3120XP rebuild (pics)

[TreeSurfer]

ok guys, here she is. i installed the new piston and cylinder with fresh gaskets tonight. here is a few pics.

piston and cylinder

muffler and carb installed

finished

 

[nick 55]

Please tell me the bar on that thing extends 2 feet past the end of that pic.

In all honesty, what happened to the saw?

Nick

 

[TreeSurfer]

its a 36" bar

 

[MCW]

Good work. What year is the saw from and does it have an adjustable H jet?
Aftermarket P&C I presume?

 

[husq2100]

having it that far apart, I would have atleast given it a good clean and done the crank seals...new fuel and air filter and carb kit are mandatory for me

 

[TreeSurfer]

has new air filter, fuel filter and carb kit. didnt need new seals. they are fine. the saw is pretty new, only 4 years old so it didnt need new seals. and no its not an adjustable H jet. its the fixed jet. there is a little screw on the carb throttle lever that can adjust how far open the butterfly valve can open basically the same as an H screw but your stuck with the fuel mixture its fixed with.

 

[logger 12345]

has new air filter, fuel filter and carb kit. didnt need new seals. they are fine. the saw is pretty new, only 4 years old so it didnt need new seals. and no its not an adjustable H jet. its the fixed jet. there is a little screw on the carb throttle lever that can adjust how far open the butterfly valve can open basically the same as an H screw but your stuck with the fuel mixture its fixed with.

holy..... only 4years old and it needed rebuild of top end??

regardless if you were sleeping with the saw it wouldn't need a rebuild after just 4years,especially a 3120xp,maybe at the very least
a piston ring change,but each to there own!!

unless something happened it?/?

 

[TreeSurfer]

it was straight gassed. groundie didint tell me and one day it just stopped working. the rings were melted to the piston. the cylinder was badly scored because of the piston so both had to be replaced. ill get some pics later.

 

[Nitroman]

Surfer, you can look back through the forum and see the thread where clear instructions on how to ream the fixed jet just a little larger so you'll get more gas into the saw if you want.

 

[logger 12345]

it was straight gassed. groundie didint tell me and one day it just stopped working. the rings were melted to the piston. the cylinder was badly scored because of the piston so both had to be replaced. ill get some pics later.

aww hard luck,beautifull saw man! i gave my dad a lovely 61 husqvarna for christmas when i bought my new 365special,he forgot to add oil to the mix one day and the lot went,i needed to replace bottom end and top end,i'm amazed your bottom end is ok
i know you probably sound like a lad that may know more than most of us put together,but the main bearing on the crank may look ok but they need very close inspection aswell as the case bearings for damage,my old 61 i rebuilt had little pieces of metal coming out of the main bearing that i spotted under a lot of inspection,your very lucky if it's just a top end that needed doing.

but i guess when you stripped it all down you obviously saw that things were fine down below,imagine when you were cutting now how hot things had to get to melt the top end,at that point what did the bottom bearings suffer....

if it was me for saftey sake i would have replaced the lot,but it's not a 3piece crank is it??
if it is i would have just split the cases and done the worx

 

[TreeSurfer]

naw, bearings were ok and there wasnt any play in the crank shaft. everything checked out fine. although the connecting rod to the piston was blued, but that got replaced along with the needle cage bearing.

 

[husq2100]

How did you change the con rod??? Simon Bertrand in Canada can mod that carb so it has an adjustable high needle.

 

[logger 12345]

How did you change the con rod??? Simon Bertrand in Canada can mod that carb so it has an adjustable high needle.

was going to ask the very same thing about the con rod,thought that crank was not a 3piece ??

 

[mdavlee]

Maybe he meant the wrist pin. The crank is 3 piece and can be pulled apart and put back together with some pressure. I know some racers do this to build strokers.

 

[TreeSurfer]

i meant the connecting wrist pin yes thanks mdavlee.

 

[jropo]

Now I see why you have a 3120 jug to practice porting on. :msp_ohmy:
Did the groundy straight gas the other saws too?

 

[TreeSurfer]

heres the old blown piston

 

[jropo]

Ouch!!
How much did that set you back?

 

[TreeSurfer]

$500 quit

 

[TreeSurfer]

ok, i fired her up. she smoked alot from all the lube in the crank and the cylinder. tuned the low and idle and violla shes a runner! 11,000 rpm. shes good to go.