molochnik

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About molochnik

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  1. I've used the entire assemblies and rebuilt stock cranks with their rods. I've either been doing it right or have gotten lucky. All told, at least a half-dozen of the assemblies and a bunch of rods for rebuilds. Some for my bikes, some for customers. No failures I'm aware of. The only thing I can pick at is that I do check the new assemblies for runout. Some have been dead on, and some haven't but were still within the tolerance called out in the book. I straightened out any of the ones that were out to dead-nuts or as close as I could get. Things do change though, so it's possible quality could be slipping. I don't think I've done a bottom end for 8 years.
  2. Just out of curiosity, in regard to reckoning the intake hole vis a vis piston size, how might the formula change if one has a twin cylinder; more precisely, a parallel twin where the pistons rise and fall together, but only one is pulling air on a given rotation? Same deal - one piston's area? Double that? 1.5X piston area? Just has me wondering about my XS650. I have lots of room for a custom airbox, but it may not be so necessary on pavement (for the sake of dirt, etc.) - goes fast enough now.
  3. Do these older models have, or are supposed to have, a fan? Your mystery wire may be for that...especially if the fan is gone.
  4. Ugh; during the building boom out here in the AV back in the 2000s, there were nails all over the road. Often seemed to be in intersections where a box would likely fall off of a truck pulling away from a stop sign.
  5. When I began riding my YZ250 in flat track trim on supermoto tracks, I was experimenting with tire pressures that were too low to responsibly post on a forum. This was with my cheap IRC tubes I was buying from a chopper shop. The tires got hot, but they didn't go flat. With proper supermoto wheels/tires I ran the same pressures you are and all was fine except for the one flat mentioned a while back. This was in the SoCal desert with sharp edged rocks and all the other crap out here. I always applied baby powder liberally and if I did use any lube, it was the vegetable based lube I got with my No-Mar tire changer. If you're using something like dish soap, it could very well be drying them out and causing these mystery flats. I would be astonished if the mechanics you're dubious of would be able to pinch the tube and it would still hold air...for a while. I'm with the dudes who are suspecting you've got some spoke ends poking the tube, or perhaps a chewed up wheel/stem hole.
  6. Tire balancing, fork health, and even the aerodynamics are good suggestions, however, be sure your shock isn't tired as well; whether a supermoto or a roadrace bike, you'll get tank slappers if the charge is low on the shock. I had an 05 SMR 525 and didn't have any wobbles. While it had the adjustable offset trees, I never messed with them.
  7. I dunno one way or the other, like I said (or implied); I just sorta assumed it was for the transmission. Triumph used bumpers in their clutch baskets at least as far back as 1959. I guess it would be worthwhile to know if the OP was asking in reference to cush drive or quality of the stock hubs...before we get off topic arguing cush drive,
  8. The only difference I can think of in regard to a dirt hub vs a street hub is the cush drive one finds on most chain driven street bikes. Some mfs have put a cush drive rig in the clutch basket, and Harley uses (or used) a compensating sprocket on their big twins. I'm not sure what they did with Sportys before belt drive...but I digress. You might hear cautions about the transmission taking more of a beating w/out cush drive on pavement. I dunno if that's something to be concerned about. Lots of dirt bikes have been laced up with 17s and had slicks put on them; I did it with my 02 YZ250 and if memory serves, my KTM SMR didn't have a cush drive. Granted, we're talking about a racing configuration which is often sub-optimal for street use. I didn't put a lot of time on the KTM, but I did with my YZ, albeit on kart tracks and road courses and copious desert riding. I didn't notice any transmission troubles nor abnormal wear when it was opened up. I've put a chain on a 2000 Sporty rigid I put together and wondered if I would end up with any trouble...but did it anyway. Lots of people do it with Harleys since the belt rigs are awfully expensive to replace.
  9. Also, FWIW, I'm running a bridgestone 150 S11 EVO on the rear of my DR that I converted. I don't remember what I used for a tube, but it wasn't anything special. I only ride it on the street so far...just haven't had reason/desire to go offroad. No problems in 2000 miles.
  10. Back in the early days of supermoto here in the U.S. I used to go buy 16" tubes at an independent Harley shop. I would just get the ~$8 IRC tubes with a center stem. I'd get the 5" ones for the rear and the 130/90 size for the fronts. Ran them in slicks, rains, DOT race tires on kart tracks and in the SoCal desert. I only ever got one flat and it was out in the desert - rain tire on the front. Never really discovered why. So I never bought expensive tubes and got by fine. I'd either use the extra wide rim strips for Harley wheels or duct tape. I agree with all the folks who recommend investigating your wheel.
  11. funny. I thought the same thing, but that's what the Suzuki manual says.
  12. I did a quickie measurement with my protractor this morning and it looks like the rake, as modified, is around 30 degrees. I took a look in the book and it lists the stock rake as a whopping 43 degrees. I suppose that's to get the geometry right with a 17" rear and a 21" front. I put a 1/4" spacer in the shock when I revalved it and moved the lower eye of the shock to the factory-provided "lowering" position. I lowered the front end about 3/4" and with the 17" front, it has come down quite a bit. I guess that's why converting my YZ to a supermoto didn't yield the same radical changes since the chassis started out with a 19' rear and the 21" front. That bike worked pretty nicely. A slight understeer...very slight. This DR is prone to some serious oversteer. I have to keep widening my line through sweepers. I agree with both of you guys in general, and while I haven't given any thought to swing weight, I'm not sure it is much of a factor with these bikes...or I'm not that sensitive to it. Getting the rake kicked back out there will certainly get things back to more normal characteristics, but I'm embarrassed to say that I have an aesthetic issue with there being any more rake. That's why I began to contemplate the tree offset. I ran across some pretty cool gizmos at Cheney Engineering; that presumably address this issue. They convert a leading axle to a location just below the bottoms of the forks. No big deal for a dirt tracker since the front brake would have to be re located, and it would just be a day or two on the mill, but I think machining a set of trees would be easier. Thanks for the inputs!
  13. I'm considering turning my DR650 (2016) into a road race track day bike. Having already put 17" tires on front and rear for supermoto/canyon duty, the trail has become so short that it is not very hard to tuck the front, and it is just on the stable side of being prone to tank slappers. I kinda expected this, and I know this is road race content in a dirty area of the site, but I was hoping to pick the brains of the engineering/experimenter sort. What downside can I expect if I were to fab up some different trees with less offset to bring the trail back into a more acceptable range? Anybody experiment with this? I can continue lowering the rear to get things back in line, but I don't want to lose cornering clearance. I've seen H-D road kings with negative offset. Any thoughts?
  14. I ran a 5X17 Behr on the rear of my 2002 YZ 250 2t. Depending on the tire I had to trim the right edge with a razor blade. If I remember right, this was usually necessary with rain tires. When I ran Maxxis slicks I don't believe I had to do anything to them. I always used a 160 rear. The front *shouldn't* be a problem, but I can't say that Kwakas have any more or less room than my Yamaha did.
  15. I would expect that you would be fanning the clutch quite a bit on a 125 at 190lbs. So you may find yourself doing more clutch maintenance than you would on a 250 - 4t or 2t. It's a shame that an older 2502t is out of reach for you financially; it would probably provide the best of everything in terms of power, affordable maintenance, and general satisfaction. It's not a big deal to detune a 250 2t, and keep in mind that as you get more comfortable on the 125 you will likely ride it harder and harder thereby shortening time between overhauls. 125s are a lot of fun, but they are best for jockeys and not larger types. A 250 2t will give you lots of room to grow.