Notices
General Boating Discussion

Merc. 420 eng. ?

Thread Tools
 
Old 12-15-2004 | 04:17 PM
  #11  
LapseofReason's Avatar
Thread Starter
Registered
 
Joined: Jan 2003
Posts: 2,806
Likes: 0
From: Stafford Va.
Default Re: Merc. 420 eng. ?

So maybe they are good motors, he says they use about a qt. of oil every20-25 hour's between changes.My 500 efi's did that from the start on 40 weight then stopped when I went to 20/50. I would think that a better set of valve covers might vent better and stop the dip stick thing.
LapseofReason is offline  
Reply
Old 12-15-2004 | 04:57 PM
  #12  
Registered
 
Joined: Jul 2002
Posts: 2,728
Likes: 8
From: Troy, Mich
Default Re: Merc. 420 eng. ?

LOR- I think the 420's are great engines but older. Have a compression chk done, make sure the 420's don't need rbuilding too.

Wannabe
wannabe is offline  
Reply
Old 12-15-2004 | 04:59 PM
  #13  
Formula Outlaw's Avatar
Registered
 
Joined: May 2003
Posts: 11,772
Likes: 0
From: In the Mountains
Default Re: Merc. 420 eng. ?

I've always heard they were great motors. Everyone I've ever talked to who runs them praises them. Got the good stuff inside and most get a lot of hours out of them with reasonable care.
Formula Outlaw is offline  
Reply
Old 12-15-2004 | 05:15 PM
  #14  
Registered
 
Joined: Jan 2004
Posts: 3,682
Likes: 4
From: Boca Raton, FL
Default Re: Merc. 420 eng. ?

A compression and leak-down test will tell you if these engines are internally healthy. Usually enough crankcase pressure to lift-out the dipstick is not a good thing. Did you say the oil was milky?
Edward R. Cozzi is offline  
Reply
Old 12-15-2004 | 06:54 PM
  #15  
Crazyhorse's Avatar
Registered
 
Joined: Jan 2001
Posts: 3,140
Likes: 0
From: Holland MI
Default Re: Merc. 420 eng. ?

All the factory 420 motors and 400 Cyclone Motors I've seen had springs on the dipsticks as well as the oil filler caps.
An engine survey is in order whenever you have questions about the health and well-being of the motors.
Crazyhorse is offline  
Reply
Old 12-15-2004 | 09:00 PM
  #16  
LapseofReason's Avatar
Thread Starter
Registered
 
Joined: Jan 2003
Posts: 2,806
Likes: 0
From: Stafford Va.
Default Re: Merc. 420 eng. ?

I'll be doing all the test for sure before I would buy or let a friend buy a motor, I just never heard the spring thing before. I think if he buys them they will get a nice set of KE valve covers to help with the crank case psi. They are still in the boat so we can even drive them then pull them.

Thanks for all the help, just wanted to hear what you all knew. They should be a nice upgrade from the whipped 454 mags. Witch will be for sale if anybody need's some motors that need to be rebuilt.
LapseofReason is offline  
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
First Gun
Swap Shop
1
09-11-2008 09:33 PM
MILD THUNDER
Northern Illinois Offshore Club
1
08-09-2005 01:31 PM
MILD THUNDER
General Boating Discussion
0
07-28-2005 08:19 PM
blown formula
General Q & A
32
11-20-2002 11:58 AM
Sean
General Q & A
9
03-27-2002 06:37 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



Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.