Damaged 1976 Liquifire 440

Deleted User · Post by **Deleted User** » Tue Nov 21, 2006 5:14 pm

Hello everyone,

I posted this in the other subject forums also, looking for as much advice as I can get. thanks.

Last season a friend of mine overheated my old 1976 Liquifire 440 which left it running very rough... no idling and once you let off the throttle it died. We tried all the small things first and nothing worked so we tore into the block the last few days. We removed the LH piston because it was damaged and the rings were all but destroyed. My first question to all you great sled mechanics is was this the result of the one night it was overheated leaving it hardly running??? And second is if I can locate this piston and rings is it as simple as slip the new piston in and some new seals and assume the problem is solved? Also there is some deposits on the side wall of that cylinder I assume from the damaged piston. What is the best way to fix this or when does one agree it is smooth enough?? Any suggestions and advice would be greatly appreciated. Before this sled was damaged it was a running machine in great shape. Thanks everyone.

harleysportster · Post by **harleysportster** » Tue Nov 21, 2006 7:15 pm

Farmkid,
Sorry to here of your misfortune. THe overheating could have caused the head gasket to fail, which could have leaned-out the fuel mixture or caused a pre-ignition condition.
The pistons are available from Dennis Kirk. If the only thing wrong with the cylinder is the aluminum deposit, that can be removed carefully scraping it off with a knife or bearing scraper. A solution of Sodium Hydroxide will remove the aluminum also.
If there are gouges in the cylinder walls, the new rings will not seal properly and a bore job is in order.
Since the rings were destroyed, it is wise to flush out the lower crankcase of any debris. This requires removing the engine and splitting the crankcase.
Before running the engine after assembly, it is wise to do a pressure test of the crankcase to check for any seal problems and fix it before running it.
http://s12.invisionfree.com/jdsleds/index.php?showtopic=431
Don't forget to check out why it overheated.
Check the coolant level
Check the cooling belt
Check the thermostat
Depending on the damage, it may be cheaper to find a good used cylinder and head. Check this guy out on Ebay.
http://search.ebay.com/_W0QQsassZruppmagnum1QQhtZ-1

400brian · Post by **400brian** » Wed Nov 22, 2006 3:13 am

I just want to emphasize a point Pat made. From every thing I have learned about 2 stroke engines, chemical cleaning of the aluminum deposit from the jug is not optional.

If you do not clean the aluminum from the steel cylinder liner, you will most likely experience another seizure ( in this case, a mini seizure ).

Muratic acid is another chemical that works ( pool supply ) Don't breath the vapors, this is nasty stuff.

Back in the day, your Deere mechanic would just put in a new jug and piston.

Mr. Deere · Post by **Mr. Deere** » Wed Nov 22, 2006 1:56 pm

HA HA HA SO TRUE

400brian · Post by **400brian** » Thu Nov 23, 2006 2:44 am

Yeah Rich, I know what you mean. After the " why the H*ll did this break?"
The guy will continue " I DIDN"T HARDLY HIT THAT ROCK!!"

As far as the jug repair: I scored a jug on the '72 400 back in 74 or 75. We took the engine down to the dealer in Madison WI. Pa said the jug just had a dull looking spot in it, but they replaced it with a new jug and piston. So that is what I am going by.