Paul1212

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About Paul1212

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  1. Thanks to everyone who responded to my questions. I'm going to need to do some study and checking on some issues, like what kind of head gasket my mechanic put in, and whether using a thicker base gasket might help.
  2. Thanks for all the replies so far. To 150ron - before the cylinder replacement, I would see temperatures up to 275 F., and on one 90 mile trip where I was pushing the bike hard (between 105-112 kph [65-70 mph]), it went up to 285. I've communicated with a Castrol rep by email, who recommended that I switch from the semi-synthetic oil I was using to a full synthetic, which I've done now. (He said the semi-synthetic was good for temps up to 265.) After switching to the full synthetic oil, temperatures seem to be lower (265-270 max), but I haven't pushed the bike hard yet since the oil change. To keenxxx and kfngrn - I'm confused about the reason for the increased compression (which seems to be the case, since the bike has more power). From what I understand, the top of the cylinder rim sits a little bit above the top of the cylinder head; I assume that's because the gasket covers the head but not the center part of the head where the cylinder is. I think my mechanic had the head milled down, but not the top of the cylinder rim - in other words, the part of the head around the rim of the cylinder. Since combustion takes place inside the cylinder, it seems to me that milling down the head around the cylinder wouldn't increase compression, but rather it's probably because the new cylinder is probably a little lower (shorter) than the original; a slightly shorter cylinder would thus increase compression. I'll check with my mechanic about my understanding of this. As I said, I'm not highly knowledgable about motorcycle engines, so I may have some of this wrong. To Baja trail Rider - I think my mechanic just cut a thicker piece of cork to adjust for the increased gap due to the head being milled down (he said it was milled just a very small amount). But I'm not sure about that. One person here told me that the Baja uses a metal head gasket, but I haven't checked on that, yet.
  3. About 10 months ago, my 2003 xr250 Baja started leaking oil at the head gasket (not a lot, but more than just a film of oil on the fins). Since I was due for general engine maintenance inspection and timing chain replacement, I asked my Thai mechanic (I live in Thailand) to see if he could fix the oil leak as well. He adjusted the valves, and put in a new timing chain, piston rings, valve stem seals, cylinder head gasket, spark plug, and also a metal cylinder related to the piston (not sure what it was, but it measured about 3 inches long and 1 inch in diameter). This stopped the leak for a couple of months, but then it returned, and got progressively worse. My mechanic checked the engine again, and decided that the distance between the top of the cylinder and the top of the cylinder head was too small - in other words, that the top of the cylinder had worn down. So he had a local lathe shop grind down the top of the cylinder head a little bit. There is a spec mentioned in the manual (I have both the Baja manual in Japanese and a manual for the xr250r in English) that refers to the maximum allowance for warpage on the top of the cylinder head (0.10 mm), but my mechanic took this to refer to the maximum distance between the top of the cylinder and the top of the cylinder head. When I explained to him that that spec was for warpage, he said that Thai mechanics he had talked with took that spec to refer to the maximum distance between the top of the cylinder and the top of the cylinder head! I’m not very knowledgeable about motorcycle engines, and didn’t realize his mistake until after the repair was made. This fix stopped the oil leak at the head gasket for a few weeks, and then it returned. So next, he had the local lathe shop make a new cylinder for the engine, so that the top of the cylinder would be a greater distance above the top of the cylinder head. He said that the only other alternative would be to buy an entire new Japanese-made engine for about $1500, so I let him make that repair. (It only cost $50 for the new cylinder, and another $20 for 2 gaskets; labor in Thailand is very inexpensive.) I wasn’t sure that this was the right way to go, but as the engine was leaking quite a bit of oil at the head gasket, and as the Baja is my only means of transportation, I wasn't able to wait to research the problem. Now, the surprising thing is that, after almost 2 months (and an initial 1000 km break-in period where I tried not to drive the bike hard), not only is there no more oil leaking at the head gasket, but the engine has more power than before. (It also seems to work a little harder - judging by the sound of the engine at higher revs - and run a little hotter than before as well, but as I’ve recently switched to a full-synthetic oil, I’m not too concerned about the extra heat.) So my questions, for those with experience in this area, are: 1. (main question) Is my Thai mechanic correct in his belief that 0.10 mm is the correct maximum distance between the top of the cylinder and the top of the cylinder head? Does anyone know the correct distance for this spec? 2. I’m concerned about problems developing if the new cylinder wasn’t made to exact specifications. What problems would I notice if the cylinder isn’t exactly the correct size, or if the kind of metal used isn’t of the same high quality as the original? 3. Since my bike doesn’t have a tachometer, how can I tell if I’m running the engine too hard? (especially re. higher speeds in 6th gear; in the past, at speeds over 110 kph, the engine would sound like it was working hard; now it sounds like the engine’s working hard at speeds over 105 - not a huge difference.) Can I judge this by the engine temperature? (I have an Xrs Only temperature gauge that is used in place of the oil dipstick.) Thanks for any help anyone can give with my questions. Qualified xr mechanics are very hard to find here in Thailand.
