It's too bad we have so many ignorant, illinformed, and stupid people on this forum, who don't let the facts get in the way of their biased interpretation. The regulations, while influenced by the CARB, are actually formulated by the EPA. Read the link to "nevadawalrus" posting on the PERR website. Bob has been around more than 40 years and has forgotten more than most of the bloviating ignoramuses will ever know. Bob used to participate in this forum before he became disgusted with the dive to the bottom. The PERR website is more for professionals. For those of you old enough to remember, people were sure that the Calif ARB and the EPA had ruined the automotive market in the 1970's and 1980's. That was when Detroit (and the imports) had to respond with lower compression, AIR, exhaust recirc, catalytic converters, and the rest. Guess what? By the 1990's the car industry had regained most of the performance of the 1960's at much lower emission levels. By the 2000's horsepower ratings were available which exceeded even the most thinly disguised racecars put on the street in the 1960's. Just in case you think I'm one of the treehuggers with a Sierra Club card, I used to drive a Taurus SHO which I consider one of the early modern supercars, and now have a BMW M5. With a 500hp V10 it will run with any 1960's car sold off the dealership floor, including the Street Hemi and the L88, and has the numbers to back it up. I get 15mpg and am completely unapologetic about it. If I need better mileage, I drive my F350 dually with the 7.3L diesel, Here is a link that might be useful: PERR Website, Third Comment

My 1999 10323 had never noticably surged after 5 seasons of mowing and I did no special maintenance (I.E. add an external filter) until a couple of years ago. However my 2003 10424 surged madly from the day I bought it (brand-new) in May 2005. Since it was NOT my first Duraforce experience, it drove me nuts. Thought maybe it had something to do with the 10323 being self-propelled (always has a drive-load on it) where the 10424 is a push model just spinning the blade. Don't remember if I ever tried swapping carbs between them to see if I could get the one to start surging and the other to stop ... this would have been a good experiment. Then I found this web site and the long "Duraforce How-To" threads, and saw I was not alone. Jetting the 10424 (1 drill size up on main jet if I remember correctly & Suzuki Pilot Jet) stopped the majority of it's surging and lowered the operating temperature. I soon followed suit on the 10323 just to reduce the operating temperature. Later I re-jetted two 10247's ... a good friend of mine and his next door neighbor. Kind of odd they had identical mowers; I believe one was a 1998 and the other was a 2001. These being the Steel Deck Push Model they noticably surged, but not as bad as my 10424. My neighbor accross the street from me has a 2002 10552 that I've never heard surging. He bought it used in 2005, so I can't say if it had been tweeked by someone prior ... it does however sound like the RPM is higher than it should be. I'll have to grab it from him some day and check the RPM ... if ok, I'll have to see if the jets have been altered at all. Doug

Ebay has some good people selling those different type (splined, Pac-Man, D shape) diaphragm carb mixture screw head adjusting tools at lower prices. In a pinch, I have used an automotive type 22 gauge wire connector, forced it down around the screw head and turned them that way. Occasionally they just are in too tight for that to work, but ring terminal connectors (plastic) and female spade connectors work well!

"H.Kuska answer. Because "clastogenic" does mean "will cause cancer". A clastogenic compound "may" cause cancer. It also "may not"." Actually, "clastogenic" for biologists (which I am one) means inducing breakage or disruptions of chromosomes...aka, breakage, deletion, and addition mutations. Maybe we wouldn't have so much denial about the issue if you could make that connection based on what I was talking about and the meaning of the word rather than focusing on how it may cause cancer. Your lack of understanding of the subject is jumping to strange conclusions. This is getting extremely silly. If you're going to Google a bunch of stuff, cut/paste it, and demand scientific accuracy from others...at least know how to read and use the information you're trying to use for the sake of your own scientific accuracy. If you don't understand a word, use the same Google search to find out what it means. ...and besides...this is just a distraction from the point I've been trying to make about the study you posted...that using in vitro studies and drawing conclusions about a whole body organism using single-cell measurements and concentrations are not valid to say something, quote something, or stand by something such as "100,000 times the concentration needed to cause cancer." That is the point that's important to the discussion at hand...how the "100,000 times" alarmist message based on an in vitro study is utter scientific bull. The example I gave merely gives an example of how you can't scale like this based on an in vitro study of a single cell type. There is no "100,000 times" effect in play. That's not how you treat an in vitro study and concentrations used in direct cell experiments vs in the real world...and that's before you get to pathways for access vs directly injecting or saturating a substance straight into a cell. If one is going to critique and use scientific literature, it helps to understand what you're reading and the "in house" language it's written in. While you may be able to break down an explanation about how a number of chemical catalysts can break down a substance into a string of chemical compounds based upon your scientific background...and I probably wouldn't be able to...you're not very good at biological science. We are both scientists, but we're not jack of all trades. A mechanic that can fix a Volvo engine isn't automatically qualified to fix Blackhawk helicopter engines just because they're a mechanic. This post was edited by nc-crn on Thu, Jul 4, 13 at 17:35