• Hi everyone,

    As you all know, Coffee (Dean) passed away a couple of years ago. I am Dean's ex-wife's husband and happen to have spent my career in tech. Over the years, I occasionally helped Dean with various tech issues.

    When he passed, I worked with his kids to gather the necessary credentials to keep this site running. Since then (and for however long they worked with Coffee), Woodschick and Dirtdame have been maintaining the site and covering the costs. Without their hard work and financial support, CafeHusky would have been lost.

    Over the past couple of weeks, I’ve been working to migrate the site to a free cloud compute instance so that Woodschick and Dirtdame no longer have to fund it. At the same time, I’ve updated the site to a current version of XenForo (the discussion software it runs on). The previous version was outdated and no longer supported.

    Unfortunately, the new software version doesn’t support importing the old site’s styles, so for now, you’ll see the XenForo default style. This may change over time.

    Coffee didn’t document the work he did on the site, so I’ve been digging through the old setup to understand how everything was running. There may still be things I’ve missed. One known issue is that email functionality is not yet working on the new site, but I hope to resolve this over time.

    Thanks for your patience and support!

So what do you think of my project?

Wallybean I have a mx racing buddy that is trying to talk me into a trip down to Moab in Feb-March. Which bike would work better my tc250 or cr144. My Buddy went last year and loved it but he is a better rider than me and hope I am not getting over my head if I go with him.
 
You can't go wrong with either one. I have used 144, WR250, WR360 and they all work great. The WR250 was probably my favorite of those three because it did everything well and still handled the sandy/silty areas well like whitewash.
 
just drop it off at eriks, the guy with the WR250 with the vintage collection. He buys up about every DG pipe on ebay and makes em fit on everything, tellin ya, he would have a sweet pipe on that thing in about 45 minutes.
 
montgob1 said:
just drop it off at eriks, the guy with the WR250 with the vintage collection. He buys up about every DG pipe on ebay and makes em fit on everything, tellin ya, he would have a sweet pipe on that thing in about 45 minutes.
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Who is this?
 
RB Designs is Ron Black. He does some novel head squish band mods for two strokes, as well as PWK mods for better low end power. I had him do those exact things for the KDX motor in my KX-DX hybrid, and it runs superb.

Kelly, this sounds like an awesome build. The biggest problems with motor swaps in general, in order of difficulty to overcome, is pipe-frame clearance, pipe fabrication, and swing arm to case mating. With regards to the pipe and frame clearance, you have to raise the point where the cradle splits off from the frame below the steering stem. I think the easiest way is to get a YZ 465 frame, cut the cradle tubes out, and graft them onto the RMZ frame after lopping enough of the frame off to clear the 465's exhaust port. This method is elegant, in that your lower engine mounts are done for you already.

To do that, you must first get the swing arm and cases talking to each other. I bet the YZ swing arm pivot is narrower than the RMZ's, so you'll have to get the bushings in the YZ's cases reamed out to the proper diameter. You may also need to fiddle with the width of the swing arm bearings, which might require having the inner races of those bearings ground to the right length. Once you have the RMZ swing arm pivot bolt through the YZ cases and the swing arm accommodating the YZ motor, slap it in the frame, verify sprocket alignment, and then plAy with the angle of the motor to optimize the countershaft sprocket to swing arm pivot relationship, as well as carb-to-intake alignment. You may do well to have a YZ 490 intake boot handy to mount up to the RMZ air box.

Ooo, these projects are fun!

I also might suggest picking up a late-model CR 500 pipe to modify to fit the RMZ chassis. Of all the big bore pipes available, it will probably require the fewest cuts to fit in the RMZ frame.
 
dfeckel said:
Kelly, this sounds like an awesome build. The biggest problems with motor swaps in general, in order of difficulty to overcome, is pipe-frame clearance, pipe fabrication, and swing arm to case mating. With regards to the pipe and frame clearance, you have to raise the point where the cradle splits off from the frame below the steering stem. I think the easiest way is to get a YZ 465 frame, cut the cradle tubes out, and graft them onto the RMZ frame after lopping enough of the frame off to clear the 465's exhaust port. This method is elegant, in that your lower engine mounts are done for you already.
Click to expand...

I chose the RMZ frame because it is steel and single down tube all the way to the bottom. YZ465 is side exhaust and the 490 is center. I don't think it is a huge deal. As for the swing arm I know machinist and fabricators that can do anything. I bet that is not far off. A few spacers and maybe some machining here and there. I measured up the huge Rotax 406 motor and it would fit so I hope the YZ does without to much of a fight. Starting to get stoked.
 
Yes, hard to put those first bikes out of your mind. If I were you.... Your TC250 and 400WR would be "The Frankenbike"!
 
Norman Foley said:
Yes, hard to put those first bikes out of your mind. If I were you.... Your TC250 and 400WR would be "The Frankenbike"!
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I wanted air cooled simplicity. But the WR400 motor is nice.

RMZ...

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Extra set of bling. I think I have a 19" paddle tire around here somewhere too.

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Good luck I think the project is a fabulous idea. Please keep the photos coming.
I always thought my old 96 Yammy TT350 motor (air/oil cooled) with 6 speed box was a cracker in the bush. It would be brilliant with a modern frame and suspension. Might have to copy you.
Good luck.
 
ghte said:
Good luck I think the project is a fabulous idea. Please keep the photos coming.
I always thought my old 96 Yammy TT350 motor (air/oil cooled) with 6 speed box was a cracker in the bush. It would be brilliant with a modern frame and suspension. Might have to copy you.
Good luck.
Click to expand...

Thanks, I have been kicking around this idea for many years and I finally put the feelers out for a rolling chassis and found out a good buddy had exactly what I needed sitting in his garage collecting dust. When he sold it to me for next to nothing it was on. No excuses now. It is happening. Think I already have the hard parts sorted, not going to be super hard.
 
Slowpoke said:
I think your biggest issue will be getting more than 20-30 mins out of that little RMZ tank........ :D
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there is a 2.3 gallong tank for the bike and I am going to have an aluminum fuel cell built to go where the rads were. So there :cool: So with all that I should be good for 45-55 minutes he he he Might not be able to ride the beast for longer than that. Might need to look into a case of rear fenders. I remember my YZ465 wanting to loop a lot, this should be worse.
 
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