Like Tree0Likes


Old 02-22-2008, 01:47 PM
Thread Starter
Join Date: May 2007
Location: Toronto Ontario
My Boats: 28 Pantera
Posts: 661
Default 500efi

I was wondering if some of you could give me some insight regarding these engines.
Common problems
Recommended Service Intervals
#hours before parts failure/ rebuild

I am looking at 2 boats and they both have 500EFI power.

Thanks in Advance
ar15meister is offline  
Reply With Quote
Old 02-22-2008, 02:07 PM
Join Date: Jan 2004
Location: Northern NY
My Boats: '06 35 Lightning Merc HP 525's aka The Black Biotch
Posts: 4,970

HP 500 EFI or carb are same basic animal, you can dig out a lot of info on here about them.

Basics, 200 hrs change the valve springs, spend some bucks and get quality springs, shims and retainers. Check the chit every season for signs of problems. Check the Crane roller rockers seasonaly and plan to replace around 200-250 hrs, or just change to the Crowers and forget them. Plan on changing the roller lifters around 250-300 hrs. Other than the valve train they are good motors, most all failures have been valve train related. When I had to rebuild mine it was a broken valve spring that caused it, dropped a valve, was very lucky did not do much damage other than mark the top of the piston, the internals were all fine, that was at 176 hrs. I would own them again, but would just use beter quality parts than Merc did in the valve train. A few xtra bucks will save you in the long run. Have someone do a leak down test on any you are looking at and you should be fine.

Last edited by RaggedEdge; 02-22-2008 at 02:10 PM.
RaggedEdge is offline  
Reply With Quote
Old 02-22-2008, 07:38 PM
Join Date: Jan 2005
Posts: 101
Default 500 efi's

I have had several of them and had no problems.
They are very reliable.
I have a friend that has 500 hours on his and he runs them pretty much WOT all the time.
O problems for him.
Depending on the boat they are pretty good on economy and you can run 87 octane in them which is nice.
I have been very pleased with mine.
specman is offline  
Reply With Quote
Old 02-22-2008, 07:42 PM
Charter Member #34
Charter Member
Dock Holiday's Avatar
Join Date: Oct 2000
Location: Beautiful North Carolina
Posts: 7,151

The best most reliable most race proven power plant in the marine industry.
Dock Holiday is offline  
Reply With Quote
Old 02-23-2008, 08:25 AM
Join Date: Jan 2004
Location: Jacksonville FL
Posts: 1,807

what about borring them over 30 over? do you start to see unreliabilty with small engine working
Boomer35 is offline  
Reply With Quote
Old 02-24-2008, 08:22 AM
Platinum Member
Join Date: Jan 2001
Location: PA and MD
My Boats: fuel injection, superchargers
Posts: 1,449

What do you do to the 500EFI to get to 620HP? Heads, cam? Cost?
cobra marty is offline  
Reply With Quote
Old 02-28-2008, 07:56 PM
Platinum Member
Platinum Member
Platinum Member
Top Ven's Avatar
Join Date: Jul 2007
Location: New Jersey
My Boats: Nor-Tech 390 Sport CC
Posts: 417

i have 280 hrs on my 500 efi in my Top Gun, i would like to get them to 620 hp, Who does that work ?
Top Ven is offline  
Reply With Quote

Related Topics
Thread Starter
Last Post
07-07-2006 07:11 PM
Prop Talk
06-19-2006 07:23 PM
General Q & A
10-05-2004 07:38 AM
10-07-2003 09:13 PM

Posting Rules
You may not post new threads
You may not 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

All times are GMT -5. The time now is 06:14 AM.

Copyright 2011 OffShoreOnly. All rights reserved.