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gretschbang

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About gretschbang

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    California

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  1. gretschbang

    Pistons Aren't Round: Profile and Ovality Explained

    I tried the 90 degree rotation but couldn’t get the wrist pin to fit right, so I turned the rest of the engine 90 degrees too and it fit in perfectly; no problems with seizing.
  2. gretschbang

    Pistons Aren't Round: Profile and Ovality Explained

    Occasionally I see mechanical discussions on forums get hijacked by “dreamers”. Most of these dreamers fail to spend any time reading existing literature on designs that have already been conceived, designed, built and tested. They are unfamiliar with current restrictions and goals that the real designers inside the great engine houses (Honda, Mercedes, BMW, VW, Renault, Ferrari, Kawasaki, Yamaha, KTM, GE, Rolls-Royce, etc) face. Reality 1: the types of fuels and lubricants available are governed by economies of scale for mass production. Reality 2: the materials, tools and methods available for construction are also restricted to those that are suited for mass production Reality 3: serviceability on a consumer scale (if it needs service who can fix it and how can they get the parts) Reality 4: does a design change 1) reduce weight, 2) improve power per unit of energy source, 3) decrease cost 4) improve reliability I joke that the goal of performance design is smaller, faster, cheaper, bigger, and exactly the same, as moving the capability in one dimension negatively affecting others. Most exotic Engine designs are creative mechanical linkages that sacrifice some dimension of performance to compensate for a known deficiency. The most recent drive train improvements to reach consumer are the double clutch automatic-shift transmissions that enable 8,9,10 and more gear ratios to keep the engine in the optimal power-torque range, electric hybrid engines that allow for higher efficiency Atkinson cycle engines and all-electric drive. There is a common theme to these: none of which are bad seals or complicated linkages, or 90% reduction in reliability.
  3. gretschbang

    How to start an XR400

    I’ll check that. Thanks.
  4. gretschbang

    How to start an XR400

    @firstplacephoto well, technically it's 80% of an XR400, dry-weight is 257 pounds (according to the specs).
  5. gretschbang

    How to start an XR400

    @bajatrailrider I won't argue with your experience on the service side. I haven't had that problem, but that's not saying that I won't find out I've just destroyed my petcock seal next time I go out to ride. Thanks for sharing your expertise.
  6. gretschbang

    How to start an XR400

    If you found this, you are probably frustrated by difficulties in starting an XR400, I can tell you this, there is no "fool-proof" way of starting this beast of a machine, but, I have had 100% success starting my 2003 XR400 in one or two "hard" kicks for the past 10 years. I will add, for color, that prior to about 2008, I tried many different methods, but most of them were hit and miss at best leaving me frustrated and sitting next to what amounted to a 200 lb anchor. I know you want to get to the solution, and what I'm about to write may just cause greater frustration, but this is absolutely critical to successful, happy, ownership and enjoyment of this torque-monster. First: you have to have the correct jetting of the carburetor. The best way I have found to keep the jetting at the correct values is to call ahead to a Honda Powersports Repair shop in the area I'm going to ride and ask them what they install for XR400 owners in their area. Elevation above sea-level is the key variable here. Asking someone in San Diego what they recommend is useless if you are going to ride at 5000 ft MSL in the Sierras. If you are running too rich or too lean, you will have so many problems with starting, running, and servicing that you will absolutely hate the machine. Second (and Fourth): Successful starting of an XR400 is tightly tied to proper shut-down practices. Over time, I found that leaving gasoline in the float-bowl for even more than a few hours led to problems in starting. When shutting down for more than a few minutes, I suggest you don't just push the kill-switch. Instead, turn the fuel-petcock to "Off" and let the engine run the fuel out of the carburetor bowl until it sputters and dies. Third (the meat): 1. Turn the fuel flow on by turning the fuel-petcock to ON or RES (if you are low on fuel). 2. Put the choke on full (Full-Up) 3. Pull in the compression release lever while turning the engine over with the kick-start pedal SLOWLY, I use 20 (yes TWENTY) slow, comfortable, easy cranks with the compression pulled in. I don't have a good theory of why this is necessary, it has something to do with both the time it takes to fill the carburetor bowl AND with "charging up" the electrical system. Just waiting doesn't do it. Kicking quickly just gets you tired and doesn't seem to take enough time. 4. Release the compression release lever, and turn the engine over until it gets to the compression stroke and gives you that hard-resistance to your easy cranking. 5. You should not have turned the throttle at all, although "pumping it" a couple of times doesn't seem to help or hurt, but it should be all the way closed when you kick it. 6. Now KICK with all you got. I've expanded over the years to 280 lbs, so I just rise up and drop on it. You feather weights will have to lay into it. 7. Nine times out of ten, it just goes "woof" on the first kick. This is probably just poor mix in the chamber due to all of the cranking. 8. Now cycle it around to compression stroke again. Now KICK with all you got again. I usually get start on this kick. You may need to kick again, but if it didn't start on the third, think through what you did. Is the choke full on? did you really turn on the fuel? Check your procedure and try again. Once it fires up, nurse it a little bit until you can get to half choke, then full choke. Fourth. If you are through riding for the session and going to rest for a couple of hours (long enough for the engine to cool down), use the "fuel run-out" method for shutting down. I won't guarantee that this will start your XR400. You may have any number of other things going on, and a trip to the Honda service center may be in order, but following these rules gives me confidence that the engine will start without great effort where ever I may be. One thing is for sure, this is not a "quick-get away" machine. On the other hand, the low RPM torque on this bike has got my fat-butt out of trouble so many times I have lost track, sudden, soft sand, loose dirt on a steep hill, deep water, etc. every time I'm surprised, I keep my feet up and use the throttle and transmission to put me in the power band, and "oomph", I'm up and out of it. I hope this helps you with your XR400. After 15 years and thousands of hours in mountain and desert riding my XR400 I think it is still one of the greatest off road bikes ever made. AND my 2003 is a Green Sticker bike in California so I can ride it year round!
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