  4. n16ht5 - here's one post regarding importing bikes to the U.S. - http://www.thumpertalk.com/forum/showthread.php?t=607843&highlight=importing other than that, I'd suggest you do a search for "MD30" (the first VIN numbers on the Japanese version xr250) here at thumpertalk and check out the threads. I did the search and got 13 hits, but didn't read them.
  5. Thanks to everyone for all the replies. I've done some more reading on this the past week, and have corresponded with Baja Designs and Trail Tech. Hondapro, from what I now understand, you are correct in saying that the stator must put out enough watts to cover all the lights and electrical output of the bike and keep the battery charged. Going by what they wrote, and by michigan400's comments, it looks like my 204 watt system might give me 150-170 watts for lighting at high rpm's. I think I'll see what I can do with that, running two 35 watt headlights and either 90 or 110 watts of driving lights, and see if I can get by without rewinding the stator for now (especially since I've only found one mechanic here in northern Thailand who knows how to rewind a stator, and I'm not sure how proficient he is). I think I'll put the two driving lights on separate switches and buy a inline voltmeter so I can monitor my available voltage and only use the driving lights when the battery is being charged well. To n16ht5 & Chiefculprit - do you know of any reasonably-priced HID conversion kits? I've checked a number of motorcycle websites (mot-superst, rockymt.atv, revzilla, jcwhitney...), and the cheapest HID conversion I found was for $200 (XenonDepot).
  6. Thanks for this information, michigan. Very helpful. The bike does have a battery.
  7. n16ht5, it looks like you live in Washington, so I assume you mean importing them from Japan to the U.S., right? I'm afraid I don't know anything about that. Here in Thailand, used bikes are imported from Japan to sell. This link gives some more information about these two bikes (pic only of the xr250, but specs for the regular xr250 and the xr250 Baja) - http://world.honda.com/news/2003/2030227.html The horsepower (Maximum Power) rating is 28; I think the 21 is some metric or Japanese-specific unit of power. The next link shows a picture of the 2003 Baja bike (text is in Japanese) http://www.honda.co.jp/factbook/motor/xr250xrbaja/200302/001.html
  8. I live in Thailand and just bought a 2003 xr250 Baja bike. It's the Japanese MD30 model (first digits of the frame number), which is different from the xr250's sold in the U.S. For example, the generator output is 204 watts at 5000 rpm's. (I think that spec for the exported-to-the-U.S. xr250's is just 140 watts). It's also a heavier bike (130 kg dry weight; 128 kg for the non-Baja MD30 xr250), and the stock sprockets are 13 front and 39 rear. I have a copy of the service manual in Japanese, and can figure out some of the stuff by comparing it with a copy of the exported xr250 which I downloaded, since the two manuals are set up similarly, and by looking at the pictures. When I see a spec that I have an idea what it might mean, I type the English term into translate.google.com, and see if the Japanese translation is what's in the manual. If anyone has one of these kinds of xr250 bikes and would like me to check the manual for information, you can pm or email me. - Paul
  9. I have a couple of questions related to my bike's electrical output and whether it's necessary to rewind the stator on my bike to be able to handle a brighter light. I recently bought a 2003 xr250 Baja (Asian MD30 model), which has an generator output spec of 204 watts at 5,000 rpm's. From having previously looked into the possibility of getting a Baja Designs or Trail Tech aftermarket headlight, my understanding was that in order for my bike to be able to handle more than 100 watts of lighting, I would need to get the stator rewound. My current stock dual headlight uses 70 watts, but I hope to upgrade that to 100 watts and then add one or two Hella driving lights, each of which uses a 55 watt bulb. I found a mechanic here in Thailand where I live, who has rewound stators before. He told me that he would recommend running the driving lights directly off of the battery with a relay, in which case it would not be necessary to rewind the stator, since the power for the lights would come from the battery and not the engine's electrical system. Is this right? My second question is, how many watts of lighting can my electrical system handle? The service manual says that the generator output is 204 watts at 5000 rpm's. I've read some comments that this means it could handle a full 200 watts of lighting, and other comments that it could handle half of the generator output, about 100 watts. Which is correct? Thanks for any help anyone can give with these questions. - Paul
  10. I live in Thailand, and am looking at xr250's to buy one. The models sold here are the MD-30's, made in Japan. I have the same question about the year of production. This past Sunday a guy told me the code works like this: the three digits after the MD30 indicate the year, as follows: 140=2000, 150=2001, 160=2002, 170=2003, etc. The year of production should also be stamped on the black cable hose that loops over the speedometer (the brake cable I think) and on the wheels (if they are original). I've also been told that the year of production is stamped on the inside of some of the plastic side panels, but haven't checked on this yet. Anyway, the code I've mentioned seems to fit with the year indicated on the wheels and brake cable on the bikes I've looked at, but I haven't yet found a webpost that will confirm this (it doesn't help that I can't read Japanese).
