Register

If this is your first visit, please click the Sign Up now button to begin the process of creating your account so you can begin posting on our forums! The Sign Up process will only take up about a minute of two of your time.

Follow us on Facebook Follow us on Twitter
Page 1 of 2 12 LastLast
Results 1 to 10 of 17
  1. #1
    Platinum Member Platinum Member ApachePete's Avatar
    Join Date
    Aug 2001
    Location
    Sarasota,FL & Saugatuck, MI
    Posts
    1,017

    HP 500 EFI Vapor-lock kit

    I bought 2 of the Merc retro-fit kits for my 1999 500 EFI's.

    Kit includes an one-way valve to prevent water from draining out of the block when the motor is not running, and an electric fuel pump to be installed prior to the fuel filter.

    My mechanic thinks the one-way water valve will cure my vapor-lock problem, and that the second electric fuel pump isn't necessary because all it can do prime the existing fuel pump.

    What do you guys think?

    Has anyone installed the kit?

    Do the post-1999 HP EFI's come with 2 fuel pumps?

    Thanks for any help you can offer!

  2. #2
    Registered
    Join Date
    Nov 2003
    Posts
    71
    I "believe" I have just purchased the same kit on E-Bay. Obviously not installed yet. I have had a considerable problem with vapor lock (2000 - 500 E.F.I.s) on the port motor. The search portion of this site will reflect numerous other confirmations that the kit will work. I made a recent inquiry that "Trouty" answered, again with praise to the kit. According to Merc. the 2 fuel pump models started in late 2001-2002 and the problem has been eliminated. I would also be interested as to the method/difficulty installing the kit.

    Also, I did isolate some of the problem, appears to be based on where the fuel was purchased.

    Lets PLEASE keep each other posted.

  3. #3
    Registered robyw1's Avatar
    My Boats:
    1998 Wellcraft 22' Scarab
    Join Date
    Jul 2003
    Location
    Spring, TX
    Posts
    2,756
    Okay I have to ask. Why is an EFI engine having vapor lock problems? Doesn't the fuel system have a return? In all of my years i have never heard of a modern fuel injected engine having a vapor lock problem. Please explain to me exactly what point in the fuel system is vapor lock taking place.

    Roby

  4. #4
    Platinum Member Platinum Member ApachePete's Avatar
    Join Date
    Aug 2001
    Location
    Sarasota,FL & Saugatuck, MI
    Posts
    1,017
    Yes, there is a return.

    I have no idea why the problem existed with the first production of this motor.

  5. #5
    Registered Von Bongo's Avatar
    My Boats:
    1997 Cig Kevlar - powered by Boyd
    Join Date
    Dec 2001
    Location
    Iowa - Missouri
    Posts
    3,893
    No, there isn't a return, at least not one put in by an OEM, not if it is coast guard certified. And that is why it is a problem with all Mercs EFI engines, not just the 500. Hence Cool Fuel and other fixes from Merc like letting it idle to cool down, keeping the hatch open when stopped to let heat escape and so on...it is a well documented problem.
    Last edited by Von Bongo; 12-13-2003 at 05:59 PM.

  6. #6
    Rob VIP Member Strip Poker 388's Avatar
    My Boats:
    Hustler 388
    Join Date
    Aug 2001
    Location
    Madison,Mississippi
    Posts
    21,460
    So these kits are for pre 2001 fuel cool systems?

    Mine has the fuel coolers and the by pass goes back to the fuel water seperator.
    .

    SBC Hydrocephalus

  7. #7
    Registered
    Join Date
    Nov 2003
    Posts
    71
    Its my understanding the problem was significant enough that the factory has since gone to the the mechanical fuel pump back on the water pump, AND the electric one located with the cooler under the motor 2001+. The fix, other than changing out the older water pump to the new model w/the fuel pump, is this retro kit. Please help, are we on the right track, and as Apache Pete as referenced, those that may have completed this retro, how difficult, and any pointers.
    Thanks

  8. #8
    Platinum Member Platinum Member ApachePete's Avatar
    Join Date
    Aug 2001
    Location
    Sarasota,FL & Saugatuck, MI
    Posts
    1,017
    ttt

  9. #9
    Platinum Member Platinum Member ApachePete's Avatar
    Join Date
    Aug 2001
    Location
    Sarasota,FL & Saugatuck, MI
    Posts
    1,017
    Troutly,

    Thanks.

    Nice new avitar!

  10. #10
    Registered
    Join Date
    Nov 2003
    Posts
    71
    Update. Please help guys. I have received the correct retro kit as provided by Merc., instructions are vague at best. Particular confusion with the anti siphon valve, says to change existing one (where is this one) with a provided electric one. Also, I could use further clarification regarding the provided wiring harness. The new pump is appears pretty easy. Any help would be appreciated.

    Thanks


Page 1 of 2 12 LastLast

Similar Threads

  1. 500 efi fuel pumps and vapor locking
    By Velocity Tom in forum General Boating Discussion
    Replies: 3
    Last Post: 04-13-2008, 11:24 AM
  2. 96 502 efi vapor lock?
    By cloudmaster_321 in forum General Q & A
    Replies: 1
    Last Post: 09-07-2006, 07:20 PM
  3. 95 502 efi vapor lock??
    By bj502 in forum General Q & A
    Replies: 12
    Last Post: 03-15-2004, 08:12 PM
  4. Vapor lock? Hydro lock? All I know is motor is locked. What do I do?
    By Pure Energy in forum General Boating Discussion
    Replies: 10
    Last Post: 07-22-2002, 11:56 AM
  5. EFI Vapor Lock
    By 32storm in forum General Q & A
    Replies: 10
    Last Post: 07-04-2002, 01:04 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
OSO Sponsor
OSO Advertisers


OSO Directory
All times are GMT -5. The time now is 11:00 PM.
Powered by vBulletin® Version 4.2.0
Copyright © 2014 vBulletin Solutions, Inc. All rights reserved.
Search Engine Optimization by vBSEO 3.6.1
Original Poster In Postbit provided by Original Poster In Postbit v1.0.0 (Free) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd. Runs best on HiVelocity Hosting.
Copyright 2011 OffShoreOnly. All rights reserved.