GMCforum
For enthusiast of the Classic GMC Motorhome built from 1973 to 1978. A web-based mirror of the GMCnet mailing list.
Home » Public Forums » GMCnet » Re: [GMCnet] So, about removing the Onan heads and looking for carbon...
Re: [GMCnet] So, about removing the Onan heads and looking for carbon... [message #192742] Mon, 10 December 2012 20:30 Go to previous message
Marcus McGee is currently offline  Marcus McGee   United States
Messages: 112
Registered: March 2004
Karma:
Senior Member
Worked for me when I did it that way.

Marcus

----- Original Message -----
From: "Rob Mueller" <robmueller@iinet.net.au>
To: gmclist@temp.gmcnet.org
Date: Mon, 10 Dec 2012 21:27 -0500
Subject: Re: [GMCnet] So, about removing the Onan heads and looking for carbon...

> Robin,
>
> I'm going to suggest the following, HOWEVER, before you do it see what the general consensus is about the idea.
>
> 1) Screw four bolts back into the head at each "corner" leaving them about 1/8" away from the head.
> 2) Put the spark plug back into the head on that side,
> 3) Disconnect the leads from both spark plugs.
> 4) Hit the start button.
> 5) The compression should separate the head from the block.
>
> Regards,
> Rob M.
>
>
> -----Original Message-----
> From: Robin Hood
>
> Is there a trick to getting the cylinder head off once the 10 bolts
> and washers and nuts is accomplished? I can't seem to get it to budge.
> Also, the left side cylinder head cooling fins are COVERED in oil.
>
> http://youtu.be/CeExXjNEPUQ
>
> On Mon, Dec 10, 2012 at 3:59 PM, Rob Mueller <robmueller@iinet.net.au> wrote:
> > Robin,
> >
> > You can clean the carbon (black / brown stuff) off the heads and the top of the piston with Easy Off Oven Cleaner.
> >
> > The heads are easy:
> >
> > 1) Put several layers of news paper down on your garage floor
> > 2) Lay the heads on the newspaper with the carbon facing up
> > 3) Spray the heads with Easy Off
> > 4) Let it soak in and loosen the carbon
> > 5) Scrap / wire brush the carbon stuff off
> > 6) Spray them again if it all didn't come off
> >
> > The pistons are a bit tricky
> >
> > 1) Turn over the Onan until one of the pistons is all the way up in the cylinder
> > 2) Spray it with Easy Off
> > 3) Let it soak in and loosen the carbon
> > 4) Scrap / wire brush the carbon off
> > 5) Spray them again if it all didn't come off
> > 6) When all the carbon is off the piston take a can of WD-40 and spray it in the space between the piston and cylinder start at
> > 12:00 and go counter clockwise down to 6:00. Repeat going from 12:00 to 6:00 clockwise. Do this several time to get all the Easy
> Off
> > out between the piston and cylinder.
> > 7) Rotate the Onan enough to lower the piston about 1/2 inch in the cylinder and wipe the bore out
> > 8) Return the piston to its original position and repeat the WD-40 spray.
> >
> > I used this procedure on Harleys a lot and never had any problems.
> >
> > Regards,
> > Rob M.
> >
> > From: Robin Hood
> >
> > What am I looking for, exactly, and what do I do with it when I find it?
> >
> > I need to remove the Onan cover from over the heads and clean the cooling fins.
> > I need to take off the cylinder heads and "look for carbon" but I've
> > never done this before so I don't really know what I'm looking for.
> > Surely somebody has documented the process on the GMC photo site?
> > If there's any carbon, I have to clean it away. Whether this requires
> > chemicals or just a damp rag I don't know. Neither do i know what it's
> > even necessary in the first place... but I do know I don't want to get
> > back into my Onan once I've got it in the coach.
> > Need a carb kit from JimK just to be on the safe side. My chemdip
> > prolly ate the gaskets in the needle/seat (I didn't know that stuff
> > was removable),
> >
> > --
> > Robin
> >
> > _______________________________________________
> > GMCnet mailing list
> > Unsubscribe or Change List Options:
> > http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
>
>
> --
> Robin Hood
> Jackson, MS
> 2003 Buick Lesabre
> 1968 Pontiac Catalina
> 1978 GMC Royale motorhome
> 1977 GMC Palm Beach motorhome
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist

Report message to a moderator

[Message index]
 
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Previous Topic: [GMCnet] GMC Trailer
Next Topic: [GMCnet] New GMC Limo Service
Goto Forum:
  


Current Time: Sun Sep 29 10:40:47 CDT 2024

Total time taken to generate the page: 0.01102 seconds
.:: Contact :: Home ::.

Powered by: FUDforum 3.1.1.
Copyright ©2001-2021 FUDforum Bulletin Board Software