Just Another Mikuni Carb Rebuild Thread

[TrailR]

The Tiger was not in a happy state and in need of some attention on the carbs.  It has been too long since I have had to work on a bike with carbs, but so goes the ownership of a Steamer.

A big hat tip to Mustang for his excellent set of steps in this link:

http://www.tigertriple.com/forum/index.php/topic,7600.msg52526.html#msg52526

Here is some additional information that I was able to gather that may aid others taking on this step.  My bike has 7,600 miles, but all of the rubber bits were hard and crusty.  Not much actual cleaning was required, so that was the easy part.

Parts
Here are the bits you will need to complete this task along with the o-ring sizes (ID x thickness).  I have also included the McMaster-Carr part number for those in the US.

Mixture Screw - 3mm x 1mm (http://www.mcmaster.com/nav/enter.asp?partnum=9263K511)

Float Frame - 5mm x 1.5mm (http://www.mcmaster.com/nav/enter.asp?partnum=9263K121)

Float Valve Seat - 7.1mm x 1.6mm (http://www.mcmaster.com/nav/enter.asp?partnum=9263K137)

Slide Seat - 10mm x 1.5mm (http://www.mcmaster.com/nav/enter.asp?partnum=9263K295)

Vacuum Cap - 3.5mm x 1.5mm (http://www.mcmaster.com/nav/enter.asp?partnum=9263K564)

Stainless Cap Screws M5 x 12mm (http://www.mcmaster.com/nav/enter.asp?partnum=92290A228)

Stainless Cap Screws M5 x 14mm (http://www.mcmaster.com/nav/enter.asp?partnum=92290A230)

Float Needles - K&L Part #18-8944 (Source from your favorite eBay vendor)

Float Bowl Gasket - (Triumph or Suzuki)


Pictures

New o-rings for the float.



Pull out the slide and add an o-ring.  Don't forget to remove the main jet before you tug on the slide.



Mine has been touched before as evident by the various o-rings in use.  The new one is on the left.



Float Needles are a perfect match.  The old crusty one is on top.



New float needle is all happy.



Be sure to check your float height.  I made a quick gauge to check the setting.



Be sure to source a new float bowl gasket.  This was the main source of all my leaks.  Luckily the bike came with new gaskets ready to install.



New hardware to hold it all together.




The vacuum cap side is next.  Mine was missing all three of the vacuum o-rings.



Care should be taken with all of the small bits, a lesson I learned after I sent the spring spacer across the garage with a blast of compressed air.  I was able to source one from Suzuki...an exact match.





Finally the mixture screw.  This is the correct order of parts...ignore the Triumph manual.




One last closing piece of information.  If you do find yourself looking for parts, try a Suzuki dealer and tell them you have one of the following bikes (US models referenced):

1988-1989 GSX-R 750
1989-1992 GSX-R 1100
1988-1996 Katana 750

You may want to cross check with different years to make sure the part numbers stayed the same.

Best of luck!

[recroy]

Hi, Thanks for the carb info. I bought my steamer last year and its my 1st time dealing with mikuni's. Had a bad needle valve. My bike started life in Switzerland and made it to Canada via South America. I found it in Vancouver B.C. and fell in love! I'm a lifelong dualsporter and also own an '87 transalp. I live on Vancouver Island and am 160 km from the nearest triumph dealer, but only 3 km from a Suzuki dealer. You made my day! thanks!

[TrailR]

Glad to hear recroy!  I bought a bag full of o-rings from McMaster-Carr for the job, but you are probably better off buying the parts directly from Suzuki.  I figure I can now justify adding 6 more Triumphs into the garage to use all of my parts stock.   

[Bixxer Bob]

It's worth remembering that carbs, like a lot of bike parts (brakes etc) are off the shelf items to Triumph and other builders so spares are ofteneasierto get than you'd think.  We have a very good Mikuni specialist here in the UK who helped me out when rebuilding a Mikuni on an Aprillia.

[sweller]

We have a very good Mikuni specialist here in the UK who helped me out when rebuilding a Mikuni on an Aprillia.

Is that NRP in Manchester?

[Bixxer Bob]

No, it's Motocarb in Liverpool.  The contact details are in the stickies.

[recroy]

I ended up going to Canadian tire and was able to match up the O rings I needed. Worked out fine. Just some fine tuning and a carb sync and should be good to go!

[recroy]

BTW, I'm a newbie to this site and find it fascinating that there is so many die hard steamer fans here. I live on Vancouver Island and have not seen one other steamer yet! I know you're out there! I'd love to go riding with another tiger fan!

[John Stenhouse]

My orange 955 is on the island, tucked up in a friends garage 

[recroy]

Lots of awesome riding to do here! A dualsporters paradise!