Logo
FULL SITE MENU

Recent content by MATPOC

  1. M

    BF90D overheating at WOT

    I'll drop the motor this weekend, got better bolts from McMaster, hopefully those don't need to be cut off every time. Water pump is easy enough as well so I'll get that done over the weekend
  2. M

    BF90D overheating at WOT

    My issue with this logic is that it only overheats at WOT (5,800 rpm) I can run at 90% throttle at 5,500 all day long and it flows enough water to cool the engine right up untill that last 10% Also tried different prop, went from 15p to 17P and it would not get past 5,000, but I could run WOT...
  3. M

    BF90D overheating at WOT

    What could possibly be wrong with the water pump assembly if I get a strong telltale stream at idle and water coming out of every hole? I loosened up the thermostat with engine running and the water came pouring out
  4. M

    BF90D overheating at WOT

    I bought this engine used and have gone through a number of issues, it's a later DK4 engine that was originally NMEA compatible and was converted to older electronics (DK0 or DK2) I have gone though the entire parts list and replaced all the non-compatible parts that were left behind (O2 and oil...
  5. M

    BF90D running issues, surging or stumbling at mid range

    Finally!! I have progress!! Bought a whole spare BF90D (2007) swapped the ECU from it and the miracle happened, it's no longer lean at 2,000 and the 02 sensor switching 3X faster. My guess is that ECU that I have was defective from factory, Honda doesn't even list that part number as a valid...
  6. M

    BF90D running issues, surging or stumbling at mid range

    Went back out with the two of us and I still can't get past 4,800 with new prop, gonna go back to the old one and test again, but that will be next week. Meanwhile I was able to spend decent amount of time at various RPM and watch the data and here's what happens which makes no sense. Attached...
  7. M

    BF90D running issues, surging or stumbling at mid range

    I wasn't able to go through full range of testing, mainly check for overheat at 5,800 rpm; we had guests and when I took it out with a new 17 pitch 3 blade prop and extra 800 lbs of weight I wasn't able to get past 4,300 rpm, so I'll try with less weight, if it doesn't get to 5,800 I'll go back...
  8. M

    BF90D running issues, surging or stumbling at mid range

    Replaced both thermostats, still overheating after a minute or two at WOT, I guess a vinegar bath is next? . Got Heal-tech hooked up and O2 is mostly hovering around .900 but at times drops to 0 and stays there. I see 3 ECTs on the engine, but data stream has 4 and the last one is reading -40ºC...
  9. M

    BF90D running issues, surging or stumbling at mid range

    My engine is a later model DK4 and has a 1300000 serial number while ECU is from older engine, DK1 or DK2, with 1000000 or 1100000 serial numbers. Also, Honda lists three different oil pressure sensors for the same serial number... I'd say it helps to understand why they change serial numbers...
  10. M

    BF90D running issues, surging or stumbling at mid range

    Do you know if those sensors I listed are backwards compatible? 003 is for the older PRE-NMEA ECU that I have and -H01 of for the 2017 and up, only $20 difference from Yumbo, quite a bit more when buying here in US
  11. M

    BF90D running issues, surging or stumbling at mid range

    why does it only happen at certain RPM range? I would expect it have minor impact, but RPM change is pretty significant before it fully warms up. I'll order O2 just to be sure, but it may take a while coming from Yumbo, also Honda has two sensors listed for the same motor, looks like one is...
  12. M

    BF90D running issues, surging or stumbling at mid range

    One more trip to the lake last night and I think I'm starting to understand that this is an array of issues instead of the single one, and some are possibly created by me trying to fix things. My initial thought was that I will find something what will be an "aha!" moment led me on the path...
  13. M

    BF90D running issues, surging or stumbling at mid range

    I just realized that my earlier search for DTC26 might have been a victim of Ai or wishful thinking, pretty it told me "oil pressure signal" because I had it unplugged, I just searched again and it gave me a generic answer "sensor out of range" but in reference to ECT. I have a manual for BF90D...
  14. M

    BF90D running issues, surging or stumbling at mid range

    When VTEC kicks in there's a pressure drop because when the spool valve opens it sends oil down to the actuators, think of a shower faucet when someone flushed the toilet, I just don't know what it needs to see on the sensor inputs at that moment. Waiting for 2 wire sensor and plug, it should be...
  15. M

    BF90D running issues, surging or stumbling at mid range

    Just talked to my old friend at Honda (car) dealership where I used to work, and he is the guy who actually knows how things work internally, not just a parts swapper... According to him on the 2 sensor engine the 1 wire is for the idiot light but the 2 wire sensor is used to monitor VTEC...
See more
Back
Top