vm40 mikuni carbs info - Snowmobile Forum: Your #1 Snowmobile Forum

User Tag List

LinkBack Thread Tools Display Modes
post #1 of 3 (permalink) Old 02-10-2013, 08:25 PM Thread Starter
Registered User
Join Date: Feb 2013
Location: Canada
Posts: 2
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
vm40 mikuni carbs info

Hey all, i'm new to the site and need some help setting up an older engine. It's a complete rebuild 91 617cc with vm 40 mikuni carbs, my question is what should the jets and needle/seat's, as well as needle valves and valve needles be?. I currently have 2.0 needle and seats, 35 pilot jets, 420 main jet on clutch side and 440 on mag side (it helps to distribute the heat more evenly) i cant see the digit's on the valve needle or needle valve, and im thinking its the issue to my 1/4 throttle bogging issue. I've installed new needle and seats and done a complete soak and clean on the carbs, and it still does it. Can any one verify the right jet and needle set up for this particular engine and carbs so i can be sure its correct?...and any suggestion as to my 1/4 throttle bogging issue would be great full as well...thanks all in advance.
mxznutz is offline  
Sponsored Links
post #2 of 3 (permalink) Old 02-10-2013, 09:25 PM
Registered User
Join Date: Sep 2011
Location: Ames Iowa
Posts: 114
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
air/fuel screws 1/2 turn IN (richer) ,see if it helps...make sure idles not too rich.
minisrint521 is offline  
post #3 of 3 (permalink) Old 02-11-2013, 03:42 AM
I am Spartacus
smallengineguy's Avatar
Join Date: Feb 2004
Location: Milton Mills, NH
Posts: 23,862
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
www.hlsm.com will give you all the carb specs.

1992 Ski Doo Mach 1 (SC-10/2 suspended) March '07 SF.com Sled of the Month! (Lost in fire 4-7-13)
2009 Ski Doo MXZ 500SS TnT
2006 Ski Doo MXZ 500SS
1999 Ski Doo MXZ600
Webmaster Evergreen Valley Snowmobile Club
SledNH.com Moderator
smallengineguy is offline  
Sponsored Links

Quick Reply

Register Now

In order to be able to post messages on the Snowmobile Forum: Your #1 Snowmobile Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome