Hi Guys, I was the original owner of said busted DRZ. I feel I need to interject here and add my 2 cents. Roost me and cover me in dirt if you must. I had that bike for 10000+ k's NO PROBLEMS. Eventually the big end went south, and fragments damaged the cylinder. I did all my homework, and research and decided to go with the 94.5mm Wiseco Big Bore Piston kit. Now, what happens in the workshops behind the doors, and between suppliers and workshops I, am clueless.
First let me say, that whether it was a 440 or a 400 or a 420, the bore size did not contribute to the piston sezing, I would look at the oil pump, and type of oil, and also the level of the oil.
That aside. I requested the Hi Comp 13.5:1 94.5mm Wiseco Piston. 92mm or 420cc Kit was never in my research or thoughts, trust me, I would not go halfway. I never saw the piston. The workshop could have:
A - received the 92mm piston accidentally, and just sent it off for plating, without checking size etc, and just did the install.
B - The company in Joburg, who did the rebore an re-plate, got a piston mix up somehwere.
The Bike ran stronger than ALL the other 440 Kitted DRZees, so I had no reason to doubt that it was not as specified. I have no idea how the owner after me maintained it, but I changed oil and filter every 1000 kilometers, it was ridden to work once a week, and sunday rides with Cobie and the other DRZ owners.
I really feel bad, that it is only 420 Kit, even teh workshop, as a "gift" to me, being the first 440 SM in Cape Town, had the Graphics Kit made up staing 450, as we were under the impression it was a 440. Either way, and honest mistake or oversight was made somewhere. Cobus's 440 is still going very strong with almost identical mods, and he does way more mileage than I ever did. The workshop owner happens to be a good friend of mine as well, and would not purposely mislead me, especially since the ENTIRE engine rebuild cost me R11 000! No expense was spared, for the small difference in cash for the 440 and 420 Kit, I never even consdiered, or heard of the 420 kit. All my research and homework was from information I got from Eddie off Thumpertalk. I would not have gone half monty.
Cobus, Rudolph has the stock 400 cylinder and piston still, perhaps he will sell it?
My sincerest apologies for the misinformation of the piston size. If it's any consolation, if it is a 92mm and it was the strongest of all the modded DRZ's here in CT, you still have 2.5 mm to spare on the bore, and another 2-5 HP to gain from that machine. I sold this bike in March this year, with a very sore heart. I will take it up with the workshop, and see if I can find any more info. Even if it never would have come back to me, or anyone not known the history of the bike, I feel that I need to clear up any doubts of being misled here...
Lastly, whether it was 400; 420 or 440, would you still have bought it? When bikes are modified, there is a little more risk of failure, no matter what bike it is.
Once again, my sincerest apologies. Hope you get it up and running soon.