michaelmoore

hello Ross, I've got one of the paper shop manuals. I think it can also be downloaded from the KT/KX site. I wouldn't have guess the stock ignition would fire a .075" spark plug gap, especially when chugging along at very low RPM. .024-.028" is the factory specification. If you can get it to do it, wider gaps are usually better. The forks on my bike do top out with a noticeable clank (perhaps more felt through the bars than heard) sometimes. I'm going to look more closely at sag when I get it running. I'm about 200 lbf when ready to ride and I suspect the target rider was more in the 170 lbf range. Some stronger springs might be in order. My bike was on pre-mix when I got it, and I think a lot of KT owners have gone that route. I got a box from Buchanan's yesterday filled with hubs, rims and spokes. The front hub is now cleaned up and ready to accept new wheel bearings. I'm going to try and get the rear wheel to that point tonight. cheers, Michael

I wish I'd known about that swaged section being what held it together. Removing that sounds like far less aggro than mauling it with a big hammer. I'll have to give that a try and make some more with different sizes of plugs. The one on the left is threaded while the one on the right is brazed in place. I can't recall why I made the brazed one so long, but there must have been a reason. I'd think that stopping the piston more towards midstroke when it is moving farther per degree of rotation might be a little more accurate, but the difference is probably splitting fractions of a degree. cheers, Michael

Here are a couple of piston stops I made from old spark plugs. Getting the ceramic out of the plug body can take a bit of doing, and when you are hammering on the ceramic to break it be sure to wrap a rag around it as if you don't you'll have bits of ceramic shooting all over the place. Eye protection is recommended even with the rag. cheers, Michael

On a bike where the plug hole is not parallel to the cylinder centerline I'd do one of two things. Preferably, I'd hook up a degree wheel and use a piston stop to determine TDC and then set the timing with the degree wheel. Otherwise, I'd pull the head, set up the dial indicator to run parallel to the cylinder bore, and then set the timing AND make a mark on the flywheel so that I could duplicate that setting in the future. Most pistons have several degrees of "dwell" at TDC that are very difficult to distinguish with a dial indicator. I'd much rather use a piston stop and a degree wheel to find TDC. Even if I was doing the second method I'd use a piston stop and degree wheel to find TDC first, and then set up the dial indicator. But if you know the stroke and rod center-center length you can ditch the dial indicator and use the degree wheel (and mark the flywheel afterwards). cheers, Michael

I cut the outer pivot support plates off today. http://www.eurospares.com/graphics/trials/KTdamagepivot.jpg shows the heavy scarring on the insides of the plates from the ends of the swing arm. http://www.eurospares.com/graphics/trials/KToldweld.jpg In the middle of the photo you can see a weld that was there on the 3/4" frame tube when I got the bike. It is pretty much at the top of the doublers they added for the pivot plate and footpeg mount. I think I've seen at least one other KT with a weld in that area so it might be a spot to keep an eye on. cheers, Michael

Gerard Kane. He talks about loaning his TL125 Highboy chassis to Richard Jordan at SMP in his "Signing on" editorial in CDB Issue 6, page 3, paragraph 3. cheers, Michael

It looks like the bronze bushing conversion is not going to be a "bolt on" deal (as with the bronze bushings you used to be able to buy to replace the plastic bushings on RD350s) since Kawasaki didn't leave a lot of room for bushing thrust flanges but let me know if you have something that I might be able to assist you with. I won't promise that I'll be able to help, but I often know people who can take care of odd specialist problems. The porting mods (and squish/timing modifications) might be more important than the long headpipe exhaust. To my frequent chagrin, I'm not a very sensitive rider and many times I can't detect subtle changes so I have to go on theory. But the head/cylinder/timing mods with the stock exhaust seemed an improvement to another rider who rides one line higher than I do and who also has a KT250. I suspect that for novice level riders extra flywheel weight would be useful. I don't see that happening without a new mag cover or a spacer for the stock one, depending on if you do a weight that bolts on to the end face of the flywheel or that is a ring shrunk onto the periphery. cheers, Michael

