440 bigbore 52mm, or 54mm?

[Greenclimber]

I know I can go with a 440 bb from 50mm to 52mm. Is it possible to swap out a 460 jug and cylinder bb kit? 54mm is what I saw on e-bay "STIHL CHAINSAW 046 MS460 PISTON / CYLINDER NEW BIG BORE ( 54MM ) NIKASIL"

Will this fit on the bottom end of the 440, and also fit everywhere else, plastics and such.

Thanks!

 

[Adamgaspo]

I think a lot of builders have installed an 046/460 p/c on the 440/044 but there are modifications that need to be performed and that's about all I know. you'll have to wait for mm or Snelling to chime in on this.

 

[Greenclimber]

The 440 just by itself is a great saw. I've been using it for milling here and there, and It's starting to get weak. I looked at the piston and cylinder the other day, and it's starting to get some scoring.

 

[Greenclimber]

Lastly, I don't know what to go with. There are so many on e-bay, and all with different prices. From super cheap like $38 & free shipping, on up to $175. What's the difference?

 

[funky sawman]

My opinion on the matter is pick up a oem 046/ ms460 cylinder and use that insead of a far lesser quality aftermarket jug. But what do I know, I'm just a underpaid overworked full time saw mechanic.

 

[Bieber]

Don't know if its possible with a 460 big bore 54mm but a oem p/c will give a feelable power increase though you have to make some modifications:

http://www.arboristsite.com/community/threads/440-460-hybrid-finished.266634/#post-5037552

 

[funky sawman]

Ohh, with the oem jug use a meteor piston. Try to find a later build date piston so it has the higher quality circlips and piston pin that is lightweight like the oem style

 

[HuskStihl]

Just clean up the cylinder and put in a new meteor piston and rings. You'll almost certainly get more power from that than an aftermarket big bore kit

 

[funky sawman]

I am familiar with the older meteor kits, the ones with the crappy circlips and pins. I got a 272 meteor piston last week, the newer ones, it had nice circlips, and was top quality. Changed my mind on what I thought about meteor pistons

 

[wcorey]

If the bb cyl fits an 046 and the oem 046 cyl can be tweeked to fit an 044, then it would seem that the bb cyl would also work on an 044 with similar tweeks.

That said, bb kits in general have a reputation of having negligible performance gain over standard sized bore.
One reason for this, I think, is that most cylinders seem to have the transfer 'bulges' placed close to the physical limits of where they will fit into the saw chassis. almost brushing the flywheel on one side and the clutch case on the other, sometimes with a built in flat spot/depression for clearance already.
When that same externally maxed out cylinder design is bored out a couple millimeters, the transfer gets shallower by the same, decreasing the volume and also decreasing the angle the charge enters the cylinder, compromising the scavenging.
So what is gained in displacement is lost in the less efficient transfer geometry, that can't easily be regained even with porting.

 

[pioneerguy600]

The case volume in a 044 or MS440 is too small to run much more than a stock OEM 046 cylinder and piston. To get the most from that swap a good bit of port work is needed to compensate for the reduced case volume. The OEM o46 cylinder will need to have some shaving done to it to clear the flywheel and on some, the sides of the base need shaving to fit down onto the crankcase base. Putting a BB 046 cylinder on a 044 would be possible with enough modifications but it would never make good power unless it had plenty of port work done to it, the OEM 046 would make more power than any BB kit ever could on a stock 044 chassis.

 

[jsmith40004]

Yes it will fit with some clearancing. I built one with a hyway kit. Definatly have to bridge the transfers and finger port to get enough transfer.

This kit also free ported into the exhaust.

I remember years ago Timberwolf measured the crankcase volume of both an 044 and 046. It was 3cc difference

James

 

[Greenclimber]

Thanks for all of the suggestions. I want to keep it as simple as possible. Sounds like keeping my cylinder and just putting in a meteor piston is the way to go: http://www.ebay.com/itm/METEOR-BRAN...070?pt=LH_DefaultDomain_0&hash=item35df1afefe


I just wanted to point out that my cylinder has scoring. I don't feel like that will be able to get cleaned up at all. If I need to go with replacing everything should I go with: http://www.ebay.com/itm/150593570757?_trksid=p2060778.m1438.l2649&ssPageName=STRK:MEBIDX:IT

Lastly I saw this bb NWP: http://www.ebay.com/itm/381050145335?_trksid=p2060778.m1438.l2649&ssPageName=STRK:MEBIDX:IT

If you have a direct link of something entirely different let me know, and I'll just go with that.