  11. Thanks for the suggestion, Steve. I ride 95% street, 5% dirt. In six years of riding here in Thailand, I've gone down hard 3 times - twice on pavement (once due to braking on dirt tires just after it had rained, the second time a dog ran into my rear wheel and upended me), and once on dirt. I'm actually more concerned about the light breaking if I were to go down on pavement again, since pavement is harder than dirt.
  12. Question about Aztec8 dual headlight & customer service ________________________________________ I'm looking for a bright aftermarket headlight to replace a stock xr250r headlight, since I do a fair amount of night driving. I want one with low & high beam, so that rules out the Baja Designs 8" Race Light, the Trail Tech 8" Race Light, and the Ricky Stator Dual PIAA Universal Light Kit! From what I've found on the internet so far, what looks best is the Aztec8 dual 5 3/4" light - http://www.aztec8.com/catalog/i40.html Some sample pics on these pages - http://www.aztec8.com/id94.html http://www.aztec8.com/id77.html http://www.aztec8.com/id105.html but I have a couple of questions about it: (1) One thing that concerns me is that it doesn't have a protective frame around the light like the Baja Designs and Trail Tech lights do (the Trail Tech frame looks nice and heavy). Do you think the Aztec8 light (which is glass, not plastic) would be likely to break from a fall? (2) Has anyone had any experience with Aztec8's customer service? I sent one email that got answered right away, and then my 2nd email (sent 2 weeks ago) never got answered, even after I re-sent it after one week. One of my questions in the 2nd email was about a comment I read at a thumpertalk post that said that the light was not waterproof, and I asked about that. Could that have ticked them off? Or if anyone knows of a good bright aftermarket headlight that has a protective frame, please let me know. Thanks for any help...
  13. I've received a lot of help from posts here. I'd like to return the favor by posting a link to downloading free motorcycle service manuals (all Honda, I think). I was looking for a service manual free-download for an xr250r, and wasn't having any luck with different webposts I found through Google, and then I tried a link to a Thai website called www.cm-club.com, and their link - to another website called hondahookup.com - worked. I was able to successfully download the service manual for the xr250r, so I'm posting this link for anyone who needs a free Honda motorcycle service manual download: http://www.cm-club.com/vb/archive/index.php/t-64358.html (the motorcycle manuals are listed part way down this page under "Bike Manuals") The link in the above webpage is to this webpage: http://www.hondahookup.com/manuals/ You have to register (for free) at hondahookup, but it was easy and no hassle.
  14. Thanks to everyone for all the replies, esp. to Chemicalanarchy for the best thought-out response. I think the way I worded the topic makes it sound like I enjoy hitting dogs with my motorcycle, but that's not the case; the time I ran over the dog, I felt really bad about it. Another thought on the topic - I remember reading a post on this subject a while ago, and the rider said if you're going to have to hit a dog, it's better to accelerate before the collision, so that the front of the bike is lighter and will go over the dog easier, whereas braking puts more weight on the front wheel and makes it less likely to go over the dog. For myself, I don't think I'll try that, since when I see a dog in front of me on the road, I'm usually hitting the horn and braking at the same time, hoping he'll get out of my way in time. But the principle is good to know in cases where it's inevitable that you're going to go over a large object, like a dead body. Actually (another true Thailand story), I once almost did that. I was driving on a freeway late one night in northern Thailand, doing about 60 mph and riding behind a big tour bus. Suddenly the bus changed lanes, and I instinctively (or providentially?) changed with him, and just missed running over a dead body on the road. I know the guy was dead, because I stopped and went back to see if I could help (I've had some first aid training). I found the guy's motorcycle a little ways down the road on the median strip, with the front end totally compacted; looked like he was hit head-on. Riding a motorcycle in Thailand is never boring, and can make a praying man out of you.
  15. Woops - forgot to read page 2 before that last post. Make it 6 to 1 now in favor of the xr250r over the drz400sm for stability when colliding with an animal.