SoCal Jet Boats

Tech Talk => Engine Mechanical / Electrical => Topic started by: Luckie Stiff on August 10, 2011, 06:00:02 AM

Title: Lean is MEAN
Post by: Luckie Stiff on August 10, 2011, 06:00:02 AM
This is what happens with a combo of too much timing, sub standard gas & a loose nut @ the wheel...
Title: Re: Lean is MEAN
Post by: Nick on August 10, 2011, 07:29:54 AM
This is what happens with a combo of too much timing, sub standard gas & a loose nut @ the wheel...

Skip! Was that your engine? Time for a rebuild or just a repair?
Title: Re: Lean is MEAN
Post by: NORDIC454 on August 10, 2011, 08:58:24 AM
NICE!! I hope that's the only damage?
Title: Re: Lean is MEAN
Post by: obnoxious001 on August 10, 2011, 12:43:22 PM
This is what happens with a combo of too much timing, sub standard gas & a loose nut @ the wheel...

That's too bad,, did it get the block and head as well?
Title: Re: Lean is MEAN
Post by: Luckie Stiff on August 10, 2011, 01:31:23 PM
Block & head are fine, looks like I dodged a bullet this time. Just picked up my heads from the machine shop, nice 5 angle valve job, a little milling work and we're back in business. Combustion chambers are now 100cc
Title: Re: Lean is MEAN
Post by: pw_Tony on August 10, 2011, 07:03:44 PM
What caused it to go so lean?
Title: Re: Lean is MEAN
Post by: propless on August 10, 2011, 07:19:52 PM
 I'll stick with Fat and Happy.   ;)
Title: Re: Lean is MEAN
Post by: Luckie Stiff on August 10, 2011, 08:47:45 PM
What caused it to go so lean?

A number of small things added up to one big lean out. Timing was off (dizzy has since been rebuilt) giving me false timing, had waaaaaaaaaaaaaay too much in it. Carb had shit in the needle & seat, didn't allow full flow at higher rpm, throw in team Yellow Belly and you get the idea.
Title: Re: Lean is MEAN
Post by: obnoxious001 on August 10, 2011, 09:19:29 PM
I had an engine come to me once for a rebuild.  I was not the original builder.   When I put it back together I checked and found the timing mark (notch in the timing cover) was 6 degrees advanced.  Guess that explained the holes in two pistons (it was a blown engine)
Title: Re: Lean is MEAN
Post by: pw_Tony on August 10, 2011, 10:00:20 PM
A number of small things added up to one big lean out. Timing was off (dizzy has since been rebuilt) giving me false timing, had waaaaaaaaaaaaaay too much in it. Carb had shit in the needle & seat, didn't allow full flow at higher rpm, throw in team Yellow Belly and you get the idea.

That sucks, hard to catch the "small" things like that.

My timing marker is 4* advance as well Barry, checked it at TDC and made a new mark.
Title: Re: Lean is MEAN
Post by: farmergord on August 10, 2011, 10:22:15 PM
hope it wasnt as bads as you thought keep shaking that tree  >:D
Title: Re: Lean is MEAN
Post by: obnoxious001 on August 10, 2011, 10:31:02 PM
That sucks, hard to catch the "small" things like that.

My timing marker is 4* advance as well Barry, checked it at TDC and made a new mark.

I just put together a brand new all aluminum 621 cubic inch engine, with a brand new Milodon gear drive and ATI balancer.  The fixed pointer in the Milodon cover was 6 1/2 degrees retarded.  That one really surprised me with the high dollar parts,, but I went back and checked it several times to make sure.
Title: Re: Lean is MEAN
Post by: IRRebel on August 10, 2011, 11:09:55 PM
I just put together a brand new all aluminum 621 cubic inch engine, with a brand new Milodon gear drive and ATI balancer.  The fixed pointer in the Milodon cover was 6 1/2 degrees retarded.  That one really surprised me with the high dollar parts,, but I went back and checked it several times to make sure.

It's reasons like this I have my own initial timing method on BBF's and a Silver Sharpie marker.  I'm sure I can come up with one for BBC's too, if I ever really start really messing with them, but Barry's probably already got a short, sweet, easily field useable one to address stuff like this on bowties.

Never trust a timing mark, tab, pointer or the marks on a balancer until you PROVE they are right, is all I can add to this lesson. (Same with timing sets gang)  ;)

Skip, get the momo together, we got river cruising coming up in 10 days........

Ray
Title: Re: Lean is MEAN
Post by: obnoxious001 on August 11, 2011, 12:00:26 AM
, but Barry's probably already got a short, sweet, easily field useable one to address stuff like this on bowties.



I don't do it in the field, but you could use a dead stop in the #1 spark plug hole, along with your silver marker.

I always verify TDC before I bolt the heads on an engine, when I can use a dial indicator.
SMFPacks CMS 1.0.3 © 2026