Project Stumpbroke MS290

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Stumpys Customs

Stumpbroke
Joined
Jan 16, 2010
Messages
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Location
south central MO
A local customer of mine brought me a Ms 290 to modify. Not sure what kind of gains to expect out of it, but figured it's worth a try.

This thread is not a step by step rebuild thread. If I can find a link I'll post it. I beleive THall has a thread on how to rebuild one of these.

Just gonna post some picks of my work.

Pic of the motor in my vise with the degree wheel.
<a href="http://s772.photobucket.com/albums/yy4/stump7997/?action=view&amp;current=saws015-1.jpg" target="_blank"><img src="http://i772.photobucket.com/albums/yy4/stump7997/saws015-1.jpg" border="0" alt="Photobucket"></a>

Here's the numbers
Ex Dur-158*
Trans Dur-120*
In Dur-158*
Blowdown-19*

I've also got some timed cuts made before I tore it down. I'll post them later once I git the after times down, and report the results.
 
Last edited:
http://arboristsite.com/chainsaw/133453.htm
I think this is the link to The rebuild.

Some pics of the ports before.
Intake
<a href="http://s772.photobucket.com/albums/yy4/stump7997/?action=view&amp;current=saws017-1.jpg" target="_blank"><img src="http://i772.photobucket.com/albums/yy4/stump7997/saws017-1.jpg" border="0" alt="Photobucket"></a>

Exhuast
<a href="http://s772.photobucket.com/albums/yy4/stump7997/?action=view&amp;current=saws024.jpg" target="_blank"><img src="http://i772.photobucket.com/albums/yy4/stump7997/saws024.jpg" border="0" alt="Photobucket"></a>
 
After pics of the ports (sorry I didn't take any pics of the outside ports before)

Inktake
<a href="http://s772.photobucket.com/albums/yy4/stump7997/?action=view&amp;current=saws031.jpg" target="_blank"><img src="http://i772.photobucket.com/albums/yy4/stump7997/saws031.jpg" border="0" alt="Photobucket"></a>
<a href="http://s772.photobucket.com/albums/yy4/stump7997/?action=view&amp;current=saws029.jpg" target="_blank"><img src="http://i772.photobucket.com/albums/yy4/stump7997/saws029.jpg" border="0" alt="Photobucket"></a>

Exhuast

<a href="http://s772.photobucket.com/albums/yy4/stump7997/?action=view&amp;current=saws030-1.jpg" target="_blank"><img src="http://i772.photobucket.com/albums/yy4/stump7997/saws030-1.jpg" border="0" alt="Photobucket"></a>
<a href="http://s772.photobucket.com/albums/yy4/stump7997/?action=view&amp;current=saws028.jpg" target="_blank"><img src="http://i772.photobucket.com/albums/yy4/stump7997/saws028.jpg" border="0" alt="Photobucket"></a>
 
You can see I couldn't do much with the uppr transfers. The ring spaceing kept me from doin any more. I guess I could move the locator pins, but don't think it would be worth the effort.

I've got more work to do on it. Thinkin of welding up a small popup to improve the comp. Also got to gut the muffler & make it breath.
 
You can see I couldn't do much with the uppr transfers. The ring spaceing kept me from doin any more. I guess I could move the locator pins, but don't think it would be worth the effort.

I've got more work to do on it. Thinkin of welding up a small popup to improve the comp. Also got to gut the muffler & make it breath.

Interested to see the gains... You bout ready to experiment on a 028? Oh, and the 460? Stihl lookin'... Sorry buddy...:msp_confused:
 
Bring it on, No prob on the 460. Maybee I'll port my dad's Husky 460 & beat them all:msp_ohmy:

You know? I even lowered myself to calling the local saw shop and asking if they had any damaged or shelled 460's, and they acted like that just "never" happens!!! :msp_angry:
Psshhh... I'll bet they got a pile of them things in the back... You know there are hundreds of them things committing hary kary all over the ozarks...
:beat_shot:
 
I'm still trying to find you a shelled 460 as well, my cousin thinks he has one, he had to go out of town for the weekend to a wedding. I guess I'm just going to have to load up and go over and see what he has for sure. He was positive he had two or three 044/440's and two thrashed 660's and one thrashed 066. I just got to convince him he needs to part with some of his junk.

The work on the 290 looks great. I've got to get that 133 over to you, so we can show that young whipper snapping 7900 who it's daddy is.
 
WOW I didn't think there was that much to remove out of those clamshells. I think I need to start reading and figure this porting stuff out. Those numbers don't mean anything to me so I need to do some reading here.

Great work on the ports.
 
I new we would convert you to running real saws. The addiction will get stronger as you test this saw and before you know it you will own a MS460:hmm3grin2orange:

Nice work:msp_thumbup:
 
I'll have to admit I made a mistake. I read the degree wheel wrong on the ex port. I read 99* it was actually 101*. guess I read the wrong side of the 100* mark. I caught the mistake checking the timing after porting. I lowered the intake to give me a lil more dur to catch it up to the exuast (the first wrong reading). Not sure if I'm gonna raise the ex or not. Sorry fer the mixup. Here's the stock & modded timing #'s

Stock
Ex dur- 158*
Trans dur- 120*
In dur- 158*
blowdown- 19*

Modded
Ex dur- 158*
Trans dur- 120*
In dur- 166*
blowdown-19*
 

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