1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Project My project MC22

Discussion in 'Your 250cc Projects' started by Krompot, May 21, 2020.

  1. DannoXYZ

    DannoXYZ Well-Known Member

    Messages:
    191
    Likes Received:
    91
    Trophy Points:
    228
    Joined:
    Sep 7, 2017
    Occupation:
    IT Manager
    Location:
    S.F. Bay Area
    My Bike:
    Honda CB125TT, Kawi EX250E, EX250F, EX250J street, EX250J race, Honda CBR250RR-MC19 x2,NSR250R-MC21 VF500F, CBR600RR, VFR750F
    Yeah, easy to get HT leads mixed up too! But I was thinking of wires from ignitor to coils themselves.

    [​IMG]

    Notice that both igniter trigger wires going to coils are YEL/BLK, but they are NOT interchangeable. Coming out of igniter, 1+4 trigger is yel/blk and stays yel/blk all way to coil. However, 2+3 trigger is BLK/YEL coming out of igniter and turns into YEL/BLK after final connector.

    So go back to very source, igniter itself, and trace each blk/yel and yel/blk wire all way to coils and make sure each one is connected to proper coil.
     
  2. DannoXYZ

    DannoXYZ Well-Known Member

    Messages:
    191
    Likes Received:
    91
    Trophy Points:
    228
    Joined:
    Sep 7, 2017
    Occupation:
    IT Manager
    Location:
    S.F. Bay Area
    My Bike:
    Honda CB125TT, Kawi EX250E, EX250F, EX250J street, EX250J race, Honda CBR250RR-MC19 x2,NSR250R-MC21 VF500F, CBR600RR, VFR750F
    Thing that concerns me is what happened between when 3-cylinders were working and now with none of them firing. What changed???
     
    • Agree Agree x 2
  3. Krompot

    Krompot Active Member Premium Member

    Messages:
    62
    Likes Received:
    15
    Trophy Points:
    78
    Joined:
    Feb 18, 2020
    Gender:
    Male
    Location:
    New Zealand
    My Bike:
    CBR250RR, Hornet 900
    Yeah they're wired up correctly. Each HT lead says which cylinder it goes to. 1/4 is wired to Y/B and 2/3 is B/Y. I just tried reversing them but no change.

    The spark is normal (between the two prongs) when i press the threaded bit against the frame. It jumps when i hold it away from the frame. Doesn't jump from in-between the HT lead and the plug.

    The bike was running on 3, (but this would change between cylinders overnight) i took the carbs off and tried to clean them but couldn't do much because #2 mixture screw was seized. Put them back on and bike wouldn't run at all. Got carbs off a running bike and still nothing. I'll mess around with those carbs today - start with 1 mixture screw turn and go up quarter of a turn all the way to 2.5 turns. I have new CDI installed.

    Edit: Push start did nothing.
     
    Last edited: Aug 8, 2020
  4. Krompot

    Krompot Active Member Premium Member

    Messages:
    62
    Likes Received:
    15
    Trophy Points:
    78
    Joined:
    Feb 18, 2020
    Gender:
    Male
    Location:
    New Zealand
    My Bike:
    CBR250RR, Hornet 900
    Update: took carb mixture screws out to 3 turns, tried with and without choke. I cranked bike for 20 seconds without carbs attached to try make sure they weren't flooding. I waited for the starter motor to stay somewhat cool in-between each adjustment.

    I noticed that there is still fog coming out of the cylinders even without the carbs on... What is that? It's still only cylinders 1,3,4. I initially thought that was fuel but it doesn't change even without the carbs on.
     
  5. maelstrom

    maelstrom LiteTek Staff Member Premium Member 250cc Vendor Contributing Member

    Messages:
    4,415
    Likes Received:
    2,939
    Trophy Points:
    923
    Joined:
    Dec 23, 2012
    Gender:
    Male
    Location:
    Thailand
    Home Page:
    My Bike:
    Yamaha FZR400 3TJ1, Honda MC22
    This engine has a new head gasket and you checked the flatness of the cylinder and block with a straight edge?
    You don't need to crank it for 20 seconds, 5 is enough.
     
  6. Krompot

    Krompot Active Member Premium Member

    Messages:
    62
    Likes Received:
    15
    Trophy Points:
    78
    Joined:
    Feb 18, 2020
    Gender:
    Male
    Location:
    New Zealand
    My Bike:
    CBR250RR, Hornet 900
    Yeah new head gasket. I don't have a dial indicator etc but i used a metal ruler and it seemed ok. There isn't any coolant in the bike while im working on it. Radiator gets in the way. Thanks.
     
  7. jmw76

    jmw76 Well-Known Member Premium Member

    Messages:
    668
    Likes Received:
    315
    Trophy Points:
    348
    Joined:
    Mar 12, 2017
    Gender:
    Male
    Location:
    Melbourne, Australia
    My Bike:
    Honda cbr250rr mc22 road + 1 track, Honda RC 162 tribute bike, Honda Spada Vt250, Honda CBR900RR
    When you say fog, where is that coming from? Is that out of the plug holes without the plugs installed? Water vapour maybe???. Is the water level in the cooling system going down?
     
