First Chainsaw Build, Ratty Husky 351 to Ported 346xp

[cuinrearview]

I would also suggest sourcing a carburetor, filter neck, and filter from a 359 or 357xp. Leave the support ring out of the intake boot when you swap it over too. You'll notice a difference.

 

[Rickick91]

I would also suggest sourcing a carburetor, filter neck, and filter from a 359 or 357xp. Leave the support ring out of the intake boot when you swap it over too. You'll notice a difference.

I do already have the neck and filter setup from the 359. I am going to see where i get with the stock HDA 159 before trying one of the bigger carbs off the 359 357xp. ive heard in some cases it makes little gain and can shorten the power band. Thank you for the suggestions.

Does removimg the bronze difusing ring make that much difference?

 

[cuinrearview]

I do already have the neck and filter setup from the 359. I am going to see where i get with the stock HDA 159 before trying one of the bigger carbs off the 359 357xp. ive heard in some cases it makes little gain and can shorten the power band. Thank you for the suggestions.

Does removimg the bronze difusing ring make that much difference?

It hurts nothing, and increases the opening slightly. On the red and orange 346s I've done, pretty much just like yours, I lost a little throttle response with a 199 but picked up power in the cut. For mild modding like that you really don't gain a ton of un-loaded rpm, but that's not what we're after. The bigger intake setup even helped my little 42mm 2147.

 

[Rickick91]

Upon proper measurement you'll see that the original is a 45mm 350/353 cylinder.

Do you have plans for the salmon colored covers? If not I could use them.

I don't have plans for them as of yet, and will let you know if I get tired of sitting on them. I'm really enjoying this build and may use them for another.

 

[Rickick91]

Sorry for the lack of updates,

Been slammed at work and had little energy for the build. Got around to my second muffler mod. attempt this week and it is passable, so I put it on today while I was tinkering, and it looked pretty good. I will sand blast it and paint it later. I opened up the hole about the size of a elongated nickel. If its to big I have some shim stock I can place with the screen to shrink the hole accordingly to tune the size.
Kept going till I had the carb. back to gather and on, and figured Id fire it up.
Forgot to tighten the spark plug so it took a bit to get it going right, and she's a runner! torque is great compared to my other 50cc saw and 42cc saw. I didn't take the time to get the tach out and just did a quick tune by ear. I'm sure its still fat and will tune it properly tomorrow. I did find that the 359 intake didn't fit quite right, and is cocking the whole assembly a bit. I think its the choke and kill switch support pushing on the carb floor. Do any of you mod. the elbow to fit better? ITs making the choke stick a bit.


Here it is all together!

And in the mess with all the others. Really need to clean the shop.

 

[Rickick91]

Had it in the wood today and put the tach on it. Still four stroking to 14,800 rpm. Kinda un-nerving after going online and seeing people saying to tune to 14200. I don't have allot of tuning experience and was wondering if the 14200 was for peak in cut performance and grunt. I also had some trouble getting it to stop from dropping under 2000 after a few full stabs to peak with a pause in between. I had it tuned to 27- 2800 but it would die on the third stab or so like this so I raised the idle. Do ported saw tend to like a faster idle with their higher compression? Muffler sounds good but not to loud, and seems to be getting the heat out as A can place my finders on the top cover above the outlet which is only 1/8" off the top cover, and still feel cool air going by the gap between the cover and the chain brake. I am very excited it is running fantastic! but am scared I may roach my first saw running it at 14,800 rpm. BUt usually 4 stroking is a sign there is more fuel than is being burned causing a rich condition. Right?

-I am running 93 octane pump gas with 46:1 Motul synthetic ester core 800 2T.

Remember the carb is a Walboro 159. I don't know if this is the same as the 346xp NE's ever had, but it seems to supply plenty of fuel I checked and I am at just over half a turn H neddle at 14,800 rpm. At 3/4 turn it is rich as all get-out and around 12,000 rpm. The low is at just over 1 turn I think. Been a long day.

 

[cuinrearview]

People dial them back to make sure it doesn't lean out in long cuts or when it's hot out. Like a little bit of a safety net. It sounds like you're leaning out if it wants to die after working it for a minute. Give it more fuel at idle with your L screw and then adjust the idle speed to 2700.

 

[cuinrearview]

The 159 will fuel a mild build like yours, but the fuel tank vent may not keep up. There are posts here on how to mod it.

 

[Rickick91]

The 159 will fuel a mild build like yours, but the fuel tank vent may not keep up. There are posts here on how to mod it.

Per Mastermind,

I have removed all but the silver disk from my vent and installed it with some sealant as it had fallen out. I did not drill the hole in the bottom behind the vent as he says he found it let fuel leak out and into the intake on the epa vented saws. I didn't want it to leak all over when left in a hot truck bed so I didn't drill it even though it goes to fresh air with no hose. I didn't notice any fuel starvation issues and it went fat with no problems. however I will keep an ear on this.

Thank you for checking as I had skipped over this detail in my post from Sunday night.

Would a lean high side cause the occasional drop past 2000 rpm, and stall after hard stabbs? I know there is no middle circuit in these carbs, and it takes a bit for the low side to catch the rpm and start fueling, but it seems to do it a bit too much. Also Was I on the right track about the higher Compression causing it to want a higher idle speed?

 

[cuinrearview]

Per Mastermind,

I have removed all but the silver disk from my vent and installed it with some sealant as it had fallen out. I did not drill the hole in the bottom behind the vent as he says he found it let fuel leak out and into the intake on the epa vented saws. I didn't want it to leak all over when left in a hot truck bed so I didn't drill it even though it goes to fresh air with no hose. I didn't notice any fuel starvation issues and it went fat with no problems. however I will keep an ear on this.

Thank you for checking as I had skipped over this detail in my post from Sunday night.

Would a lean high side cause the occasional drop past 2000 rpm, and stall after hard stabbs? I know there is no middle circuit in these carbs, and it takes a bit for the low side to catch the rpm and start fueling, but it seems to do it a bit too much. Also Was I on the right track about the higher Compression causing it to want a higher idle speed?

I haven't found this with mild bumps in compression, but each saw is different. You'll just have to find its tune. It's not as much a lean condition at idle in the sense we think of it. It would be more akin to a fuel line getting pinched. You just need to give it more at idle. I've found the balance between hot, cold, loaded, un-loaded difficult to find with the 159. Just keep your screwdriver with you in the woods. You'll find it. Mine have become less finicky as they break in too.

 

[Gypo Logger]

I groove on the 346, I got three, real fast really light saw. Cuts with a vengeance and authority with 3/8.