Page 1 of 2 12 LastLast
Results 1 to 10 of 11
  1. #1

    BN44, SBN44, or something else?

    Going into my 5th season now with a 2005 1200 XLT and GP800R. A couple years ago, I had attempted to rebuild the carbs on both skis and found that they were corroded inside and out. Some of the paint was chipping off...there was literally sand caked in the fuel filter. I cleaned them up as best I could and used the rebuild kits that I purchased (off brand). I had some issues adjusting the 800 since I never did get a good count on the turns for the low/high adjustments. I got them "good enough" to use and they have been running fine up until now.

    I decided to break them completely down this past week and I was not very pleased with what I saw with the 1200.
    Click image for larger version. 

Name:	20150419_134336.jpg 
Views:	65 
Size:	75.9 KB 
ID:	357167Click image for larger version. 

Name:	20150419_142735.jpg 
Views:	66 
Size:	70.5 KB 
ID:	357169Click image for larger version. 

Name:	20150426_164129.jpg 
Views:	72 
Size:	93.3 KB 
ID:	357170Click image for larger version. 

Name:	20150426_175557.jpg 
Views:	71 
Size:	79.2 KB 
ID:	357171

    I have since blasted them...plan on repainting them and getting true Mikuni rebuild kits this time around. My question though is that I'm not really sure what type of carb this really is...for either ski for that matter. The manual(s) states that both skis have BN44's. The problem is that everything I've read so far tends to make me think that they're SBN44's instead since I've seen in multiple places that the jets in a BN44 are not replaceable/changeable and the carbs I have clearly can be changed:
    Click image for larger version. 

Name:	20150426_180141.jpg 
Views:	68 
Size:	103.1 KB 
ID:	357172

    I just want to be sure I know what I have before buying any replacement parts.

  2. #2
    Here are some pics of the initial blasting...more blasting and cleaning to come.
    Click image for larger version. 

Name:	20150426_210813.jpg 
Views:	66 
Size:	81.1 KB 
ID:	357173Click image for larger version. 

Name:	20150426_210910.jpg 
Views:	53 
Size:	46.0 KB 
ID:	357176Click image for larger version. 

Name:	20150426_210928.jpg 
Views:	65 
Size:	58.7 KB 
ID:	357177Click image for larger version. 

Name:	20150426_210832.jpg 
Views:	54 
Size:	87.0 KB 
ID:	357174Click image for larger version. 

Name:	20150426_210859.jpg 
Views:	59 
Size:	51.8 KB 
ID:	357175

    Oh...and the only discernable identification marker on them is the 4-09 that is stamped on them.

  3. #3

    Join Date
    Nov 2009
    send a pm to WFO
    He can sell you the kits you need.

  4. #4
    RaiderMagic's Avatar
    Join Date
    Aug 2013
    South Shore, Long Island NY
    Duude. Those were pretty bad.
    Do you use a fuel stabilizer? Using Stabil in every tank helps.
    Do you wash down the engine after riding? Try coating it with Fluid Film to prevent corrosion.
    A lot of people use Wd40 cause it's cheaper but it actually dries out to a sticky build up over time.

    Definetely oem oem only on the carb kits.

  5. #5
    Those look way better blasted than when they started! Since you're rebuilding/cleaning the carbs, make sure to pull the high and low adjuster caps so you can pull the adjusters out and clean those passages. It's hard, more likely impossible, to completely clean the carb w/o removing the caps and then the adjusters. I drilled, tapped, and used a screw through a probably 10mm socket to pull the caps out (each turn of the screw pulls the adjuster cap out some). I tried the other methods suggested on the site, but mine wouldn't budge.

    Dunno technically if they're SBN or BN44's as those names seem to be used interchangeably all over the place. Here's the mikuni manual for part numbers and stuff:

    I think I went to the parts site here and found the mikuni rebuild kit for the 66V engine. Didn't end up buying it though as by chance a guy on craigslist had 3 new unopened mikuni kits for $100. Sold his XLT I guess.
    Last edited by awh4992; 04-28-2015 at 03:57 PM. Reason: wrong carb manual link

  6. #6
    Bn44i. They are the I body

  7. #7
    Bn44/46i is the #. Buy them from cape fear item #181723476057 ebay

  8. #8
    Thanks for the replies all.
    I figured they were probably the "I" variant after finding this site:
    and noticing the rebuild kit MK-BN44I-YAM. I was pretty much face palming myself after I found that.

    As for the fuel stabilizer, I do use it, but not for all tanks. I also a few times out of the season end up getting fuel at the local marina which ends up being ethanol-free.

    As for the adjuster you really think it's necessary? Just saying...since because I've had issues with the 800 trying to get the adjustments right. This ski is more the 'family' ski, so not looking to make life too difficult for adjusting and such.

    I will be epoxying these things when I'm done, and then Fluid Film the entire engine before the season...I was lazy last year and forgot to use it...never again.

    This ski ends up upside down quite a bit in the OC MD bay due to my teenagers (and myself) hot-dogging it. Hose downs of the engine will be a new staple for it.

    I guess I just need recommendations for jetting/needle replacements. The current needles have slight indentations visible, so time for replacement...but not sure what these are or if there's a better setup.
    Current main idea what the other one is. Gold (tarnished) springs in each. Other than the D-Plate, ski is totally stock. I do pull a wake board/tube at times, so anything to help in that department would be a +.
    Click image for larger version. 

Name:	20150430_001530.jpg 
Views:	36 
Size:	59.9 KB 
ID:	357472

    Definitely going OEM with the new kits all the way.

    I can't wait to dive into the 800...

    Thanks again for all your help.

  9. #9
    dockwalker's Avatar
    Join Date
    Mar 2010
    On the water near Belhaven,NC
    You need to find some ethanol-free fuel.+1 on the Fluid Film.You did soda blast? Right?
    Check the late O'sideBill's posts for some jetting advice if pulling a tube.

  10. #10
    I at first tried soda, but it didn't seem to be working all that well. I'm guessing it was my setup. I used glass in the end and even that took longer than expected.

    After some more extensive reading last night, I am interested in pulling those caps now and modding the intake system as posted by OsideBill, but I'm concerned about water issues with the after market F/As if the ski gets put upside-down. I know I'll now try putting the F/As on the GP800R even though it goes upside-down every once in a while...the risk for playing in the ocean.

Page 1 of 2 12 LastLast

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Problem with rxt-x 260 or something else
    By rxp1972 in forum 4-Tec Performance
    Replies: 9
    Last Post: 07-20-2010, 11:16 PM
  2. Yamaha GP1300R vs STX15F (or something else)
    By Robbbin in forum Yamaha Open Discussion
    Replies: 1
    Last Post: 07-06-2009, 07:23 PM
  3. XPS oil (mixed with something else??)
    By johnson8537 in forum 2-Stroke Performance
    Replies: 4
    Last Post: 05-24-2009, 11:08 AM
  4. Starter relay prob... maybe something else?
    By BlitzK in forum Yamaha Open Discussion
    Replies: 3
    Last Post: 05-26-2008, 12:12 PM
  5. 07 RXP issue, prop or sc clutch or something else?
    By blandis in forum 4-Tec Performance
    Replies: 9
    Last Post: 09-08-2007, 06:35 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts