is a standard 997cc barrel that has been bored to its max then Quote Link to comment
gs7_11 Posted June 28 Share Posted June 28 3 minutes ago, imago said: That's got to be a mistake (or bollocks)? Full kit of four pistons, ring sets, pins and a head gasket for $140:00 (£110:00). Nope, just a bargain. I've used 2 of their kits with no problems. As have many others. They're good quality. 1 Quote Link to comment
marco Posted June 28 Author Share Posted June 28 the pistons are fine, can't see a makers mark on them. it's barrels that are my problem Quote Link to comment
gs7_11 Posted June 28 Share Posted June 28 12 minutes ago, marco said: I just measured the liner thickness and Its 1.4mm thick. definitely toast. it is a standard 997cc barrel that has been bored to its max then Not toast. I checked, and Wiseco still make the 1100cc 73.5mm kit too, as sold by SPS. Another 73.5mm Kit Much more expensive. Personally, having experience of both, Id rather use the CI kit. Quote Link to comment
Dezza Posted June 28 Share Posted June 28 If the pistons are fine, then wouldn't the problem be solved by a secondhand reasonably standard block re-bored to size? I have no idea as to how difficult GS1000 blocks are to obtain though. Quote Link to comment
imago Posted June 28 Share Posted June 28 20 minutes ago, gs7_11 said: Nope, just a bargain. I've used 2 of their kits with no problems. As have many others. They're good quality. That goes way beyond being a bargain, it'd cost half that for just the head gasket from the usual sources. Quote Link to comment
imago Posted June 28 Share Posted June 28 5 minutes ago, Dezza said: If the pistons are fine, then wouldn't the problem be solved by a secondhand reasonably standard block re-bored to size? I have no idea as to how difficult GS1000 blocks are to obtain though. There are a few sets on a well known auction site for a bit over £100 with pistons. Quote Link to comment
marco Posted June 28 Author Share Posted June 28 Thanks for the replies, I'm going to try to find another set of barrels, unfortunately I'm in South Africa so no auction sites here and the shipping would be probably more than the cost of the parts. The groove in the barrel is at least 1mm deep so only about 0.4mm left at that point on the liner. at least there's a half decent engineering place near to do a rebore Quote Link to comment
gs7_11 Posted June 28 Share Posted June 28 19 minutes ago, imago said: That goes way beyond being a bargain, it'd cost half that for just the head gasket from the usual sources. I know. In fact, I think I'll order one now before someone catches on! obviously there's shipping to pay, but theyre still cheap, and the 2 I got slipped through customs without any charges. Result! 1 Quote Link to comment
imago Posted June 28 Share Posted June 28 4 minutes ago, gs7_11 said: I know. In fact, I think I'll order one now before someone catches on! obviously there's shipping to pay, but theyre still cheap, and the 2 I got slipped through customs without any charges. Result! I honestly don't know how they do it at that price. Quote Link to comment
wraith Posted June 28 Share Posted June 28 Had the same kit in my gs1000g but it was £84 when I got it probably about 8-10 years ago and never had a problem with it. They are not a high comp kit, just standard comp but they do the job very nicely. As to @marco problem, yes another set of barrels and have them bord to the pistons. I'd replace all the piston clips to be on the safe side 2 Quote Link to comment
Gixer1460 Posted June 28 Share Posted June 28 4 hours ago, imago said: I honestly don't know how they do it at that price. Squished Coke cans is my guess from somewhere in China / India / Asia! 1 Quote Link to comment
gs7_11 Posted June 28 Share Posted June 28 I think it's a fair bet they were made in Asia. As were our bikes. No doubting the quality though. The ones I have here are indistinguishable from OEM Suzuki under close scrutiny. 2 Quote Link to comment
Reinhoud Posted July 9 Share Posted July 9 On 6/28/2024 at 8:09 PM, gs7_11 said: 73mm is a 1085cc kit, probably Wiseco. I've had the same issue in the past with Wiseco circlips. You can get a 73.5mm overbore, assuming the damage in your bore isn't too much. I'd get the 1100cc kit from Cruzin Image. I had the same issue, also with Wiseco.. Didn't know it's a thing.. Quote Link to comment
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