There's something to be said for having the competitors score each other, especially if you have a rule that you can't have someone score you more than once per loop so that there is little chance of two people scoring each other with cleans all the way through. But maybe some people have a lot more friends who'd be willing to fudge the score than I do, and so could come up with nothing but cleans. Another rider is going to have a good idea if you've really stopped or just momentarily stopped "pressing on regardless." And if the person scoring you is competing against you the likelihood that you'll try a fiddle movement seems somewhat reduced. I very much appreciate the people who put on trials (or roadrace or MX) events that I can ride at. It is no doubt a lot of work and aggro and I'm glad I don't have to do it, and I'll give them a fair bit of benefit of the doubt if that seems warranted. But there's a difference between "everyone trying their best to do things right but proving to not be quite up to par" and "half the observers giving their friends/heroes breaks, or the promoters saying "who cares how things were scored, we decided how the trophies would be handed out before the "event"". I hope the latter case is never the case. But from some of the comments I've seen at Trials Central in different threads it sounds like it might happen now and then. Bike eligibility is a whole 'nother can of worms. DIY modifications/complete bikes is an interest of mine and I've got a lot of material from the early/mid 1960s on that shows me that there has been a lot of very interesting things done in sheds across the planet. You can pick a "period" modification from 15 different period bikes and add them together to have a thoroughly modern "period" bike. Pugeot had DOHC 4v/cylinder engines in the mid 19teens (a friend of mine has one of the Pugeot Indy cars at his vintage race car shop and I've gotten to look at the engine) and there's very little new under the sun. So you need to have some sort of "period bike" template to use. If you can hold up the template and the bike behind it is a pretty close match, it is OK. Too many Pre65 bikes seem to fit behind a "late 1980s" template and not a "mid 1960s" template. This is not a problem only with trials, classic MX and RR have a similar problem. Some organizers will say "screw the non-period bikes, we're drawing a line at 98% original and if we don't get enough entries we'll not hold the event", some will say "85% original is good enough, and we'll accept "like design"" and others will say "we'll take anyone that seems to be even remotely possibly maybe eligible in order to get the event going and hopefully later we can tighten up eligibility and put on the event with real period bikes as we advertise." Each approach has different pros and cons. Not all situations are the same. But if you have published rules it would be nice if you actually follow and enforce them. cheers, Michael

I've got a spare cylinder and a spare engine, though that spare engine seems to have spent a lot more time out in the weather than was obvious from the photos on eBay! I recently picked up a NOS spark box, which was easy for me to justify. I may have gotten the last KT250 rod kit out of Kawasaki, but you can use the later KX250 rods if you add a spacer under the cylinder to offset the slightly longer rod. I didn't use any parts of the stock main exhaust on my new system, only the tail silencer/spark arrestor. But raising the exhaust port to increase the exhaust timing up to near the general trials porting numbers (as you can see on the KT250 page of my website) made a difference with the stock exhaust, so you might want to give that a try. If you are able to weld you can build a new head pipe. Or if you are able to fit things up and have a friend who can weld that will work too. The welding usually takes a lot smaller portion of the total time than the fitting does. I'm going to be interested to see how I like the bike after I add some more flywheel mass. I like dirt bikes with heavy flywheels, they seem to fit my riding style. Are you in the UK or here in the States? cheers, Michael

Isn't that "closing the gap" ugly? It reminds me of the swing arm on the SF750 Laverda I had, where tightening up the axle pulled the axle plates in a good 1/4" or so. For your silentblocs you don't need any kind of special hardened shim as spacers so I'd recommend you fill as much of any gaps you spot with whatever 12mm or 1/2" ID washer that falls readily to hand. It is unlikely to be worse than letting the frame be significantly distorted. Even if you only fill 80% of the gap that is going to be an improvement. Make sure that the swing arm proper doesn't end up rubbing on the frame if the center bush is pushed too far to one side or the other. 40mm seems a lot more likely than 39.5mm on the center bush length. But I've seen too many oddball measurements to presume that designers went for the obvious one. Sometimes motorcycles seem like dancing bears. The amazing thing is not how poorly the bear dances, but that it dances at all. cheers, Michael

