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CRF450R / CR500 Supermoto Project

Discussion in '2 smokers' started by J Banning, Dec 17, 2013.

  1. dhallilama

    dhallilama Long timer

    Joined:
    Apr 3, 2012
    Oddometer:
    1,409
    Location:
    Portland, OR, USA
    i love and hate threads like this...

    awesome build and looks like it'd be a blast! love that.

    i've a garage full of project and finished bikes, but come to think of it i don't have an open class 2 stroke in a modern chassis among them. hate that. :D
    #21
  2. Krasniewski

    Krasniewski I don't ride much.

    Joined:
    Feb 5, 2008
    Oddometer:
    1,267
    Location:
    LA - Lower Alabama
    This is awesome - I was just itching for a CR500 build.

    Are you bumping up the stator coil to run lights and the like, or is this a track-only build?

    Great work so far! Keep it goin. :norton
    #22
  3. Foot dragger

    Foot dragger singletracker

    Joined:
    Dec 27, 2006
    Oddometer:
    25,475
    Location:
    chico,just below rag dump(nor-cal)
    You were saying you wanted a 120mph super-moto bike,is it easier to make a CR500 go 120 as opposed to a pumped CRF450F? 450 revs higher as is? I know the go cart guys used to run big HP CR500's but they were usually a real short hour engine.
    Simpler to work on 2 strokes though for sure.
    #23
  4. J Banning

    J Banning Been here awhile

    Joined:
    Oct 9, 2007
    Oddometer:
    160
    Location:
    Newark, DE
    Wow, here’s my long overdue update. Sorry about that!

    The bike is now running and I’ve got about 700 miles on it. Here’s what happened from January till now…

    The engine:
    I did a conservative port job on the cylinder based on some recommendations I got from guys who road race and ice race their CR500s (190 exhaust duration and 125 on the transfer ports).

    My trusty porting tools -- the blue ¼” collet Makita for pretty much everything and the ⅛” collet Dremel with 90 degree adapter for the transfer ports.
    [​IMG]

    I enlarged and raised the boost ports in the intake
    [​IMG]

    For the exhaust port I smoothed, polished and matched it to the flange.
    [​IMG]

    I raised the transfer ports 1.2 mm and the exhaust port was raised 3mm and widened 3mm on each side.
    [​IMG]

    I opened up the transfers where they meet the case and knife edged them some.
    [​IMG]

    I then used a ball hone, some motor oil and a cordless drill to hone the cylinder. It’s times like these that being a bachelor is a good thing :)
    [​IMG]

    Some new parts I ordered for the bike finally arrived just in time for the engine assembly -- Boyesen engine covers, a Pro Design Cool Head, Keihin PWK 41 mm carburetor, and a set of sprockets from Sprocket Specialists (15 & 16 tooth front and a custom ordered 38 rear).
    [​IMG]
    [​IMG]

    I then cleared my kitchen table, grabbed my service manual and a couple beers and went to work assembling it all.
    [​IMG]

    That’s all for now.
    Coming in the next update… airbox modifications and the engine install.

    -B
    #24
  5. J Banning

    J Banning Been here awhile

    Joined:
    Oct 9, 2007
    Oddometer:
    160
    Location:
    Newark, DE
    Next steps: installing the engine, the air box and radiators

    Installing the engine
    Not much to say here. It went in fairly easy. Here’s some photos of the head stay and coil mount.
    [​IMG]
    [​IMG]

    I did have to bend the stock rear brake pedal to fit around the engine case. That was easy. I just marked lines for each bend and went slowly, one at a time until I had the clearance I wanted.
    [​IMG]

    Modifying the air box
    I used an air boot and filter flange from a 1999 CR250.
    [​IMG]

    I then had to cut the inside of the CRF450 air box to clear the flange and then drill and bolt the adapter plate to the box and flange.
    [​IMG]

    This took much longer than I expected. I’d estimate a good 3 hours to measure everything a couple times before cutting.
    [​IMG]

    Once I knew I had it right and did a test fit I then took it apart and used black RTV sealant between the plate and box.