  8. Krompot

    Krompot Active Member Premium Member

    Messages:
    62
    Likes Received:
    15
    Trophy Points:
    78
    Joined:
    Feb 18, 2020
    Gender:
    Male
    Location:
    New Zealand
    My Bike:
    CBR250RR, Hornet 900
    Out of the exhaust ports. There Isn't any coolant in the system. Here's the video:
    This is with the carbs on but it does the same with them off.
     
  9. maelstrom

    maelstrom LiteTek Staff Member Premium Member 250cc Vendor Contributing Member

    Messages:
    4,415
    Likes Received:
    2,939
    Trophy Points:
    923
    Joined:
    Dec 23, 2012
    Gender:
    Male
    Location:
    Thailand
    Home Page:
    My Bike:
    Yamaha FZR400 3TJ1, Honda MC22
    Sounds dry. When you used a spray bottle with gasoline in it and sprayed the mist into the carb mouths what happened?
     
  10. Krompot

    Krompot Active Member Premium Member

    Messages:
    62
    Likes Received:
    15
    Trophy Points:
    78
    Joined:
    Feb 18, 2020
    Gender:
    Male
    Location:
    New Zealand
    My Bike:
    CBR250RR, Hornet 900
    Nothing

    Edit: if i hold a lighter at the exhaust ports it lets out a big flame whenever the engine turns over so there is fuel coming out. Does this for all 4 cylinders.
     
  11. maelstrom

    maelstrom LiteTek Staff Member Premium Member 250cc Vendor Contributing Member

    Messages:
    4,415
    Likes Received:
    2,939
    Trophy Points:
    923
    Joined:
    Dec 23, 2012
    Gender:
    Male
    Location:
    Thailand
    Home Page:
    My Bike:
    Yamaha FZR400 3TJ1, Honda MC22
    Then that is the end of the carb discussion. Don't waste one second on them from here on in.

    It used to fire on 3 cylinders. Did it fire on any after you fitted the new TCI?
     
    • Agree Agree x 1
  12. Krompot

    Krompot Active Member Premium Member

    Messages:
    62
    Likes Received:
    15
    Trophy Points:
    78
    Joined:
    Feb 18, 2020
    Gender:
    Male
    Location:
    New Zealand
    My Bike:
    CBR250RR, Hornet 900
    Nah i only put the new TDI on yesterday. Could the ignition pick-up be the issue? It's 40 ohm out of spec...
     
  13. maelstrom

    maelstrom LiteTek Staff Member Premium Member 250cc Vendor Contributing Member

    Messages:
    4,415
    Likes Received:
    2,939
    Trophy Points:
    923
    Joined:
    Dec 23, 2012
    Gender:
    Male
    Location:
    Thailand
    Home Page:
    My Bike:
    Yamaha FZR400 3TJ1, Honda MC22
    First of all, I posted the gasoline in a squirt bottle on the 29th. 10 days later you give the answer and only after I ask again, so all the time wasted by everyone including yourself on the carbs. We are not there. We have to rely on the information that you give us.

    Now from one of my previous posts
    You maintain that it has good spark. I have not seen a video of the fat blue spark occurring at the spark plugs so we have to take your word for it. That leaves timing and it is fixed by the trigger and the TCI. At this stage I would be going with Occam's Razor, swap out the trigger or use a strobe light to check the timing.
     
    Last edited: Aug 8, 2020
  14. maelstrom

    maelstrom LiteTek Staff Member Premium Member 250cc Vendor Contributing Member

    Messages:
    4,415
    Likes Received:
    2,939
    Trophy Points:
    923
    Joined:
    Dec 23, 2012
    Gender:
    Male
    Location:
    Thailand
    Home Page:
    My Bike:
    Yamaha FZR400 3TJ1, Honda MC22
  15. kiffsta

    kiffsta Administrator Staff Member Contributing Member Dirty Wheel Club

    Messages:
    8,923
    Likes Received:
    6,691
    Trophy Points:
    1,168
    Joined:
    Aug 7, 2010
    Gender:
    Male
    Occupation:
    I make bad bikes go to heaven
    Location:
    Brisbane
    Home Page:
    My Bike:
    90 CBR250RR, 1973 Suzuki GT380 and a 1995 CBR900RR
    what marklings are on on your CDI/ tci ? , the L and the N miodel should have KAZ and on the r model should be kazg
     
  16. Krompot

    Krompot Active Member Premium Member

    Messages:
    62
    Likes Received:
    15
    Trophy Points:
    78
    Joined:
    Feb 18, 2020
    Gender:
    Male
    Location:
    New Zealand
    My Bike:
    CBR250RR, Hornet 900
    Hello again - I have decided to give this another go. Properly this time...

