Building a 290/390

[huskihl]

There are minor differences between an 029 & 290. Kinda like the 044 & 440.

A little more than that. An ms290 is actually the same as an 029 super. Just in case somebody reads this, don't buy an 029 piston for a 290. Not sure why they changed it. 029 is 45mm. 029s and 290 are 46mm. 310 is 47mm. 039/390 are both 49mm.
@MustangMike, nothing at all wrong with them. Keep the chain sharp. An 039 cuts right with an 036. 039 may have the edge on torque

 

[Adirondackstihl]

This is a 290 I built for Phil.

 

[Adirondackstihl]

Did your cylinder come with the piston bearing?

Nope

Piston (w/rings installed)
Wrist pin
Cylinder
Clips (w/ 1 installed)
Impulse barb
Engine pan bolts

 

[94BULLITT]

Nope

Piston (w/rings installed)
Wrist pin
Cylinder
Clips (w/ 1 installed)
Impulse barb
Engine pan bolts

That is stupid. That is how the kit was for my 036. They come in the husky kits and some AM.

 

[huskihl]

Nope

Piston (w/rings installed)
Wrist pin
Cylinder
Clips (w/ 1 installed)
Impulse barb
Engine pan bolts

That stinks a little bit. I've reused most of the ones I've redone. No issues yet, but they don't get used much.

What's your preference: pre installing the bottom pan and let the sealer set up overnight? Or get the pan in the chassis and work everything into place and seal it down then?

 

[TJ the Chainsaw Mechanic]

So I have a 290 with an air leak....What would be the advantage of a 390 piston and cylinder? Not trying to hog the thread, but I am interested for sure.

 

[huskihl]

So I have a 290 with an air leak....What would be the advantage of a 390 piston and cylinder? Not trying to hog the thread, but I am interested for sure.

So I have a 290 with an air leak....What would be the advantage of a 390 piston and cylinder? Not trying to hog the thread, but I am interested for sure.

56cc vs 64cc. Same weight

 

[94BULLITT]

and close to 3/4 hp more

Sent from my SPH-L710 using Tapatalk

 

[fearofpavement]

All the 1127 series saws are essentially the same. The differences as already pointed out are primarily the different cylinder/piston sizes. (all the engine parts are the same other than those)
There are differences in plastics as well as the MS series had a bit different shaped orange plastic than the 0 series did. Either style of plastics will fit either style of saw but you can't mix/match.

Some early MS saws used the same plastics as the 0 series just to make it more confusing.
The MS390 and 039 use the exact same engine, The 029 Super is the exact same engine as the MS290 and so forth...
If you're going to have one of these saws apart, it makes no sense to me to build it up as anything but the largest size 039/MS390 as you'll have more power in the same sized saw. A healthy, muff modded 039 will cut very close to a stock 044.

 

[94BULLITT]

All the 1127 series saws are essentially the same. The differences as already pointed out are primarily the different cylinder/piston sizes. (all the engine parts are the same other than those)
There are differences in plastics as well as the MS series had a bit different shaped orange plastic than the 0 series did. Either style of plastics will fit either style of saw but you can't mix/match.

Some early MS saws used the same plastics as the 0 series just to make it more confusing.
The MS390 and 039 use the exact same engine, The 029 Super is the exact same engine as the MS290 and so forth...
If you're going to have one of these saws apart, it makes no sense to me to build it up as anything but the largest size 039/MS390 as you'll have more power in the same sized saw. A healthy, muff modded 039 will cut very close to a stock 044.

A 029 and MS290 are the same. A 029 super and MS310 are the same.

Sent from my SPH-L710 using Tapatalk

 

[TJ the Chainsaw Mechanic]

56cc vs 64cc. Same weight

Cool! Sounds like a plan!

 

[Lightning Performance]

All the 1127 series saws are essentially the same. The differences as already pointed out are primarily the different cylinder/piston sizes. (all the engine parts are the same other than those)
There are differences in plastics as well as the MS series had a bit different shaped orange plastic than the 0 series did. Either style of plastics will fit either style of saw but you can't mix/match.

Some early MS saws used the same plastics as the 0 series just to make it more confusing.
The MS390 and 039 use the exact same engine, The 029 Super is the exact same engine as the MS290 and so forth...
If you're going to have one of these saws apart, it makes no sense to me to build it up as anything but the largest size 039/MS390 as you'll have more power in the same sized saw. A healthy, muff modded 039 will cut very close to a stock 044.

I'd love to agree with all that but...
The plastics, yes. The 46mm 029 super jugs I've had are way different numbers than anything later. That said, they were not all the same timing numbers from the factory. And yes, it does make that much difference. One jugs a pig and the next one is a screamer. With a muff mods it's way more noticeable. They all have way to much time till blow-down. Basically the transfers are in to late.