    Radiators
    I had to modify both the lower fittings on each CRF450 radiator. The one on the left had to be cut and rotated up and the one on the right had to be cut off completely, the hole opened up and a new fitting welded on at a downward angle. I then drilled a hole in it and welded on a spare fitting I had for the crossover hose to the other radiator.
    [​IMG]

    Here you can see the angled fittings for the crossover hose
    [​IMG]

    Here you can see the angled fitting pointing to the water pump.
    [​IMG]

    At first I used a straight piece of hose but as you can see it had a slight kink in it. Once I got the bike running and warmed up it got far worse, but I was able to go to the auto parts store and get a formed hose that had a slight bend at the end. It worked perfect.

    -B
    #25
  6. J Banning

    J Banning Been here awhile

    Joined:
    Oct 9, 2007
    Oddometer:
    160
    Location:
    Newark, DE
    More fab work and then a running bike!

    OK, so now we’re into the March timeframe. I have the engine together and in the chassis. The air box mods are done and it’s mounted too. Now I only have to heat up and shape the bottom of the gas tank to clear the spark plug and then hook up the carb and exhaust.

    Forming the gas tank
    I used my heat gun to heat up the bottom of the tank (empty and dry first). I kept it at the distance seen in the picture and used slow circle motions to evenly heat the area I wanted to deform. Then, with a heavy leather work glove on I pushed it in and held it there for a minute or two while it cooled.

    [​IMG]

    Carb and exhaust
    Although I had a new carb (PWK 41mm) I still hadn’t gotten the exhaust system I wanted to go with it (CPI race pipe) so to get the bike running I put the Pro Circuit pipe, silencer and stock honda Keihin carb on.

    [​IMG]

    To save time and reduce headaches I left the gas tank off and instead hooked up my Motion Pro fuel can to the carb and rolled the motorcycle lift outside to attempt the bike’s first startup.

    Video: https://www.youtube.com/watch?v=8Tl1On3bBXM

    And with that I now have a complete, running CR500 supermoto!!!
    This is what it looked like
    [​IMG]
    #26
  7. dlrides

    dlrides 1:1.618 Supporter

    Joined:
    Jul 21, 2005
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    Location:
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    Great work !

    :clap
    #27
  8. J Banning

    J Banning Been here awhile

    Joined:
    Oct 9, 2007
    Oddometer:
    160
    Location:
    Newark, DE
    First ride and new exhaust

    I started the bike up and let it get up to temp and then cool down. I then did a gentle ride around my neighborhood on it then let it cool. I then went out and went through each gear, not beating on it, but letting it get on the pipe. The bike ran great. It had awesome power, even with the stock carb. T

    A few issues I noticed:
    1) The Pro Circuit pipe touched the water pump hoses. I had to wrap them in heat tape.
    2) The 15/38 gearing is really tall though. Makes it a pain in the ass to leave stops and intersections. Once you’re going though it’s no problem. The bike will cruise at 70 with ease.

    New exhaust
    My CPI race pipe finally showed up. I wanted the chrome plated version but for some reason they charged me for the bare steel version and that’s what I got. Whatever, I think it looks awesome. The custom Dyno Port silencer didn’t show up though so I ordered an off the shelf FMF silencer instead.

    [​IMG]

    Unfortunately, the CPI pipe needed a little work. One of the welds on the stinger section of the pipe was only half way completed and the exhaust flange up front was too tight so I had to take a 80 grit cartridge roll on my die grinder and open it up some. Once that was done it went on the bike. I was happy to see that there was more clearance between the pipe and the water pump hoses now.

