//ArrowChat Code
Page 1 of 5 1 2 3 ... LastLast
Results 1 to 15 of 67

Thread: Tecate engine swap & build thread

  1. #1
    Join Date
    Nov 2006
    Location
    southern oregon
    --
    2,338

    Tecate engine swap & build thread

    I am trying to decide what engine to use for my 1st Gen tecate project. My choices are: 1984 KXT250 W/KX cylinder, 1985 KX250, or a 1991 KDX 250 W/ '88KX cylinder...

    * If I use the '84 engine... I have to buy a piston, gaskets, swap the crank into good cases(i have them), get another T3 flywheel(or steal the '85 kx ignition again), buy another faded(ugly) tecate fuel tank, and live with a smashed up engine cradle...

    * If I use the '85 KX engine.... I have all the parts for the engine. I would have to build a new engine cradle to allow for the center exiting exhaust . I also have to fix a couple dents in the pro-circuit pipe and bend the stinger around a bit... With enough bending It may fit with the gas tank I wanna use...

    *If I use the '91 KDX250 engine... I still have to modify the trike frame, But I can rob the bikes original frame for the cradle. The FMF fatty pipe would fit very well, and allow ample clearance for the 1986 kdx200 gas tank that I really want to run. The '91 engine also has a better powervalve set-up, a wider ratio trans(which I think could be a good thing), a heavier flywheel(good on trails), and a headlight(good at night).. I hate to cut up a complete bike, but it needs more put into it than its worth to me as a running bike. Its ugly and way too heavy for a 250 IMO...

    I am leaning towards using the KDX as a donor and selling off the left-over bike parts. I think the '85 KX250 engine may end up in my quadracer at some point... The original tecate engine would be the easiest to use, but is kinda ordinary and a bit pipey for extreme trail use, and the frame is already less than perfect... I may keep the Tecate engine parts and pipes around for another tecate build-up using a nicer frame...

    Anybody care to share opinions? I am kinda hesitant to begin the frame mods, But I know I could pull it off with a few tack welds and the help of a local professional welder...
    Last edited by cr480r; 12-20-2010 at 12:53 AM.
    2-stroke lover

  2. #2
    Join Date
    Sep 2006
    Location
    Shreveport, Louisiana
    --
    888
    I like the KDX engine option for the reason you already stated. Go ahead and cutup the bike frame. Is it fairly straightforward to install the bike portion? Sounds like that's what you want, just do it, would be a nice trike when complete. How well does the KDX tank fit and look on the T3?
    >>>>>>>>>>>>>>>2007 Yamaha Raptor 700R>>>Cross Country Racer<<<<<<<<<<<<<<

    www.myspace.com/bluelionracing

    Support my 2009 sponsor:

    For all your ATV suspension needs.

  3. #3
    Join Date
    Nov 2006
    Location
    southern oregon
    --
    2,338
    Quote Originally Posted by ccdhowell
    How well does the KDX tank fit and look on the T3?
    Well I think it will look preety good. Its shorter and wider than the tecate tank. It should have enough clearance to allow a generous cut on the steering stops too. It wont work with the left-side tecate exhaust... As the low-side of the tank and the fuel petcock is on the left... My tank is a lil faded, but I began sanding a small spot and the color came right back.

    EDIT: The KDX tank needs a customized seat to look right... I didnt have a seat when I began building so I didnt realize...
    Last edited by cr480r; 11-21-2007 at 08:55 AM.
    2-stroke lover

  4. #4
    Join Date
    Nov 2006
    Location
    southern oregon
    --
    2,338
    Quote Originally Posted by ccdhowell
    Is it fairly straightforward to install the bike portion? Sounds like that's what you want, just do it, would be a nice trike when complete.
    They looked pretty close when I put the frames side by side... . I am just not sure what the strongest way to join them will be. Without too much trouble I think they will match up and look pretty good really. I am mostly worried about the durability... I ride fast, but I dont often jump very high on 3 wheels... so I think it should be fine if its done correctly... I would like to find some pictures of frames that have been modified to get an idea of the correct methods .
    2-stroke lover

  5. #5
    Join Date
    Nov 2003
    Location
    Newfoundland
    --
    5,281
    I vote KDX. WOuld be a nice trail machine with some power. Much more suited to woods then the 84 T3. I have an engine cradle you can have for cost of shipping. Its a KX500 cradle but it should work. I'll cut off the bottom mounts as one is broken and its been fixed using a washer.