I have two 390 AM jugs to check time and try out. I suspect they will be on the conservative side of performance. We can fix that

I built all these test saws.
A 039 oem muff on one particular stock 029 super jug hangs right with a 390 decomp jug up to 25" bar. Granted we did not know what crank was in each one at that time. The ignition timing is different on several 029/290 039/390 cranks I checked some years back. The compression reading was way different. I mean that in all ways. Static, swept and PSI gauge readings. Again, yes, we did use the same gauge, same day, same mix/oil, same break-in time, same cabers, same carb, same same same... The saws had more than ten tanks through both. We swapped carbs. No difference. Some jugs have different combustion chambers and the 45mm jugs are pigs IMO. There is more to the tale to be told. Not that it even matters...
I'll be quit now

 

[Lightning Performance]

I lied

A 029 and MS290 are the same. A 029 super and MS310 are the same.

Sent from my SPH-L710 using Tapatalk

Sorry but, no they are not. I have 029S in 46mm and 310 in 47. I have never seen a 029S in 47mm but, not saying they don't exist.

I had three bone stock unmolested 029S in 46mm. Oh btw that was a good runner in stock form with mods it went very well. 310's are OK. I have one with broke fins to play with sometime.

 

[94BULLITT]

I lied



Sorry but, no they are not. I have 029S in 46mm and 310 in 47. I have never seen a 029S in 47mm but, not saying they don't exist.

I had three bone stock unmolested 029S in 46mm. Oh btw that was a good runner in stock form with mods it went very well. 310's are OK. I have one with broke fins to play with sometime.

I was wrong, you are right. It looks like the 029S has the same bore as the MS290.

 

[Lightning Performance]

So... Can I write this down for future reference. I might be the only time I was ever "right."lol

Next we will find out they did make 47mm in R&D

 

[MustangMike]

Jeremy, are you going to provide details of the build?

Also, why does that piston say "45" on the top, aren't we going to 49?

Another member tells me these thing are not "fun to work on", any advice or comments on that?

 

[Chainsaw Jim]

Buying a replacement bar stud before hand and lubricating all the av rubber makes these things way nicer to work on.
Well, if you don't have the stud removal tool.

 

[Mark71gtx]

I just finished up one of these and I will saw it seemed sluggish to me. Opening up the muffler makes it a completely different saw. If you don't do anything else, open up the muffler on this series!

 

[fearofpavement]

I'd love to agree with all that but...
The plastics, yes. The 46mm 029 super jugs I've had are way different numbers than anything later. That said, they were not all the same timing numbers from the factory. And yes, it does make that much difference. One jugs a pig and the next one is a screamer. With a muff mods it's way more noticeable. They all have way to much time till blow-down. Basically the transfers are in to late.

I have two 390 AM jugs to check time and try out. I suspect they will be on the conservative side of performance. We can fix that

I built all these test saws.
A 039 oem muff on one particular stock 029 super jug hangs right with a 390 decomp jug up to 25" bar. Granted we did not know what crank was in each one at that time. The ignition timing is different on several 029/290 039/390 cranks I checked some years back. The compression reading was way different. I mean that in all ways. Static, swept and PSI gauge readings. Again, yes, we did use the same gauge, same day, same mix/oil, same break-in time, same cabers, same carb, same same same... The saws had more than ten tanks through both. We swapped carbs. No difference. Some jugs have different combustion chambers and the 45mm jugs are pigs IMO. There is more to the tale to be told. Not that it even matters...
I'll be quit now

I'm unclear as to what you are claiming here. Are you saying that there are different part number cranks with the different engines that have varying timing or that there are manufacturing differences in the cranks that result in timing variations?
Same for the cylinders, are you saying the 029S uses a different cylinder than the MS290 or that you found differences between them? All the MS290 cylinders I've had apart say 029 46mm and the MS390's say 039 49mm. And also I've seen MS390's with and without the decomp.

 

[Adirondackstihl]

Jeremy, are you going to provide details of the build?

Also, why does that piston say "45" on the top, aren't we going to 49?

Another member tells me these thing are not "fun to work on", any advice or comments on that?

I'll try to do a step by step. Just started a new job yesterday after 13+ yrs at the old one so I'm a little strung out right now.

No clue why the piston is stamped 45.
It is a 49mm.

About being fun or not......
Well... I don't have a problem with them. Nothing to them actually.




Like mentioned above: I also recommend buying the rear bar stud. Highly unlikely that it'll come out without a fight. This saw here is the first one I didn't have to struggle with, but someone had been in this one prior.

Muffler mod is a must