    [​IMG]

    The FMF silencer needed some work too. In order to get it to align with the mounts I had on the subframe I had to cut and weld it. I suppose the Pro Circuit silencer I was running (off the old Service Honda bike) was custom made by Service Honda or there was a slight difference between the CR250 supframe on that bike and my CRF450 subframe. Regardless, I got it fixed. One at a time I made small cuts with a cutoff wheel until I got the bend I wanted. I then welded it up.

    [​IMG]

    Once that was completed I was done. I was also glad to see that there wasn't any clearance issues out back for the 160 rear tire. I can compress the suspension and the pipe won’t hit the silencer.

    [​IMG]

    -B
    #28
  9. J Banning

    J Banning Been here awhile

    Joined:
    Oct 9, 2007
    Oddometer:
    160
    Location:
    Newark, DE
    First time at the race track
    ...and it didn’t go so well.

    I was hoping to run the bike at Summit Point Shenandoah the following weekend but was nervous because I had the new pipe and carb on the bike now but no way without breaking a lot of laws to test it on the street to see if the tune was good. What I did then was load the bike up and head to New Jersey Motorsports Park and do a couple slow laps during their lunch break on the big track (Thunderbolt).

    [​IMG]

    The bike sounded different with the new pipe and silencer it was making awesome power. Perhaps too awesome… or perhaps awesomely lean is more like it. I burned a hole right through the top of the piston as I was coming onto the front straight at about 90 mph!!!!

    [​IMG]

    It didn’t seize, it just lost all compression. A post mortem revealed that although the pilot (50) and main jet (192) were fine, the needle (DGH) was way too lean.

    I got the bike home and that night had the engine out and tore down (only took an hour to have the cylinder and piston in my hands).

    I cleaned everything up and had a fresh piston in the bike and it was running again in 3 days. I took the bike out for a quick road test and everything appeared to be good to go.

    Road test video: https://www.youtube.com/watch?v=rzun0c_uotA

    I was now ready for the big weekend at Summit Point

    Summit Point trackday
    Based on the meltdown at NJMP I changed needles and went with a DEG (different length and diameter). The bike stayed together the entire day and I had a great time. I think I did six twenty minute long sessions on the bike.

    Here’s a short video from early in the day:
    https://www.youtube.com/watch?v=-M_X575CKm4

    Need to do a little tweaking to the jetting. Too rich at lower speeds and I think the 192 main is too rich as well, hurting top end power… but it was still fast enough to run dead even with 70hp Aprilia 550SXVs!

    -B
    #29
  10. J Banning

    J Banning Been here awhile

    Joined:
    Oct 9, 2007
    Oddometer:
    160
    Location:
    Newark, DE
    Updates from the Tail of the Dragon

    Towards the end of May I spent a week in Western North Carolina and got to ride the CR500 on the Tail of the Dragon.

    Here's some Killboy.com photos
    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]

    And some video:

    <iframe width="560" height="315" src="//www.youtube.com/embed/thEqiIqZeYY" frameborder="0" allowfullscreen></iframe>

    <iframe width="560" height="315" src="//www.youtube.com/embed/SqHnuF7-FNY" frameborder="0" allowfullscreen></iframe>

    -B
    #30
  11. bobfab

    bobfab Long timer Supporter

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    Limerick, PA
    :clap:clap:clap awesome!
    #31
  12. J Banning

    J Banning Been here awhile

    Joined:
    Oct 9, 2007
    Oddometer:
    160
    Location:
    Newark, DE
    Thank you
    #32
  13. pdxjim

    pdxjim Two Stroke Terror

    Joined:
    Sep 14, 2009
    Oddometer:
    275
    Location:
    Portland, OR
    Rad,

    I've been having a blast on my street titled supermoto 300exc.

    Those extra 200cc's must be a hoot.
    #33
  14. Fast1

    Fast1 Twisted Throttle

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    Aug 18, 2007
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    Location:
    Bridge over Troubled Water
    dream bike!

