Eagler's Nest

General Category => Off Topics and General Interest => Topic started by: Murray Randall on February 21, 2016, 04:24:18 PM

Title: Mukuni Carb Springs
Post by: Murray Randall on February 21, 2016, 04:24:18 PM

There have been at least a couple of complaints over the throttle closing springs in the Mikuni carbs.  I haven't started my engine yet but when winter breaks in Mass I should be ready.   I don't like the throttle feel that I have now.   Before I run off and do something stupid I want to get feedback.   I do not like the HIGH closing force of those springs.  So my plan is to  measure the stock spring and wind some springs.   Push down a half inch, measure the force on the digital scale.  I think I'm looking to get something maybe 1/3 of the stock spring. You do want enough spring force to over come friction in your cable system.  Stuck open though is not the worst thing that can happen to you.  There are several on line sources for 3 foot long pieces of spring steel from .005 inch on up.   Cheap enough stuff to experiment with. Please post or send to me directly your thoughts and advice.    Murray Randall  

Title: Re: Mukuni Carb Springs
Post by: Hugh Sistrunk on February 21, 2016, 04:50:40 PM

Hey Murray,
I had the same problem with my Mikuni Carb springs being 'heavy' also.  Not sure where I read it, but this matter has been addressed before and the solution was to shorten the existing springs.  I shortened my springs by about 25%, a couple of turns for my springs, then flattened the cut portion of the spring, with a Dremel wheel, so there was not a sharp edge cutting into the cap of the carb.  This made the throttle pressure a lot more manageable and kept the throttle in place with standard friction on the quadrant.  It made sense to me after someone pointed out the stronger springs were in place on these carbs to keep the slides in place during rough terrain dirt bike rides.  Not sure if that was the real reason, but I bought it hook, line and sinker... the cut springs work for me - your mileage may vary.........

Title: Re: Mukuni Carb Springs
Post by: Bob S. on February 21, 2016, 05:49:59 PM

Exactly what I did with my springs, Hugh. Works good!

Title: Re: Mukuni Carb Springs
Post by: Hugh Sistrunk on February 21, 2016, 09:45:30 PM

Hey Bob, How you doing dude?? Oh better mention carb springs or something :-)

Title: Re: Mukuni Carb Springs
Post by: Murray Randall on February 22, 2016, 05:09:08 AM

Many thanks that sure is a whole lot easier than my foolishness.