77 LF

S_Kyle · Post by **S_Kyle** » Fri Dec 26, 2008 6:48 pm

i got my 77 440 LF last winter. Ran like a top no problems. i did some work to it this summer, and now I have a few little issues.

I pout oil down the holes this summer when I was finished with it. Now it likes to foul the first and sometimes second set of plugs in it. Once it fires it runs great. I just ran the firs part tank on fuel out of it. I put 40:1 i it and now am going to try 50:1 the same as last year. Could the extra oil cause the plugs to foul.

Next bit. what should a 77 LF be revving to. I got it on a snow packed road and gunned it I was around 8500 - 8700, and on trails I am running around 6500 for sustained periods. This sound correct?

Oh and I a using BR9ES plugs

Post by **ICCSF 108** » Fri Dec 26, 2008 7:43 pm

My Old 76-79 Fine Tune Manual say's 77& 78 440 Liquifires 6800 to 7300 Governed RPM, with AM54279 ( R ) (59.6 +/- .5 grams) Arm Kit, & Black Spring.
76 440 Liquifires 7250 - 7750 RPM,
Governed RPM means when you go from Idle to WOT the tach should go to this RPM & stay there while up shifting on hard pack or ice..
Keep in mind the tachs are only accurate +/- 10%
But it sounds like it's over reving a bit, maybe a worn or too long of a drive belt??
BR9ES might be a bit cold (which is OK but is probably why your fouling with the 40-1 mix) Personally I would use B9ES forget the ( R ) Resistor type plugs there more expensive & I think foul easier, at least my opinion.. I know they used to push these big time in Canada in the 70's along with the resistor type plug wire ends
Kenny

speedy295 · Post by **speedy295** » Sat Dec 27, 2008 4:44 am

Not to bark up the wrong tree, but Ive always had **** luck with NGK's. In dirtbikes, snowmobiles, and my turbo 4 bangers I playwith. I seem to have better luck with Champions, and believe it or not Autolites.

S_Kyle · Post by **S_Kyle** » Sun Dec 28, 2008 5:03 pm

Well it looks like I dropped the PTO side piston

. I went to drop n air box off for my cousins 81 lynx. As I drove up he blew the head gasket out of it. It was behaving similar to my LF so I went home and tested the compression, the gauge was acting stupid but I got around 100 mag side and 50 PTO side. I have to get a good tester but it looks like I a redoing the top end of liquifire.

The bottom end was done two years ago. So it looks like I have to tear the heads off and figure out what caused to melt down. Since it was over revving it only had 25 +- miles on it. Maybe a bit last year.

Let the saga begin.

, Looks like the Massey will be getting a few miles on it.

Scott

Post by **ICCSF 108** » Sun Dec 28, 2008 6:44 pm

If there is any debris setting on top of the crank it would be wise to split the cases, clean & flush the crank bearings & case halves, if it just seized a piston at the rings then you might get by with just flushing the case & crank out without splitting them???

Kenny

PS: Rich, why did Deere have the 76 - 440 Liquifires running @ 7250 -7750 with 180 mains & then have the 77-78 - 440 Liquifires running 6800-7300 with 220 mains. I did notice there was other carb changes, but the clutching was the same in all 3 years, except for the 44 deg cam in the 77-78's??? I'm just curious as to what led to that??

S_Kyle · Post by **S_Kyle** » Mon Dec 29, 2008 4:42 pm

The motor is not seized, it just has low compression in the PTO side. I just hope the cylinders are alright

. I have pistons already just need to measure the bore to see if they fit.

I think they sled will be down for the season as I wont have time till summer to do anything with it. Unless I pay to have it fixed

.

Scott

S_Kyle · Post by **S_Kyle** » Mon Dec 29, 2008 6:09 pm

So I guess I need head and base gaskets. Looked in EBay are M66829 for the base and M66840
for the head correct? That and the pistons rings and clips. Is there anything else I am for getting. I have never done this on my own but I have the service manual and can get some help/advise before I start.

harleysportster · Post by **harleysportster** » Mon Dec 29, 2008 6:44 pm

Scott,
Unless you have a sled lift, it is much easier to work on the engine after removal. Bending over for extended times will give you a back-ach.
Pointers and tools needed:
-collection pan for anti-freeze
-gasket scraper
-gasket sealer
-torque wrench
-shop rags
-assistance
Read the service manual completely before attempting any repair.
-removal of engine
-removal of head
-removal of mono-jug
-removal of pistons / or rings
-essembly
You won't really know what went wrong until after tear-down.

-

Post by **ICCSF 108** » Mon Dec 29, 2008 8:20 pm

Unless you caught part of a piston on the port & did damage to a port You should be able to just hone the cyl.s & be just fine with new pistons & rings as this engine has steel liners.

Kenny

S_Kyle · Post by **S_Kyle** » Wed Dec 31, 2008 8:14 pm

I hate to have to admit this but...

I had a bad compression gauge. I hauled it into a friends heated garage to check what went wrong. Just before I dumped the coolant I figured I better check the compression again to be sure. What do you know the same gauge now said that there was 90 pounds in the bad side and 110 in the good
:eek: . So I went and got another gauge from my friend and ended up with 123 psi PTO side and 125 psi Mag side

. So I looked else where, pulled the carbs and they were clean as a whistle.

I figure that the carbs must have been iced up? Let it sit over night and put fresh plugs in and it started first pull, and idled like a champ. Still have to figure out the over revving, but got a new belt today.

moontreenrg · Post by **moontreenrg** » Thu Jan 08, 2009 5:39 pm

measure twice cut once that sure saved you a lot of ache