    What kinda of range do you get with the 500 during street us?
    #34
  15. J Banning

    J Banning Been here awhile

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    Oct 9, 2007
    Oddometer:
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    Newark, DE
    That depends on how it's being ridden, but it's not good either way.
    30 mpg if I'm riding the speed limit and no hooning. 25 mpg or less if I'm getting on it.

    The stock tank is small to begin with -- 1.9 gallons -- plus it has no reserve, and I probably lost an 1/8th of a gallon of capacity pushing the bottom of the tank in to clear the spark plug and coolant lines. With all that being said I'd say that there's really only 1.25 gallons of usable fuel in the tank. If I'm street riding I carry oil with me (in a translucent Stabil container with markings) and I aim to stop for fuel every 30 miles. If I'm at the track I top off after every session.

    Companies like IMS or Clarke make larger tanks, but that larger capacity comes in the sides and bottom of the tank. I assume that I'd have to do a LOT of reforming of the tank to *possibly* make it work. I have no plans to do that.
    #35
  16. BikePilot

    BikePilot Long timer

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    Location:
    Golden CO
    Nice project! CR5s broke pistons a lot in stock form. All three of the ones in my family years ago broke or cracked pistons. For light dirt work a forged wiseco fixed it. I think the root cause was Honda's poor head design--you may have fixed that with the cool head. Awesome to see the bike running!
    #36
  17. jar944

    jar944 Long timer

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    Warrenton
    I have a cracked wiseco here that proves otherwise.

    Running the piston too long or with too much clearance kills the pistons. The head design isn't that bad.
    #37
  18. Norty01

    Norty01 Occupant

    Joined:
    Jan 30, 2014
    Oddometer:
    2,757
    Location:
    CARLSBAD, CA, USA
    Impressive work. Cutting and rewelding a frame takes skill and courage. You appear to have both.
    Just how "streetable" is a modded CR 500 engine?:wink:

    Lastly, what's it's wet weight?
    #38
  19. J Banning

    J Banning Been here awhile

    Joined:
    Oct 9, 2007
    Oddometer:
    160
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    Newark, DE
    Thanks for the compliments.

    Regarding how streetable it is, I guess everyone has a different idea what that means. What I can tell you is that it will easily cruise at 70 mph without a problem. At WOT it'll do between 115-117 mph. However, the thin MX seat and no wind protection make extended periods on the bike tough... plus the small stock gas tank (about 1.6 gal) and having to mix fuel make fuel stops a pain in the ass. There's no reserve and if I'm hauling ass with the bike I'll only get about 25 mpg, meaning I'll want to be dam close to a gas station when the odometer hits 30. Because I ride it hard I mix my fuel/oil at 32:1, so for a full day on the bike I gotta bring a lot of oil in my backpack. I've found that a 64oz Gatorade bottle helps too, so I can always top off the gas tank. Carrying all that stuff sucks though. A different carb (Smartcarb or Pulse Injected Air Striker) could help the fuel mileage, as could a larger tank, but the larger tank usually comes at the expense of less space around the top of the motor... so I'm sure that would mean a lot of heating and reshaping to make it fit, *if* it'll fit.

    With all that being said, this bike isn't as streetable as I had hoped for. It's kinda like meeting up with all your Mustang driving buddies for a Sunday drive and you're driving a track prepped Corvette with a small fuel cell. It's loud, not very comfortable, and gets shitty gas mileage... but damn, is it a rush to drive!

    With that being said, I'll be keeping this bike for track days and short hooligan rides, but I'm looking for a used DR-Z400SM as a cheap & reliable "daily supermoto" (i.e.: my Mustang) for gravel roads and and longer day rides.
    #39
  20. Fast1

    Fast1 Twisted Throttle

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    Location:
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    Just toss it on a trailer and head for a week of riding in the dunes of Glamis and you will realize that it is "king" of all bikes (which you most likely know) in that environment.

    I believe there is an oversized tank available but it does impede access to the plug and most likely will require some heat/shaping to fit according to Service Honda.
    #40