I just purchased an 87'kdx200 and I am having problems with the back brake locking up. has anyone had this problem and found a cure?Or could it be possible that the pads are worn to the point that the spreader pin is hanging up sideways?
You may find that the drum is worn beyond spec, requiring greater travel of the shoes to contact the drum. If this is the case, the rubbing block may travel beyond the point of no return (on the inside, where it contacts the shoes forcing them apart).
Check the inside diameter of the drum with a set of calipers, and compare to the maximum wear limit.
This problem was just one of the reasons why I uptraded to a disc brake model.
Yeah been there done that on my old DT200. Can be done real cheap with a bit of engineering.
Take the rear wheel & make a plate to drop into the edge of the hole for the drum (where the brake plate almost rubs). Loosen the spokes & weld it in place. Re tighten spokes when cool.
This plate can be drilled & taped to take a donor disc. I found a small road bike one with adequate dishing to line it up nicely with the calliper. The calliper is also from a small roadbike (but could use your old front kdx one after you graft on a twin pot, but that’s another story).
You make a plate to bolt the calliper mount to & weld it to the (steel) axle spacer. This plate has a slot in it to match up with the swingarm to stop it rotating.
Then you fit a master cylinder to the brake pedal & you are away.
Lost interest yet?
You could go a bit ‘bush’ & get a hardened dowel of the type one might find on a 4 stroke head to barrel, or maybe a side cover. Separate this & slip it over the non moving pin of the drumbrake spacing the pads out a little. (I never said this) You may need to adjust the pads in to get it past the ridge of the drum then readjust, or file the ridge down. (I never said this either). ;)
thanks for all the advice guys but sometimes it's the littlest things that are overlooked!It turned out that the return springs on the pads were to weak to do their job properly.I thought what do I have to loose by putting new ones in because I tried everything else and BINGO they work fine now Thanks Everyone!! I love this sight it's very helpful and it's all about pitching in so we can all enjoy riding are bikes after the helpful fixes!
Actually I retrofitted a better drum to the 83 KDX front. I used a drum off a 70's vintage non enduo yamaha 250. I had to machine an adapter and make some wheel spacers. The axle was the right diameter and the I used my KDX cable. I also machined the yamaha hub a little. Now it stops! I had all OEM parts and it was terrible and wore out quick. The Yamaha brake is awesome and lasts longer, I can actually lock this brake up in the dirt and sand.