  6. #6
    Join Date
    Nov 2003
    Location
    Newfoundland
    --
    5,281
    Joining frames is easy. Find a bolt that fits snug inside the frame tubing, cut the head off and tap it in the old frame so that the new section of frame can be slid over it. Leave about an eigth of space between the two frames so the bolt is exposed and weld the groove. Its called sluggin the frame and is ultra strong. Also a good idea to plug weld the bolt in the frame.

  7. #7
    Join Date
    Nov 2006
    Location
    southern oregon
    --
    2,338
    Quote Originally Posted by BigGreenMachine
    I vote KDX. WOuld be a nice trail machine with some power. Much more suited to woods then the 84 T3. I have an engine cradle you can have for cost of shipping. Its a KX500 cradle but it should work. I'll cut off the bottom mounts as one is broken and its been fixed using a washer.
    If I use the '85 KX engine..I may be interested in the cradle... But If I use the KDX engine, I may as well use the cradle I have... since the frame is useless without the engine..
    2-stroke lover

  8. #8
    Join Date
    Nov 2006
    Location
    southern oregon
    --
    2,338
    Quote Originally Posted by BigGreenMachine
    Joining frames is easy. Find a bolt that fits snug inside the frame tubing, cut the head off and tap it in the old frame so that the new section of frame can be slid over it. Leave about an eigth of space between the two frames so the bolt is exposed and weld the groove. Its called sluggin the frame and is ultra strong. Also a good idea to plug weld the bolt in the frame.
    This is the kinda info I am looking for.. It makes perfect sense. Would a MIG weld be strong enough? I am a decent welder(when I practice)...But I would rather blame someone else if it breaks...lol..
    2-stroke lover

  9. #9
    Join Date
    Nov 2003
    Location
    Newfoundland
    --
    5,281
    MIG is perfect for it CR. Any shop can do it if you'd rather them look after it.

    With the slug and good penetration it will be plenty strong.

  10. #10
    hadar's Avatar
    hadar is offline Just Too Addicted Arm chair racerJust too addicted
    Join Date
    Sep 2004
    Location
    Rock Island IL
    --
    699
    Someone correct me if I'm wrong but doesn't the KDX motor have a shorter stroke than the 88kx? I allways thought it did.

  11. #11
    Join Date
    Nov 2006
    Location
    southern oregon
    --
    2,338
    Quote Originally Posted by hadar
    Someone correct me if I'm wrong but doesn't the KDX motor have a shorter stroke than the 88kx? I allways thought it did.
    Its a KDX 250 that I am using.. They are both 67.4mm X 70mm... You may be thinking of the KDX 200/220...
    2-stroke lover

  12. #12
    hadar's Avatar
    hadar is offline Just Too Addicted Arm chair racerJust too addicted
    Join Date
    Sep 2004
    Location
    Rock Island IL
    --
    699
    Quote Originally Posted by cr480r
    Its a KDX 250 that I am using.. They are both 67.4mm X 70mm... You may be thinking of the KDX 200/220...
    Yep, I was.

  13. #13
    Join Date
    Nov 2006
    Location
    southern oregon
    --
    2,338
    Its final. I am using the KDX/KX 250 engine and cradle. The frame is going under the knife in 2 weeks. I had talked myself out of the swap(I was scared), until my old high school buddy offered to trade labor with me. He is a great fabricator. He builds dwarf car and dune buggy frames for fun and will make short work of my little project...
    Last edited by cr480r; 01-24-2008 at 08:33 AM.
    2-stroke lover

  14. #14
    Join Date
    Nov 2003
    Location
    Newfoundland
    --
    5,281
    Sweet! Sounds like a good build for sure! That motor is going to be strong.

  15. #15
    Join Date
    Nov 2006
    Location
    southern oregon
    --
    2,338
    The frame work has begun... It isn't going to be as simple and clean as I had originally thought.. but I am still pleased with it... The build-up will begin very soon...
    2-stroke lover

//ArrowChat Integreation Code //