Project Stumpbroke 3120xp

[Stumpys Customs]

Not as big of a beast but I wonder how a 2100 would stack up against this thing?

Now that's a question I might be able to answer in a week or so.

 

[Hedgerow]

I really just wanna run that thing!
Having the carb adjustable is gonna be priceless...

 

[jerrycmorrow]

no problem on taking the screw out. unnerstand.
i got some saws with fixed H. some look like they have bosses and could be drilled. wondering what are the specifics regarding drilling and tapping. is it just a standard carbon screw? what angle did you grind the end of the screw? i'm guessing you kinda matched the angle on the L screw? any problems removing drilling debris from the passages? anything else to consider?

 

[nstueve]

not to take any credit at all, but I did tell doug he needs to do all his saws! lol... These saws are going to rock come summer! Is there a long bar shoot out at hedgefest? Wish I woulda known that... :msp_mellow:

Can't wait to run these monsters, any of the 4 of them will be fun to run!

 

[tlandrum]

no problem on taking the screw out. unnerstand.
i got some saws with fixed H. some look like they have bosses and could be drilled. wondering what are the specifics regarding drilling and tapping. is it just a standard carbon screw? what angle did you grind the end of the screw? i'm guessing you kinda matched the angle on the L screw? any problems removing drilling debris from the passages? anything else to consider?

just tapping the predrilled boss on the carb and adding a needle does not make the carb fully adjustable. all it does is allow you to add more fuel to the high side than the fixed jet allows. to make a 3120 carb fully adjustable you must make a new main nozzle for it,block off the fixed jet,re route the fuel to the new high side needle and reroute the fuel to the low side needle. i have a 3120 here now that just has a needle added and it does nothing but make the saw 4 stroke unless under a massive load. stumpy you should show a pic of how its made fully adjustable so people will understand the process better.

 

[Stumpys Customs]

no problem on taking the screw out. unnerstand.
i got some saws with fixed H. some look like they have bosses and could be drilled. wondering what are the specifics regarding drilling and tapping. is it just a standard carbon screw? what angle did you grind the end of the screw? i'm guessing you kinda matched the angle on the L screw? any problems removing drilling debris from the passages? anything else to consider?

All basic stuff, carbon screw, taper is at whatever degree, remove welchplugs & main nozzle to keep things clean.

not to take any credit at all, but I did tell doug he needs to do all his saws! lol... These saws are going to rock come summer! Is there a long bar shoot out at hedgefest? Wish I woulda known that... :msp_mellow:

Can't wait to run these monsters, any of the 4 of them will be fun to run!

Thanks, I owe you a big hug......... :msp_thumbup:

 

[Stumpys Customs]

just tapping the predrilled boss on the carb and adding a needle does not make the carb fully adjustable. all it does is allow you to add more fuel to the high side than the fixed jet allows. to make a 3120 carb fully adjustable you must make a new main nozzle for it,block off the fixed jet,re route the fuel to the new high side needle and reroute the fuel to the low side needle. i have a 3120 here now that just has a needle added and it does nothing but make the saw 4 stroke unless under a massive load. stumpy you should show a pic of how its made fully adjustable so people will understand the process better.

Main jet is plugged and it will lean out to past 14K, which should be lean enough. This isn't a thread on how to make the 3120 carb adjustable, but I might do a thread on down the road about that. This is just a thread to show what I've been up to.

 

[cat-face timber]

Stumpy I hate you even more now...

All I need is another BIG HUSKY....
BUT DAMMIT!

Going to Laughlin soon, might win enough to buy one...


Your work, as always looks amazing..

 

[Adam Smith]

Stumpy, When I seen your pics and video you got a standing ovation from me. Top notch and great job. I was looking at your pics and it shows your craftsmanship with your port work and attention to detail super great. Also it think its awesome the way that you are free to tell anyone your secerets that you have spent countless hours and money to figure out. I come from a automotive racing background that when you ask someone a question about a set up or a trick they just look at you like you kicked there favorite huntin dog. Hats off

 

[Stumpys Customs]

Stumpy, When I seen your pics and video you got a standing ovation from me. Top notch and great job. I was looking at your pics and it shows your craftsmanship with your port work and attention to detail super great. Also it think its awesome the way that you are free to tell anyone your secerets that you have spent countless hours and money to figure out. I come from a automotive racing background that when you ask someone a question about a set up or a trick they just look at you like you kicked there favorite huntin dog. Hats off

Thanks. I do keep a few things tucked away in my back pocket.