 

[Adamgaspo]

You would be better off ordering parts from a reputable forum sponsor. They have the parts you need and none of the crap that goes along with fleabay.
Stick with a meteor piston.
Reuse the piston pin clips, the am clips are mostly junk.
If there is transfer on the cylinder use some hydrochloric acid that you can get from a hardware store to clean the cylinder walls.
Thats about all I have without getting really in depth.

Others will chime in to help you with your decisions and other options.

And lastly were you able to determine the reason the saw was not running correctly?
I'd hate for you to spend money on fixing the saw and not find the cause of the problem first.

 

[pioneerguy600]

HL pistons and cylinders have been good for me and are sold by one of our sponsors, send him a PM and get a price before going to eBay, he will stand behind his sale, watsonr

http://www.arboristsite.com/community/threads/hl-supply-pistons.224067/

 

[Greenclimber]

You would be better off ordering parts from a reputable forum sponsor. They have the parts you need and none of the crap that goes along with fleabay.
And lastly were you able to determine the reason the saw was not running correctly?
I'd hate for you to spend money on fixing the saw and not find the cause of the problem first.

Good point.
Actually no, I'm not sure why the saw isn't working. It still has compression. I took it to a Stihl shop, over in Pittsboro, NC and they looked it over. The guy spayed some kind of break cleaner around while the saw was halfway running saying he was looking for vacuum leaks. They said that it might be a vacuum leak, crank shaft seals, or something like that. They suggested tightening down the head bolts. (which I did) We looked at the cylinder together, and could see scoring from when it had run hot, but they said that if felt like it still had a good amount of compression. Just couldn't get it running. and stay running except on full choke. I'll go through the carbs again in the next day or so. I have been using the saw as a mill, and figured I just burned it up. I though I'd tear the whole thing down, and rebuild it. I'm pretty slow right now with my own jobs.

I noticed that you are located in Charlotte, NC. I'm heading to Charlottesville, VA for my arborist certification course on the 9th-11th of December with Bill Murray. I'll be driving through Charlotte, NC on the 4th or 5th of December to meet with the Patrick Franklin (Special Assistant to the President) over at Bartlett Tree Exports. I'll have the saw with me if you want to geek out for a bit after I'm done. If you're running your own business I contract climb, and carry my own insurance. I've got plenty of references up and down the East-coast, and in the Midwest. When I'm done with my meeting at Bartlett we can meet up and do a rec-climb, or get something to eat if you're not busy. I've never been to Charlotte and don't know my way around at all.

 

[nmurph]

Let's see some pics of the inside of your cylinder. It doesn't sound like it couldn't be cleaned up and re-used.

 

[Greenclimber]

Great idea, I'll see if I can get some good pictures for you. I might even go ahead and tear it down. That way I can inspect the bottom end for "play"

 

[Greenclimber]

So I took off the muffler and got some pictures. Then I took out the spark plug and tried my best to get a good photo, but just couldn't get one at that angel. I decided to check the carbs to see if that's the reason the saw wasn't working. I don't expect it to be the case because I just cleaned them about 3 tank fulls ago...

Guess what... Clogged screen. So does that mean it's time to replace filter and fuel-line? Could that screen get clogged from a very dirty air filter? I don't see how a dirty air filter would affect the screen. However I don't really know how 100% how carbs work.

Hows the piston and cylinder looking? About 50%?
It's past midnight, and I haven't tried starting up the saw yet, but I will in the morning, and then I'll check back in to give everyone a heads up on how things worked out.


Any ideas?

 

[AKDoug]

That sucker is scored and needs to come apart. They can lean seize like that from the clogged screen in your carb. This saw would get a complete tear down and rebuild if it was in my shop. I would NOT mess around with any big bore kit. You probably will be able to clean up the cylinder and get a Meteor piston to run in it. I would replace both crank seals and carefully inspect the intake boot and impulse line.