Results 1 to 2 of 2
  1. #1

    Join Date
    Jun 2010
    Long Island, NY

    87' JS550 Mikuni Carb

    Hey guys, I was given an 87' JS550 in what i thought to be okay shape but was missing a few things here and there. Threw a battery in it and to my surprise it started but wouldn't stay running. It had sat for some time and i'm very new to this but I was planning on making this a project of mine. My first suspicion is the carb which I've researched and believe to be a 40mm Mikuni Carb. I know most of you guys say not to even bother rebuilding a BN and go straight for an SBN to save myself a headache. My question is can someone tell me if I have a BN or an SBN carb of my hands? I only ask because whoever owned this ski last took the time to make some modifications and I didn't know if the carb was one of them. (ski has a coffman pipe, sponsons removed)
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	IMG_0402.jpg 
Views:	326 
Size:	62.1 KB 
ID:	304022   Click image for larger version. 

Name:	IMG_0401.jpg 
Views:	765 
Size:	70.9 KB 
ID:	304023  

  2. #2

    Join Date
    Jun 2010
    Long Island, NY
    Stumbled upon a website that showed the difference. This is a Mikuni44BN which in so many words is junk. Looks like i'll be looking for an SBN as the next step to this project.

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. Mikuni Carb Spring Color and Gram Association
    By RX951 in forum Yamaha How To & FAQs
    Replies: 2
    Last Post: 04-14-2008, 09:34 PM
  2. How to identify different Mikuni carbs on SL780
    By martinv in forum Polaris PWC Performance
    Replies: 10
    Last Post: 05-08-2007, 01:35 PM
  3. Mikuni Carb Owners Manual/Service Guide
    By warnos16v in forum Yamaha How To & FAQs
    Replies: 5
    Last Post: 03-25-2007, 08:46 AM
  4. Need 80gram springs (2) for Mikuni carbs
    By qbzonk in forum Yamaha PWC Performance (2-stroke)
    Replies: 0
    Last Post: 01-13-2007, 02:44 PM
  5. Who's the guy(website) for Mikuni carbs kits?
    By GPKiwi in forum Yamaha Open Discussion
    Replies: 3
    Last Post: 10-30-2006, 03:03 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