 

[nstueve]

Thanks, I owe you a big hug......... :msp_thumbup:

what??? no kiss with that hug! :msp_ohmy:


and honestly I have to give credit to doug for sending the brand new 3120 down... I figured he'd wait till the warranty was up! Kudos to Stumpy on some great builds and to doug for supplying the awesome saws!

 

[Stumpys Customs]

what??? no kiss with that hug! :msp_ohmy:


and honestly I have to give credit to doug for sending the brand new 3120 down... I figured he'd wait till the warranty was up! Kudos to Stumpy on some great builds and to doug for supplying the awesome saws!

Yep, Doug has been a pleasure to work with.

 

[pdqdl]

Interesting...Why did Husqy ruin the saws to begin with?

I have a 1996 3120 and it has no electronic limiter in the coil and the carb came with high and low adjustment needles from the factory. It sounds rather similar to your upgraded version.

I cannot imagine that these changes were done to make it more reliable, safer, or to save money on warranty issues. After all, this one has made it for over 16 years.

 

[Stumpys Customs]

Interesting...Why did Husqy ruin the saws to begin with?

I have a 1996 3120 and it has no electronic limiter in the coil and the carb came with high and low adjustment needles from the factory. It sounds rather similar to your upgraded version.

I cannot imagine that these changes were done to make it more reliable, safer, or to save money on warranty issues. After all, this one has made it for over 16 years.

I have no idea why they did it.

 

[LegDeLimber]

Appreciate your answers here.

Realized my brain cramp on the machining set ups.
wasn't thinking in terms of an arbor for the base cut.
Still thinking like I've got a removable head cylinder (the motorcycle days)
set up in a large 4-jaw, to bore the i.d. and a light skim of the base
to keep things squared.

 

[JRHAWK9]

Interesting...Why did Husqy ruin the saws to begin with?

I have a 1996 3120 and it has no electronic limiter in the coil and the carb came with high and low adjustment needles from the factory. It sounds rather similar to your upgraded version.

I cannot imagine that these changes were done to make it more reliable, safer, or to save money on warranty issues. After all, this one has made it for over 16 years.

since when does the EPA mandate things with reliability as a concern. It can be argued it's actually quite the opposite. All they care about is what exits the exhaust in ppm's....if it happens to shorten the lifespan of the saw, o well.

 

[Stumpys Customs]

Appreciate your answers here.

Realized my brain cramp on the machining set ups.
wasn't thinking in terms of an arbor for the base cut.
Still thinking like I've got a removable head cylinder (the motorcycle days)
set up in a large 4-jaw, to bore the i.d. and a light skim of the base
to keep things squared.

Don't worry, I have them moments about every 60 seconds.:msp_ohmy:

 

[johnfawn2000]

395 or 3120

yes they are very disappointing stock.
Yes i done the carb myself.



I'll sign your saws at the gtg:rolleyes2:
I'd rather not pull the screw out right now. I cut a shoulder & tapered the end. Nothing real fancy.

stumpys,which has the most to gain the 3120 or 395 new in box,to do your magic.thanks my income tax refund come in and this is some she money.money she dont kno about thanks

 

[torinocobra]

Interesting...Why did Husqy ruin the saws to begin with?

I have a 1996 3120 and it has no electronic limiter in the coil and the carb came with high and low adjustment needles from the factory. It sounds rather similar to your upgraded version.

I cannot imagine that these changes were done to make it more reliable, safer, or to save money on warranty issues. After all, this one has made it for over 16 years.

Please, please, PLEASE post photos of the factory H needle showing how the air filter base and air filter are notched around it!

 

[Stumpys Customs]

stumpys,which has the most to gain the 3120 or 395 new in box,to do your magic.thanks my income tax refund come in and this is some she money.money she dont kno about thanks

About the same. I would personally have more use for a 395, but a 3120 would be sweet.