Another 290-390 build thread Dukes Top End Cross PopUp

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Natehimself36

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Howdy fellas, my name is Natehimself and this is my 390 build. This is also my first real post so it might take me 105 tries to get posting down right.

I picked a non running stihl ms290 (2012) from a junk yard a while back with plans to rebuild it and I’m just now getting to it. Saw had a pretty yucky p/c so I ordered a “Dukes Premium Nikasil” 390 p/c and a cross pop up. I plan to clean up / widen ports, advance timing a little, carb & muffler then send it all the way.

Here are the original p&c 0E43C4BA-A81D-488B-903F-2148D27F201C.jpegCAE52E85-FD40-4F81-B643-2CDB56E6D9EC.jpeg02C6EC93-5253-4066-A2D8-6C7B4BB18E32.jpeg788B7519-2D77-412A-A8E5-4F39262D2F94.jpeg65B7FB6B-6DD9-4A44-BC1B-E4E3A42C334C.jpegF6F25E0A-1E04-42FD-9D2B-985F94E53089.jpeg

Here is a couple of the patient. She’s in good spirits. I told her I’d have her clam split and a piston inside in no time. Eagerly waiting.
7AF6288C-B0F7-4630-9481-CAF310A5457A.jpeg22786417-CEDA-44C8-9E86-3140A44573C6.jpeg
I’ve got the new p/c but no pics yet. Will upload more tomorrow. I threw some engine primer on the cyl. Before I took any pictures. I haven’t cleaned the cast up or ported yet. I’m looking forward to seeing what you guys think of the Duke’s premium nikasil cyl. Dukes on here isn’t he?
More tomorrow!
 
I've had no complaints with the Dukes pistons or cylinders I've used. I have no idea if they stand up well, but they go together and run well.
 
I love the fact that you're bringing this saw back to life. I'll always have room on my shelf for my 290.
With that being said, what's your end game here financially? it sounded like you were going to resell this after the rebuild? You're already starting off good because you have a free saw (I assume being from the junkyard). What's the rebuild kit cost? $75? After an air filter, carb kit, gas lines, any who knows, you could be in it for $100-$125. Locally, ms290s are listed for $200-$300 and sounds like typically being sold in the $250 range. Is someone going to give you $350 for a frankensaw non-oem p/c ms290/390? Maybe.
I guess the reason I'm here posting is because i'm trying to figure out a way to make money on these 1125 saws as well (I can't find free ones and blow up ones still bring $100 around here for whatever reason). And it can't hardly be done unless they're free and even then it's hard to double your money.
Regardless, you're in it now so ya gotta finish! Good luck with the rebuild and remember, we all like pictures!
 
I love the fact that you're bringing this saw back to life. I'll always have room on my shelf for my 290.
With that being said, what's your end game here financially? it sounded like you were going to resell this after the rebuild? You're already starting off good because you have a free saw (I assume being from the junkyard). What's the rebuild kit cost? $75? After an air filter, carb kit, gas lines, any who knows, you could be in it for $100-$125. Locally, ms290s are listed for $200-$300 and sounds like typically being sold in the $250 range. Is someone going to give you $350 for a frankensaw non-oem p/c ms290/390? Maybe.
I guess the reason I'm here posting is because i'm trying to figure out a way to make money on these 1125 saws as well (I can't find free ones and blow up ones still bring $100 around here for whatever reason). And it can't hardly be done unless they're free and even then it's hard to double your money.
Regardless, you're in it now so ya gotta finish! Good luck with the rebuild and remember, we all like pictures!
I’ve made $20-30 each on the 2 rebuilds I’ve done. It’s a good thing I enjoy doing it.
 
I've rebuilt about 50-60 saws in the last 12 months ,and the only way I can make any money is if the saw is free and I use aftermarket parts. For a saw that I really want and is more desirable ( Husky xl's for me) I'll go more money. Bars and chains are very pricey so powerhead only saws if they are bottom end just go into the parts bin. I just do it to learn more about saws....the money is in flipping lawn tractors.
 
Sometimes they are really ugly to start with. Here's an MS310 before I rebuilt it to a 390:
Stihl MS310 Before.jpg
It runs fine today and looks like a chain saw once again. I also added an outside bumper spike. Two dealers refused to mess with it. It took me about 12 hours.
 