Possibly because most people have only seen pictures of the Highboy frames and not ridden them and therefore work on the presumption of "if Sammy Miller put his name on it, it must be good." I'll admit that I've presumed the Miller frames must handle well. I've read articles/comments in the magazines or in books that raved about how wonderful they work, and the comments above are the first I've ever seen saying they weren't very good. I know you can't trust the journalists to give the straight scoop all the time (though one would hope that they would) but if that is all you have to go on, along with Miller's reputation for having developed bikes for Bultaco, Honda and others, then you'll probably figure that the Highboy frame is just the thing you need to make over your old bike. Maybe it is one of those situations where the Highboy suits SM to a "T", and sucks for everyone else who lacks his level of talent (and his preferences for bike set-up)? Things that are wonderful for an ace rider can often be calamitous for someone operating at about 50% (or less) of their skill level. On the roadrace track a classic 250/350cc single feels pretty comfortable for me. The last thing I need is to be plopped down in the seat of Rossi's Yamaha and told to "go for it." That may apply to trials where a 1974 325 Bultaco is great for me but Bou's bike might see me make more errors if it needs a firm and skilled hand on the bars that I'm not able to provide. cheers, Michael

I think I've got a decent idea of how things often work in the real world of motorcycle competition. I've raced in a few AMA BoTT nationals and I've got friends who've been associated with factory teams and I'm well aware of how "name" riders can get a pass on something while a privateer gets hassled. My local roadrace club (American Federation of Motorcyclists - at over 50 years I think it is the oldest strictly RR organization in the USA) seems to have little trouble applying track and equipment rules evenhandedly, which is not something that can be said about many periods in the AMA's history. The promoters/organizers have the responsability for running the event. It is their responsibility to make sure the people they engage to help them do that (whether volunteers, paid with lunch and a free entry for the next event, or paid with cash) do their jobs correctly. Even if you are a volunteer, you are still working and if you can't do the work correctly you should be replaced by someone who can. And if you can't get enough competent/trustworthy people to run an event, you don't hold the event. If you've got published rules that are being ignored or applied haphazardly you aren't holding an observed trials competition. What you are doing is hold an observed trials "track day" where people can come and pay their money to ride sections other people have set up. If you want to be in the business of hosting trials track days, just do that. You might actually get more people to come out than you would if you hold a "competition" event where some people get to cheat and others don't. Someone has to take some responsibility. The promoter is the one that is taking in the cash, and it seems they need to deliver what they said they would do. It seems like the customers (the riders) also have a responsibility to not patronize events that are shoddily run. Why reward someone for doing a bad job? It isn't unknown for people to get fed up and set up a new club or organization to run their own events. Sure, then they get stuck having to do the work instead of letting the other guys do it, but if you are annoyed enough by the way the other guys do it you'll bite the bullet. If it is too much trouble and you'd rather just go to the other people's event and bitch about what a bad job they are doing, perhaps the bitching is out of order. Don't get me wrong, I'm as happy to bitch about things as the next person. But I try not to get into the mode of "not only do they serve horrible food, their portions are are also too small." You either put up with things and largely hold your tongue or you put your money (or time and sweat) where your mouth is and do it yourself. A lot of times things aren't so bad that you can't put up with them and bite your tongue. I've done that and I expect there will be plenty of occasions to do that in the future. Everyone gets to make their choices. cheers, Michael

What's the problem there? It seems like the organizers will have an observers' meeting before the event starts, and they will tell everyone "this is a no-stop trials so a stop gets a 5" and then stops get a 5. If you are going to have the observer in Section 3 giving out 5s while the observer in Section 7 is turning a blind eye, I'd think you'd have a lot of justifiably unhappy riders making it clear to the promoters that they are falling down on the job. If every observer is an independent contractor, you may as well not have any observers at all, and just let everyone write down their own score on an "honor" system. And I'd think that events where the rules enforcement is a joke will see a drop off in attendance because there's no sense competing on an uneven and variable playing field. I have no problem protesting people who aren't following the rules. It seeems to me that anyone who turns a blind eye to cheating is not much better than the person doing the cheating. Either the rules are good enough for everyone to ride by, or they aren't good enough for anyone. All or nothing. Or is this a case of "he's the famous Joe Blow, so we always let him cheat?" There's nothing like obvious favoritism in the rules enforcement to leave a bad taste in everyone's mouth. I think a case can at times be made for enforcing the spirit of the rules instead of the letter of the rules, but if that is going to be a regular occurance than the rule needs to be rewritten before the next event so that it actually says what it was meant to say. Trials seems like a pretty simple sport to make rules for. It isn't something like cricket or baseball where you can spend months learning all the ins and outs of the rules of play. Rules is rules. "No stopping" seems like a very simple rule that shouldn't be a problem to enforce. It certainly didn't seem hard to enforce back in the early 1970s. cheers, Michael

