kt250guy Posted August 2, 2008 Report Share Posted August 2, 2008 HI I was woundering what the modifacations to the KT250 were back in the 70-80's the modifacations done by don smith would be nice to know but any would be great to know thank's Quote Link to comment Share on other sites More sharing options...
axulsuv Posted August 2, 2008 Report Share Posted August 2, 2008 Hi ; I personally don't know what mods they did back in the day , but these days you may want to contact Bob Ginder at B&J racing in dickson , TN. He has built one for one of our ITSA members that pulls like a john deer and turns like a bobcat ... I have not a clue as to how he ported the motor , but I do know the bike has Falcon shocks and WES front springs , and I'd bet he modified the fork angle a wee bit . But Bob would be your best source for anything twinshock related here in the colonies ... The Man has a wealth of knowledge and the facilities to put it all into use ... (ie. a shop that can do what ever you dream up or need ) Eventhough he doesn't stock much in the way of fantic parts , with his guidance and some suspension parts , has helped me turn my 83 fantic 240 pro into a machine that can hold it's own at a modern event ... As long as I don't get to carried away ! Glenn , Best of luck ! Just get out and ride the Kt , and make mods as you can/need them !!! Quote Link to comment Share on other sites More sharing options...
kt250guy Posted August 3, 2008 Author Report Share Posted August 3, 2008 I ride my KT almost every day but Im considering building another KT but this one will be super modified just like the factory pro bikes I hope to have the best KT ever built Quote Link to comment Share on other sites More sharing options...
swooshdave Posted August 3, 2008 Report Share Posted August 3, 2008 There are a couple good thread on this forum about modifying the KT. You even responded in it. In addition haven't you talked to Jay yet? He apparently did some modifications "back in the day". Are you going to ride the Honda or KT at Chehalis? Quote Link to comment Share on other sites More sharing options...
kt250guy Posted August 3, 2008 Author Report Share Posted August 3, 2008 Im not sure the honda went BOOM!!! but we rebuilt the motor and so far it's working fine but I don't totally trust it as much s my KT I'd rather ride the KT but my dad might want me to ride the honda so I don't know Quote Link to comment Share on other sites More sharing options...
jaylael Posted August 3, 2008 Report Share Posted August 3, 2008 Since nobody seems to be elbowing their way to the front I will offer a few ideas. In 82 when I built my KT, it was all the rage to cut the tubes out from under the engine, and install a beefy aluminum skid plate with thick rubber pad. I seem to recall a factory KT of Curt Comer, and Gary LaPlante. These bikes used the KX 250 clutch cover, and around 300 cc overbore. At that time I believed the original KT 250 to lack sufficient flywheel effect, so mine had an added weight, which was a disc bolted on to the flywheel. This required a spacer for the mag cover which I had made by a machinist. He made mine out of steel plate around 5/8" thick, and looked like a mag cover gasket from the side view. This requires longer screws. The frame mods involved the previously mentioned skid plate mod, but to improve the handling of my KT as I saw it in 1982, was relocating the swingarm pivot bolt as close to the engine as possible. This shortened the back, thus lightening the front end. I felt this was an improvement. Relocating the lower shock mounts farther up the swingarm was a very common mod, which I think requires removal of the chain oiler stuff. This gives quicker steering. I ectimate we moved them forward about 2 inches, not a great deal, this also gave softer rear suspension which had slightly more travel. Footpegs are located well, just need some weld on peg jaws, like from works connection. I made mine from scratch. Stiffening the forks with KX fork springs or air caps (gasp) will be necessary. I can't recall for sure but I think I shortened my steering stops slightly also. This is touch and go doing this so it must be done in small steps with test rides between. Very sketchy territory. I used the stock center box with a longer more convoluted header pipe and had also renovated the front downtubes into a single squre front down tube 1 1/4" which split into two above the exhaust port. Quote Link to comment Share on other sites More sharing options...
kt250guy Posted August 4, 2008 Author Report Share Posted August 4, 2008 It sound like you replicated a SWM frame If you put KX springs in the forks do you still use the stock caps? Quote Link to comment Share on other sites More sharing options...
fivemeister Posted August 4, 2008 Report Share Posted August 4, 2008 Probably next best thing to asking Don Smith (RIP) is to ask Richie Sunter who was also a KT works rider and is still about in the Yorkshire centre. I would think he's easily contactable through the Richmond MC. Quote Link to comment Share on other sites More sharing options...
jaylael Posted August 4, 2008 Report Share Posted August 4, 2008 It sound like you replicated a SWM frameIf you put KX springs in the forks do you still use the stock caps? Yes, it was a very direct attempt to get the KT to behave more like an SWM. How astute of you to notice. I used 74 kx125 fork springs, but plugged up the hisser holes. If I remember right, I also used 13 1/2" s&W shocks w 60/90 springs. Forward mounted and with the relocated swingarm pivot, the suspension was good. Quote Link to comment Share on other sites More sharing options...
kt250guy Posted August 5, 2008 Author Report Share Posted August 5, 2008 Did you do anything to the motor besides the flywheel weight Quote Link to comment Share on other sites More sharing options...
jaylael Posted August 5, 2008 Report Share Posted August 5, 2008 No. I think the KT has one of the best running engines for trials I've seen among the vintage bikes as it is. Quote Link to comment Share on other sites More sharing options...
dgraf Posted August 5, 2008 Report Share Posted August 5, 2008 are there any pictures of this modification(swing arm and frame)? Quote Link to comment Share on other sites More sharing options...
swooshdave Posted August 6, 2008 Report Share Posted August 6, 2008 are there any pictures of this modification(swing arm and frame)? I don't think they had cameras back in those days... Quote Link to comment Share on other sites More sharing options...
jaylael Posted August 6, 2008 Report Share Posted August 6, 2008 Sorry, no pictures exist of this bike. I was twenty two tears old. Now we're in the digital age and I still save film like it cost a million dollars. The bike was ridden in trials for a short time by it's next owner after me. In 1987 on a trip back east, my wife and I stopped off briefly in our old home town, Gillette Wyoming. I saw it leaned up against a fence out in the rain and snow, it's green plastic tank had been turned a gastly whitish shade by the unrelenting assault of the elements. It's wes aluminum rear muffler was corroded and the poor thing looked like it was ruined. Of course I wish I had it now. Quote Link to comment Share on other sites More sharing options...
swooshdave Posted August 6, 2008 Report Share Posted August 6, 2008 it's probably still there. Quote Link to comment Share on other sites More sharing options...
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