I am keeping this saw for myself and using it to learn how to work on a saw, particularly clamshells. Not looking to make any money on it. I’ve been looking for a larger saw (70cc+), non running, to rebuild and keep for me but I saw this guy and bought it. I did pay a little for it but not much. Scrap yard so they charge scrap price at least.

Here’s some pics of the pop up and cyl. Should’ve taken some before I sprayed it but whatever. What do you guys think about the transfers? The casting seems ok. I don’t have any experience with buying things like this so I have nothing to go off of.
One thing I will say is a guy could cut a finger clean off where the seals go. Sharp as a knife. E915AE5B-47FD-445D-9140-C9244AB800CF.jpeg75CBB48C-9335-45DA-A241-73B1410ECCE2.jpeg86151FDD-7FDB-4601-9287-7EBE6BC0B7F3.jpeg4B49192B-9830-47AD-8168-8600184F3018.jpeg540512A3-23EB-400C-9359-363E2BAD744A.jpeg4E9F90DD-5E00-42ED-B38B-EE3E5DEBFA7C.jpeg84340F95-A0B3-49B4-B549-913C508A00E3.jpeg7D9D7F69-459D-4124-A1BC-9EB70CA7F301.jpeg26C9C811-11AD-4A3B-A1D3-CE2B3F25A273.jpeg96798AF3-454E-46EE-9BBA-2D7CDC2C1E0F.jpeg
 
I really don’t like how thin they are. Much, much less material . Thin enough that it’s a very sharp edge. Is this normal or defective you guys think? Should I build it up with anything or just go for it?

compared to mahle 290 cyl 3C5A4215-B60A-4292-84DC-A9DA18CDC4C4.jpeg0478D6E7-1BF9-434C-B220-57FC47E140A3.jpeg
 
If you're building it for yourself, Then this is a great investment imo. You know what you have, and take pride every time you make chips.
I like rebuilding saws for a part time hobby. And if I don't make money on a saw, it just means i don't get to buy a bigger, nicer, prosaw for rebuild next. (hence my questions above).
I don't know enough about the transfers and porting to be of any service to you unfortunately.
Good luck. don't forget to record your first startup.
 
If you're building it for yourself, Then this is a great investment imo. You know what you have, and take pride every time you make chips.
I like rebuilding saws for a part time hobby. And if I don't make money on a saw, it just means i don't get to buy a bigger, nicer, prosaw for rebuild next. (hence my questions above).
I don't know enough about the transfers and porting to be of any service to you unfortunately.
Good luck. don't forget to record your first startup.
That’s exactly how I feel about it. I enjoy mechanicing and I’ll have the saw a long time.
 
This the same project I am working on.
Mine is an 029 that I bought about 10 years ago and is still running fine. I only cut about 12-15 ricks of firewood per year using a 20" bar. Always trees that have been uprooted or taken down by others. The last couple years I've been getting into 30" + trees, so I thought I'd like to have a little more oomph.
I started doing my due diligence and started looking for parts. The term nicosil was new to me and when I read that Porche was using it in the 70's, I figured it was good enough for me. So I got the 49mm from Duke off of ebay but not with the pop up.
Mine has the same issue with the thin walls for the seal seat and the transfers are also very sharp. The seal seat is actually so thin it was showing daylight at the bottom 1/8" or so.
I ground on the edges with a 1/4 ball grinding wheel just a enough to break the edges and around the ports. The seal seat I ground the very bottom till I had at least about 1/16" of meat left. There is still plenty left to support the seal so hopefully I didn't screw it up.
Something else I noticed were the ring gaps were really tight, 0.003". A few swipes with an India oilstone and I'm now at 0.006". If that's incorrect, please let me know.
Right now I'm waiting on the mailman. I got to thinking, I may as well buy a new crank and pan. Then it'll just be an engine swap and I don't have to mess with a good running engine and I can just put the old one on the shelf. It only cost me an extra 30.00 or so than a complete assemble engine would have cost me. I'm kinda stupid that way.....
Anyways, I'm real curious to see what the difference is with the larger engine.
 
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