2001 Trail Boss wont run when cold fuel pump test? - Polaris ATV Forum
ATV General Discussion General Discussions about Polaris ATVs.

 
LinkBack Thread Tools Display Modes
post #1 of 1 (permalink) Old 01-21-2014, 07:08 PM Thread Starter
ATV Enthusiast
 
cerino2000's Avatar
 
Join Date: Sep 2009
Posts: 60
2001 Trail Boss wont run when cold fuel pump test?

Bought the machine not running. Needed battery guy said likely needed carb cleaned too. Ive cleaned what seems to be a million carbs and this one has me stumped. I have been in the carb literally 10 times in the last two days. When the machine is stone cold as in sitting overnight, it just wont fire. Shoot it with carb cleaner and it eventually will fire off.

One you get it fired the thing purrs like a kitten once warm. Will restart with a tap of the button. In fact runs perfect.

Youd think choke issue but it is physically working fine.

When it did it today i went back in the carb and there was plenty of fuel in the bowl.

On a side note in case anyone else is looking for the proper main jet size, the parts listing will say a 145 but the machine had a 120 in it. I put a 145 in it and things were no better and in fact then it was over jetted. It appears that the 120 is correct for some machines.

Plenty of spark. Tons of compression.

I also noticed that these things will not run right with the air box lid off. Ive read this and something about the 120 in some machines as well.

Ok...so fuel in the bowl, plenty of spark and compression. The three things that are required to run...and yet it wont.

So the air lid thing has me thinking. The machine seems as if it cant get a good enough draw onto the carb or something. Grasping at straws but thats my thought.

So maybe there is a vacuum leak? Intake boot is fine. The line coming off the carb going to the fuel pump appeared good at a glance but i haven't looked at it super close yet.

On to my question:

Is the fuel pump on these simply an on/off with engine vacuum turning it on? If i put a hard vacuum on it, it should hold it?

Any ideas on why this thing just cranks and cranks and cranks when stone cold?

Last edited by cerino2000; 01-21-2014 at 07:10 PM.
cerino2000 is offline  
Sponsored Links
Advertisement
 
Reply

  Lower Navigation
Go Back   Polaris ATV Forum > Polaris ATV Discussions > ATV General Discussion

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Polaris ATV 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:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


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

Email Address:
OR

Log-in










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



Similar Threads
Thread Thread Starter Forum Replies Last Post
How to test the on off fan sensor for trail boss 2010? sinful ATV Repair and Maintenance 5 04-21-2015 12:47 PM
2001 Sportsman 400, Fuel Pump Repair, Engine Dies, Fuel Issues GrumpyDude ATV Repair and Maintenance 0 07-31-2013 07:16 PM
'99 Big Boss 6x6, fuel pump problem beattie ATV Repair and Maintenance 0 08-29-2012 03:48 PM
2001 trailboss wont start, fuel issue, fuel pump? Judd ATV Repair and Maintenance 5 02-20-2011 08:05 AM
Fuel pump test?? Mark Foucher ATV General Discussion 6 01-25-2011 04:34 AM

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