Source for replacement pistons for my GS1000S?

[Anonymous]

Why is is that nobody can make a piston that will last a summer of dirt bike riding? I had one blow apart in my CR250 and it got gobbled up major. Over rev it once and boom.

Steve

[cbxchris]

I don`t know if they still do it but CR`s used to have a bad reputation of the rings hanging on the exhaust port. The simple cure was to move it slightly but honda got a lot of performance having it where it was. When your piston got slightly loose in the bore that was enough to hang the top ring.

[Anonymous]

I've used a few Wiseco kits. My last one (GS1000 1085) purchased in 1998 had a problem, in that the gudgeon pin circlips turned in their grooves, wearing them away.
Consequently, the pins were eventually able to pass through the circlips and eventually one damaged a cylinder wall.
This was after about 10,000 street miles.
The circlips were Wiseco ones fitted correctly, using only my fingers, no tools, so no excuses there.
I contacted Wiseco and although initially positive, ("We stand behind our product 100%") they were eventually useless, telling me to go back to the UK importer. As I didn't buy the piston kit from the importer, he was only willing to sell me a new kit at cost price. (?275, whats that, about $400?)
Wiseco wanted me to ship the whole kit back to the US! Eventually I persuaded them to accept that I could send one piston only as a sample back to their agent in the UK.
I had already sent them a whole load of digital pics, but the response from their engineers was "Derr, gee, I don't know how that could have happened"!
Finally they conceded that there was probably "some kind of material issue", but that as the pistons had done more than a couple of thousand miles, they couldn't help me.
Thats "standing behind our product 100%"? :x
It was the importer who took the hit on a new kit as a goodwill gesture (Vic Eastwood by the way, highly recommended) not Wiseco. They made another sale.
So thats Wiseco; Too fragile for racing (as others have testified), not durable enough for street use.
However I replaced my kit with an older (early 1990's), well used 1085 kit which had already done many thousand miles and was in lovely condition, and it seems to be going fine.
The pistons were a slightly different design, having no grooves on the top ring land.
Maybe some quality control issues have crept in at Wiseco in recent years?
Needless to say, I won't be buying another Wiseco kit.

[Hoomgar]

hmmm, so if I don't get weisco then what should I get for my 78 GS1000? I was also getting the weisco 1085 kit.

[Anonymous]

I wondered this too. I came up with 4 options:

1. Use OEM Suzuki pistons, 1mm oversize and rebore.
2. Use a set of JE or MTC pistons designed for the Kwak GPZ1100/Z1000J which have 18mm gudgeon pins and will fit. They may need modifying.
3. Would Suzuki pistons from the GS1100G shafty fit?
4. Use the Wiseco kit and hope!

[Hoomgar]

Keith used the Wiseco kit years ago and has had no problems.

Not sure what to believe.

[KEITH KRAUSE]

As with anything in this world, you can have bad luck and good luck.
I too, get frustrated when your best efforts don't pay off. What can you do? Nothing in life is guaranteed.

[Anonymous]

True.
As I said I too have Wiseco pistons in there and doing well, and have used them in the past with no problems.
We each have to decide where to put our money.

[Paul]

I was very happy using Wiseco pistons when I was drag racing. I used them for 4 years with no problems.
I didn't use circlips though, I'd heard too many horror stories of them failing, so I used teflon buttons instead.
Also the kits I used were "pro-series" if that makes any difference, I know it did to my pocket, they cost about ?450.00 a set (about $800)! 8O 8O

[cbxchris]

Again contact John at J&E and they will make anything you want. Custom pistons are not that expensive from them. Paul I have tried the teflon and aluminum buttons for the pins on the street. After several thousand miles they will wear a groove in the cylinder. I also used the pro series. The ring lands broke. Arias,MTC and J&E don`t....I used them all. But as I stated under severe loads. Try 35 pounds of boost and 3 stage nitrous so anyone can see that wiseco probably would be fine for the street. But if given a choice I would not use them.

[Inside Line]

I bought a set of Wiseco 1166 pistons last year. 1 was too far out of round to use. They did replace it; though it took 4weeks. Surprised and dissapointed. I heard that Wiseco was concentrating more on dirt bike pistons these days (gotta be a larger market). JE seems to be a popular choice w/drag racers.

[terry]

While we're still on the subject, does anyone know much about "Action Fours" pistons? I bought a NOS set for my old Honda CB750 last year, and they appear to be very well finished.

They're actually a 720CC kit for a Kawasaki KZ650, but at 65mm dia, will take my old sohc 750 out to 836cc, and the domes, although higher than stock, should still squeeze up into the combustion chambers ok. It's interesting (to me at least) that the kit comes with OEM Kawasaki rings and gudgeon (wrist) pins?

Maybe Wiseco should have done a "partnering" deal with the OEM manufacturers and supplied their kits with genuine rings (if possible) and "wrist pins"? :?

[Paul]

I used a set in a 750-4 years ago & never had a problem. 836cc - same capacity. A mate also had a set he was also well pleased with them.
Both sets were Action-4's.

[Anonymous]

wiseco circlips have 2 sides. they can be placed in correctly either way, however the sharper edge needs to go towards the piston and the smoother side needs to go towards the pin. if you get this clip in backwards then it pops out and causes problems. the set I have in my chevy pickup can withstand the 7600 RPM runs on the dragstrip.

best suggestion I can say is buy whichever set you feel fit your needs and install them per manufactures specs and don't alter, if it doesn't go as specified then it is a defect in the parts.

[cbxchris]

The action 4`s pistons I have seen are OEM pistons remachined. They`ve been doing that for years. Actually they hold up very well on the street.