Checking the sag in the stock fork springs is on my list of things to do when the bike goes back together. I've seen mention of using aftermarket TY fork springs but I haven't played around with the KT forks as I suspect that just replacing them with a Bultaco fork would be more of an improvement. If your outer support plates pull in and bind on the swing arm you can probably just insert some small shim washers either between the center bushing of the silentbloc and the center tube in the frame, or instead out at the outer supports, whichever seems most appropriate. If you look I suspect you'll see slop on one or both sides of the silentblock bushing. If the frame/swing arm/bushings had been in great shape I'd probably just shimmed things up. Since they aren't, I'm not going to try and buy new bushings from Kawasaki AND deal with the other damaged parts. If a 1-2.5mm thick 12mm ID washer fixes things up for your bike, that seems like a pretty easy fix. Are you keeping the stock exhaust and doing more of a restoration, or are you going to do some modifications? I don't remember if the info on my exhaust on my website includes any dimensions, but I've got the exhaust here at home and I'll try to remember to check and add dimensions if they aren't there. I'm pretty sure the porting changes are documented on my site. cheers, Michael

I think this photo of a Gollner KT250 used to be on the KT/KX page, but I couldn't find it there any more. You can see the single bolt from the frame to the front mounting plates on the engine. If the frame flexes (which I think it will) that might be a little less stressfull on the engine, or at least it seems that way. cheers, Michael

If you could do the length of the central tube welded into the engine mount box too that would be appreciated. I'm getting 4.375" (which since the outer support plates seem to be right at 7.5" doesn't surprise me, sometimes inch measurements creep into metric bikes) but the ends of that tube on mine are also obviously suffering from wear. Metric or inch dimensions are fine, I can work with either one. The problem is that the center bush in the silentbloc bushing is too short, so as you tighten up the nut on the spindle the outer plates are drawn inwards (distorting the frame) until the center bush bottoms out on the tube welded into the frame mount box. On my bike, that doesn't happen until the outer support plates are pretty firmly clamped on the pivot tubes on the swing arm, which means that movement of the swing arm doesn't happen without a lot of extra force being applied. To get enough thickness to the thrust face of the bronze bushings I'll be making I'll need to cut off the outer support plates and move them over a bit. Whilst I think of it, my bike came with a glob of weld on the outside of the left pivot to seat rail tube just above the doublers for the outer support plate. I'm now wondering if the extra stress from pulling the frame inwards might have caused a fracture in the past. I have hopes of getting into the garage tomorrow so I can cut off the outer plates and start fitting up the new ones. While you have your calipers out you may want to measure at various points on the pivot bolt. The spots under the bushings on my bike are about .002" undersize compared to the part in the center. cheers, Michael

I'm going to trim the front downtubes on my KT right below the lower engine mount, at minimum. I may go to a set of plates bolted to the front mounts with a single bolt to the down tubes as on the Gollner frames. Take a close look at your swing arm pivot for the problems I've outlined in my KT thread. Actually, if your frame's silentbloc bushings seem to be pristine could you measure the length of the central bush? I can't tell if it should be 39.5 or 40mm as both of the bushings on my frame were worn. It isn't a big deal as I'll just make things to fit, but it would be nice to know what number Kawasaki was using in setting things up. If you run a rear damper with a spring that runs farther down the body past the level of the rear chain be prepared to have to space the left damper out away from the chain for clearance. In the early 1970s I saw one person refer to the Kawasaki green (as used on the H1R roadracers) as "gator belly green". cheers, Michael

But AHRMA is all about having a gazillion classes. They just added a 100cc MX class (after lots of pushing from the Hodaka guys) so it is possible to get them to add things. And with trials you aren't trying to find space in the schedule for another grid for a new race, all you'd be doing is seeing some more riders in the queue at each section. The evoT bikes don't appear to be a huge leap forward from the 1978 bikes. It isn't like going from 4/7" to 12" of suspension on an MXer. Would having an evoT bike see a 3 or 2 line rider suddenly cleaning everything on the next harder line? It seems unlikely. My one ride on a modern (early 90s GasGas I think) bike didn't see me feeling like I was suddenly ready to ride harder obstacles as it still depended on me pointing it where I thought I wanted it to go. cheers, Michael