    Would anyone be able to provide me with some info regarding hornet engines? Are all the CBR250 I4 bottom end parts interchangeable? I'm aware of camshaft/carburetor differences.

    My diagnosis of the engine currently: Spun big-end bearing on cylinder #3 because of inadequate oil. (my fault, didn't check the radiator nor oil levels for a few months.) I suspect a warped crankshaft. I say this because it turns smoothly for ~300 degrees then gets real tight the remaining 60 (enough so it won't crank via starter). I can also hear it touching and lifting when I spin it inside the engine case. I think it may have bent from the heat, though I did drop it off the table the first time I disassembled the engine. Lol.


    Low (95-105) PSI across all 4 cylinders because I didn't set the ring gap. I have ordered new rings, new bearings, valve shims. Head isn't warped. Valves don't leak. New oil pump already.

    What do you guys do if you were in my shoes? Should I buy a crankshaft or a whole engine?

    I apologize for my childish impatience previously. Thanks for all your help.
     
    • Bummer Bummer x 1
  17. Murdo

    Murdo The Good Doctor Staff Member Contributing Member Ride and Events Crew

    Messages:
    5,897
    Likes Received:
    4,437
    Trophy Points:
    1,148
    Joined:
    May 4, 2013
    Gender:
    Male
    Occupation:
    Retired
    Location:
    Tamworth, NSW
    My Bike:
    1938 Royal Enfield 250, CF Moto 250 V5, Honda's XL250, CBR250, VT250F2, FT500 plus a few others.
    Whole engine from a good running bike and swap it into your frame.
     
    • Like Like x 1
  18. maelstrom

    maelstrom LiteTek Staff Member Premium Member 250cc Vendor Contributing Member

    Messages:
    4,415
    Likes Received:
    2,939
    Trophy Points:
    923
    Joined:
    Dec 23, 2012
    Gender:
    Male
    Location:
    Thailand
    Home Page:
    My Bike:
    Yamaha FZR400 3TJ1, Honda MC22
    1/ The crank would not have warped from heat.
    2/ You only need to set the ring gap if they are tight.
    As Murdo said, fit another engine.
     
    • Agree Agree x 2
    • Like Like x 1
  19. Krompot

    Krompot Active Member Premium Member

    Messages:
    62
    Likes Received:
    15
    Trophy Points:
    78
    Joined:
    Feb 18, 2020
    Gender:
    Male
    Location:
    New Zealand
    My Bike:
    CBR250RR, Hornet 900
    lol... pulse generator bolt was on there tight. The crank's bent anyway.
    [​IMG]

    So:

    Bought a good MC17 (140/150/140/150) engine ($200), the only MC22 engine I could find was $1000. No thanks.

    Putting the crank + pistons into the MC22 case, swapping the MC22 pulse generator onto the MC17 crank + reusing the MC22 head. Good condition oil pump from AUS. I have a set of rings lying around but I decided to use the ones from the MC17 engine, it had 20k km. OEM > China.

    The Head has been torqued down (I know!! I finally bought a torque wrench!!). Tomorrow I do the valve clearances and give her a go.
     
    • Like Like x 1
  20. Krompot

    Krompot Active Member Premium Member

    Messages:
    62
    Likes Received:
    15
    Trophy Points:
    78
    Joined:
    Feb 18, 2020
    Gender:
    Male
    Location:
    New Zealand
    My Bike:
    CBR250RR, Hornet 900
    I have good news and I have bad news!

    Good news:
    150 on #1, #2 and #4. 145psi on #2
    20210611_133250.jpg

    Bad news:
    Bike goes full churn for a second or two after startup, sounds awesome. Then, as my luck would have it, it drops to 3 cylinders for maybe one or two seconds, then it's just cylinders 1 and 4 firing and stays that way. It only 'idles' with 2.75 turns on the idle screws (1.75 is stock) or with full choke. It seems with full choke cylinders 2/3 are doing something (the exhaust pipes are hot-ish to the touch) though are much colder than 1/4 and it sounds like it's running on 2.5 cylinders.

    I did swap the coils+leads around, and the issue persists, so it's not the coils themselves.
    Could there be an issue with the power supply to the 2/3 coil? Any way to measure this?
    From what I could see with my naked eye, the spark colour looked the same between the coils. I checked them one at a time, leaving the other 3 attached (to put a load on the system). I should probably take a video of it.

    If I wait for a minute or two the same thing happens, where it goes full churn -> 3 -> 2.

    The problem persists when I connect the bike to a big ol' boat battery with jumpers.

    I sprayed a tiny bit of petrol into the carbs as it was 'idling' and it made a big difference, so I do in fact think it is fuel.
    I believe the reason why this did nothing earlier is due to the low compression, and possibly even weak spark. I'll take photos of the spark colour tomorrow.

    I have ordered a full carb rebuild kit from XCite bikes. I'll keep you lads updated! I'm feeling hopeful!
     
    Last edited: Jun 12, 2021

Share This Page