Need more power from a ms290

[brownstown]

Let me start out by saying I don't have a clue what I'm doing here. So I built a ms290 outta spare parts and pieces I had laying around so the saw isn't necessarily important to me so if we tear it up no big deal. I put a ms390 piston and cylinder on it, ported the muffler and I'm thinking about putting a ms460 carb on it just ti see how much more power I can get compared to a stock ms290. Does anyone have any advice or tips I could try to get it as close to a hot saw as I can? Would a base gasket delete be a good idea or not worth trying? Any advice would be appreciated.

 

[singinwoodwackr]

Ok, so…you like Frankinsaws, right? LOL
just keeping this thread going…might get interesting

so, the 390 top end fit ok? No issues with cycling?
will the 460 carb bolt up ok?

in general…you have a “home” type saw, not a pro type so there won’t be much out there on this kind of drastic modding.

if it were mine…muffler mod, advance the timing a tad and that’s it.
but…anyone else?

 

[thompsoncustom]

so if we tear it up no big deal

Well then....do everything listed above plus port it and raise the compression by brazing in the combustion chamber.

 

[singinwoodwackr]

Dead thread...withdrawn...

 

[brownstown]

Ok, so…you like Frankinsaws, right? LOL
just keeping this thread going…might get interesting

so, the 390 top end fit ok? No issues with cycling?
will the 460 carb bolt up ok?

in general…you have a “home” type saw, not a pro type so there won’t be much out there on this kind of drastic modding.

if it were mine…muffler mod, advance the timing a tad and that’s it.
but…anyone else?

No cycling issues what so ever. It was running pretty rich so I opened the muffler up a little more because I couldn't get it to tune right. But now it seems to be running great.

 

[singinwoodwackr]

Pics? Video?

 

[a. palmer jr.]

When I do those I usually just put a piston/cylinder on it, along with a muffler mod. You can use a larger carburetor if you like but there's no such thing as a cylinder gasket delete on these saws, just a bit of Dirko on the bottom pan to seal it up. Just remember to use new crank seals and get the pan sealed good and it should run okay.

 

[thompsoncustom]

last time I swapped a 390 top end on a 290 I ran a pop up since its a clamshell and could use the compression. if I had to do it again I would just braze the combustion chamber like I recently did on a wild thing.

the stock 290 muffler is horribly restrictive I would open it up to match the bore size (100%) or better yet cut the muffler apart and gut it and braze a deflector on the side. I hate the muffler on that saw.

the 460 carb might bolt up but either way doesn't look like it would take much to make it work. I ran a 460 carb on my ms260. is the venturi bigger on the 460 carb vs the 290? also not much point in swapping it if you haven't ported it yet.

 

[Captain Bruce]

When I do those I usually just put a piston/cylinder on it, along with a muffler mod. You can use a larger carburetor if you like but there's no such thing as a cylinder gasket delete on these saws, just a bit of Dirko on the bottom pan to seal it up. Just remember to use new crank seals and get the pan sealed good and it should run okay.

DITTO

 

[user 122190]

Get a Magnum sticker. I usually get 14.7% power increase. A Super Magnum sticker gets a lot more power.

https://www.arboristsite.com/threads/first-mod-to-the-500i.357880/

 

[nixon]

Not really a way to increase the power output of the saw . But , run a narrow kerf .325 chain/bar combo . I can’t directly site a source . But , I’ve read that they require 10-14% less power to run over a standard .325 . I’ve done it on 029/390 conversions and 350/346 conversions . Works very well .

 

[Jed1124]

It’s been a long time but I think the 390 uses a larger Venturi in the carb than the 290 and 310

 

[a. palmer jr.]

I didn't mention it earlier but I usually don't try to advance the ignition any. They are usually hard enough to pull without that.

 

[brownstown]

With the 460 carb and decent muffler port the saw runs like a scalded dog, it's a tad much but I'll make a video soon and upload it for y'all soon.