Vevor 58cc Chainsaw fettling

[GRW]

Just FYI..... probably relevant to any budget chainsaw (& for all I know, quality ones)...

My Vevor Chainsaw. I've run it in & used it (to run it in & get familiar with it) cutting Firewood for my daughter. It's always been a bit of a faff to start, you could smell it flooding quite easily, & it was a bit smokey & seemed not to be "crisp" like a 2T motor should sort of 4-stroking.
So, I did the Internet thing for info, got the "Pacman" tool to adjust the carburettor & I've gone and tuned it earlier on, (& sharpened the chain).
I think the saw is sent out running way too rich possibly to "play safe". I had to adjust it more than expected & I'd seen online to set it as per the procedure, which is daft as it makes the saw underperform.
Once fettled, it was maybe not "transformed" but certainly much, much better. Not smoky & smelly, I could lower the tickover considerably, & throttle response was much crisper, with the motor sounding much happier. Performance cutting also improved - it felt like a much better machine all round, & I dare say fuel consumption will be better too.
I've yet to see what cold starting is like, nor done a plug check - buy it sounds "right" so I think it'll be OK.

 

[Turbo]

Not sure what those Chinese saws are like regarding the exhaust but I recently did a 'muffler mod' on a Stihl MS290 and it has transformed it.

I did a direct test on the same log and it was as fast as a MS391, its younger and more powerful cousin!

 

[reb78]

Not sure what those Chinese saws are like regarding the exhaust but I recently did a 'muffler mod' on a Stihl MS290 and it has transformed it.

I did a direct test on the same log and it was as fast as a MS391, its younger and more powerful cousin!

What was the mod? My 044 is a beast but happy to make it more of one.

 

[Turbo]

What was the mod? My 044 is a beast but happy to make it more of one.

Plenty of videos online plus posts on the forestry and arb forums. Just search google for muffler mod.

Basically you drill some extra holes to bypass the exhaust internal baffle. It does make them a bit louder but honestly I didn't notice much difference.
It will rev out a lot higher, maybe 1000rpm more. You need to retune it to stop it going too lean. It will also use more fuel.
A pro saw like an 044 should handle the extra rpm better.

 

[mtt.tr]

If you can get it to idle on the low end and for it to cleanly rev up on pulling the Tigger.

And at the top end out of a cut it it's 4 stroking the you'll be golden
If it doesn't 4 stroke it probably running lean on the high end

 

[Memmeddu]

Plenty of videos online plus posts on the forestry and arb forums. Just search google for muffler mod.

Basically you drill some extra holes to bypass the exhaust internal baffle. It does make them a bit louder but honestly I didn't notice much difference.
It will rev out a lot higher, maybe 1000rpm more. You need to retune it to stop it going too lean. It will also use more fuel.
A pro saw like an 044 should handle the extra rpm better.

I've did something similar to my jonsered.
I've enlarged both internal baffle holes and exhaust outlet on the muffler.
I've eventually raised the exhaust port little bit too, but seriously nothing extreme.
It improved a lot.
I have an 025 to play with I may open up this exhaust too
Surely not on my Ms 361 as the thing no matter how much fuel you give her it will always run over 14000 RPM and cut out the spark

 

[GRW]

If you can get it to idle on the low end and for it to cleanly rev up on pulling the Tigger.

And at the top end out of a cut it it's 4 stroking the you'll be golden
If it doesn't 4 stroke it probably running lean on the high end

This last was the info I gleaned from my research (that the saw should "4-stroke" at full throttle under no-load, but run crisply under load).
I'm a near total novice with a chainsaw (& a total novice with chainsaw tuning) so I have erred perhaps very slightly on the cautious side - and I should after running it for a while do a plug electrode check to see it's not running too lean to confirm), but the saw does sound & feel like it's "about right" & feels like it might actually be pretty decent.
For under £80 (though the file that comes with it is useless, & you need to buy a Pacman tool to tune it) with a 20" Bar & 58cc engine - now its "tweaked" I'm rather impressed so far (from a position of ignorance / inexperience admittedly).
I don't think I'll play with the exhaust though, not least because the saw is plenty loud enough already.

 

[Memmeddu]

I don't think I'll play with the exhaust though, not least because the saw is plenty loud enough already.

Not enough yet

The loader and gasoline smelling a chainsaw is the better.
Now seriously once you get high enough RPMs on the rich side of things all the noise are just horsepowers leaving the stables.
Have you any links of your saw?

 

[GRW]

Not enough yet

The loader and gasoline smelling a chainsaw is the better.
Now seriously once you get high enough RPMs on the rich side of things all the noise are just horsepowers leaving the stables.
Have you any links of your saw?

Yes, the 4-stroking at high rpms is "horsepower leaving the stables" but it is also a naturally occurring Rev-Limiter to protect the motor from both over-rev & running too lean, so this is why I see the setup advice being given.

The UK Vevor link I got my saw from is below
VEVOR 58CC 20" Gasoline Chainsaw Gas Powered Wood Cutting Engine Gas Chain Saw | VEVOR UK https://share.google/r4vp1tfHdXzM2QFIa

 

[Memmeddu]

Yes, the 4-stroking at high rpms is "horsepower leaving the stables" but it is also a naturally occurring Rev-Limiter to protect the motor from both over-rev & running too lean, so this is why I see the setup advice being given.

The UK Vevor link I got my saw from is below
VEVOR 58CC 20" Gasoline Chainsaw Gas Powered Wood Cutting Engine Gas Chain Saw | VEVOR UK https://share.google/r4vp1tfHdXzM2QFIa

It should have 52mm bore and 35mm stroke I think you might push it over a shy 13500 RPMs

 

[GRW]

It should have 52mm bore and 35mm stroke I think you might push it over a shy 13500 RPMs

Wow, 13500? The manual states 12000 rpm limit (though again that's to protect the Brand reputation with a comfortable margin of safety I'd expect).
I don't have a tachometer to measure & set a rev limit. I have raised the high rpm screw setting a bit after tuning the carburettor settings, but I've not pushed my luck.

The saw was bought really for one main job - to cut down a (not very big) Ash which is suffering from die-back disease - so it won't see a lot of hard use at all - I just felt it is safer if it is running well and sharp.
The Ash is in the hedgerow alongside the road (not very, very busy, but far from quiet) - and a much larger Ash alongside prevents felling it into the field... so I'll have to lop off branches in manageable manual handling sections into the roadsideverge so they can be cleared straight away one at a time, then cut the trunk down a short section at a time.
I've never cut down a tree before, so I'll be taking every precaution & care to take my time & doing it in small pieces.