Tony, do you know if an "evolution" twin shock class has been proposed to AHRMA any time recently? We've got evoMX classes and evoTrials would seem to be a lot less bother as the sections wouldn't seem to need to be changed as you largely pick your line based on rider skill. cheers, Michael

That's pretty much life with a unit single. If you aren't already aware of it http://www.b50.org/ has a lot of very useful information. cheers, Michael

You might try Matt at www.speedandsport.com cheers, Michael

That's my goal, to become a "dreaded prior owner." My bike wasn't exactly pristine when I got it and I had to deal with some DPO issues. I'd be happy to go metric on everything. An English friend of mine living in Spain was getting a used lathe and I reminded him to be sure he got all the threading change gears so he could cut both inch and metric (I presumed he was getting a metric machine). He replied "why would I want to cut an inch thread?" But all the cool MilSpec aircraft types of fasteners are inch, and they are a lot nicer to use than "commercial/industrial" metric stuff as you can get the grip length you want without having to chop 3/4 of the excess threads off. If I get it fixed right any future owner is not likely to have to deal with any of the stuff I've changed, as it won't be a problem for them. Anyone who wants a stock bike needs to not buy something from me. I've not owned many new bikes (only 4 that I can recall) but most of them didn't stay stock for very long. There are just too many stock parts that benefit from being replaced, and I'm far from the only one who did that replacing "back in the day." I am definitely spending time making plans for a new frame. Getting the original frame useable is the goal right now. I do have a spare motor and could pick up another without much trouble and I might end up with the lightly modified stock bike to loan out to friends and a "trick" one for me to ride. At least until I get my XTY400 built. But there is no assurance I'll like that once I've built it. I have to admit that I was sorely tempted by a 1976 325 Alpina basket case that I saw on the local Craig's list yesterday. But it was soooo incomplete that even at $200 I was able to resist buying it just for the motor. A 325 Bul would probably be much more to my preference than my KT, but I know that I'm not outriding the KT. Buying yet another bike (when I'm trying to at least hold the line if not cut back) is something I don't need to do. cheers, Michael

The exhaust bandage is much more expedient. You might also look at tweaking the exhaust routing to move it farther away from the carb. I think many air-cooled trials bikes probably are overcooled, as they run for 3-5 minutes and then are shut off for 10-15. But you can certainly get into a "heat soak" situation if you get out of that mode, especially in hot weather. Coating the exhaust port will help to reduce the amount of heat that stays in the top end. Coating the piston crown and combustion chamber will also help. What might be a good move on a TL125 would be to see if you can fit the oilpump from a 185/200. We tried to get a small roadrace Formula class going that was based on the CB/CL/SL100/125 engine and I think that with the engine I started on I did fit a 185 oil pump. Circulating more oil can help to get the heat spread around where it can be radiated away. But the little Hondas do seem to want to run hot. My 175 based roadracer would get the cases much too hot to want to touch. A synthetic oil that would take more heat might be a good plan for a TL. You can always weld on fin extensions. A friend has done that to quite a few XL/XR350/500 Honda singles. cheers, Michael

I'm definitely aware of that. I need to check with a friend who is in the machining/fabrication trade and find out who he has do heat treating. I think a lot of the welding can be done in a way that qualifies as substantial overkill so that HT isn't needed, but if a lot of welding/bending needs to take place it may be easiest to start with something in "O" condition and send it out for HT. cheers, Michael

Things were just too sloppy at the swing arm pivot with the nominal (but slightly undersized and then slightly worn under the silentbloc bushings) 12mm pivot bolt, so I've reamed the center section of the frame out to a nice fit for 1/2". The outer support plates are still sloppy on that so they are going to come off and have new ones made and welded back on. I've got the new steel bushings blanked from some 7/8" Thomson linear shafting (just the regular case-hardened shafting, not the stuff that is also chromed though that would probably be better for longevity) and bored/reamed for the 1/2" shaft. They'll get faced to length after I decide what I'm doing with the rest of the parts and make the bronze bushings. cheers, Michael