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Discussion Starter #1
Just curious if I have any bolt-in options or if it's a hack and fab situation with my XS400 frame? I've been thinking about a single thumper 500 engine. I'm thinking from a XT as then it shouldn't have a starter on it and just the kick start option. Aftermarket is pretty big and the lump in my XS400 is a shot in the dark if it's good or not. I got a loose as it was froze when I got it and still needs carbs. I figure for the price I can get a 500 for a 38mm Mikuni round slide for it'd be fairly close to how much I'd spend on getting some carbs and then if it dud in the end. What the hell, if it doesn't fit. I've got my MIG, TIG, compressor and ample air cutting tools, so where there's power to plug my tools in, there's a way it's going in. Just curious as what experience people have had with these 500 singles? Only thing I've seen with the older singles is to run another oil line to the rocker cover on the exhaust side to aid with lubrication but then it was solved in later models.
 

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i bet you can get an xs400 engine on ebay less than a sr/xt motor. i have never had the oppurtunity to compare an sr frame to an xs frame. i have read that the 500 single engine is comprable in power to the xs. it would just have a lower redline and a different sound.

were you planning on putting vms on the xs400?
 

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Discussion Starter #3
I was planning on it. I just don't want to spend the two hundred or so for the carbs, throttle and cable and find out the stock lump is garbage. I may put up a WTB on craigslist and just watch ebay. Not to mention the 500 has a bigger aftermarket and one of each is cheaper and simplier also.
 

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You should be able to get the 500 single into the frame, but you may have to make some major mods to the frame to get it done. I think the engine might be too tall to fit under the backbone frame tubes unless it will fit down between the engine cradle frame tubes. Then you miht not be able to get the sidecovers off the engine without pulling the engine. None of the 2 valve Yamaha 500 singles had an electric starters so the SR/XT/TT should all work.

Ken
 

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Hey, Ken. Have you found a job yet? I have actually started classes (well, only one at the moment). Tonight is my second night this semester.
 

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Hey Judey,
I am still between schools at this point. However, my wife has found a very nice position that is paying her reasonably well. We just purchased a new home in the Twin Cities, so I have been by doing stuff with furniture, appliances and window treatments. I am holding out for a good position until we run out of money.

Ken
 

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Here's mine.
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This is a mock up pic from a while back. It's almost done. I'm with Ken on this one. The 500 is significantly bigger and will likely require a fresh sawzall blade to make it fit. I've got 2 xt500 frames in my shop. 1 is a roller, 1 is stripped out. got a couple motors too, but FR dibbsed them and around 3:27 am while we were while we were driving back from indy. Let me know if you want a frame.

unless you're going bore the thing the limit, stroke the crank, and run it WFO all the time the 38 will drown the plug. for the street, get the 34.

cheers, bcr
 

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dang it, your bike is going to be prettier than mine! and with good brakes!! hahahaha, thanks again for stopping in this weekend and picking up a shirt, i really appreciate it!
 

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from the carrier, it looks stock yamaha, just drilled out...however, the caliper is a modern two piston set up...BCR..divulge all your details, i need better brakes on my scooter!!
 

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howdy fellas,
the front hub is a drilled out rd 350 unit. I spun a spacer and mounted the drilled disk off my old dirt tracker which happened to be from the original sr500 donor bike. The front end consists of 38mm tubes, sliders, and triples off a fz600. I got the dual pot brembo off a ducati and milled a mount to line it all up. 2 fingers is all you need.
cheers, bcr
 

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Discussion Starter #12
BCR, you don't feel like easing up on your collection and hooking me up with a engine would you? I put on a WTB on CL but I didn't even get spam or spoof emails from it. Now that's an all time low on no response from a CL ad. lol. It's a bit of a longer term project as I picked up a beach cruiser that I'm gonna be messing with also. I just want to have my XS going by next summer.
 

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Slightly away from the Yam/XS discussion but a friend of mine had a bunch of parts laying around and decided to tick a Rotax 600 into a CB350 frame. He sent me a photo of the initial offering. Doesn't look too bad and I'm sure the finished product will be way ahead of the original motor.


By weslake, shot with <KENOX S630 / Samsung S630> at 2008-09-25
 

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stock 600 slowtax's are dogs, about 38hp...but that might be right with the original motor...not sure. however...you can get a taxi to about 70hp with a good head and some compression. a 665 motor will net you about 72 and a 676 (special road racing parts) will get you damn near 75hp. there is LOTS of potential in those motors if you talk to the right people
 

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Frank knows the right people. Thats a spare Paris-Dakar motor put together by a right person.
 
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