Inside the.....? (solved, MS 500i)

[nohoff]

I just stretched the spring a bit. And increased the pressure to 112 mbar.
The pump looks just like a carb. The pressure part is regulated by a spring on the needle side diaphragm. The spring is on the side where on regular carbs the atmospheric pressure presses on the diaphragm. Just open the 4 screws and you can work at the spring. After that put pressure on the tank side of the pump and use a gauge on the injector side of the pump to read pressure and check.

Only thing i got is hot start issues and some smoke.

 

[usmcbuckwild]

I just stretched the spring a bit. And increased the pressure to 112 mbar.
The pump looks just like a carb. The pressure part is regulated by a spring on the needle side diaphragm. The spring is on the side where on regular carbs the atmospheric pressure presses on the diaphragm. Just open the 4 screws and you can work at the spring. After that put pressure on the tank side of the pump and use a gauge on the injector side of the pump to read pressure and check.

Only thing i got is hot start issues and some smoke.

Awesome!

Did you notice any discernible difference in power or is this a precursor for future mods? Is the rest of the saw stock? Muffler mod?

 

[nohoff]

No mods so far.
I only did reversible mods as this was a saw owned by Stihl and we had it only for 2 weeks.
No gain in power as the saw is limited by the air not by fuel.
I noticed the SDS said that it changed the fuel adjustment to the lean side.

 

[Marshy]

I just stretched the spring a bit. And increased the pressure to 112 mbar.
The pump looks just like a carb. The pressure part is regulated by a spring on the needle side diaphragm. The spring is on the side where on regular carbs the atmospheric pressure presses on the diaphragm. Just open the 4 screws and you can work at the spring. After that put pressure on the tank side of the pump and use a gauge on the injector side of the pump to read pressure and check.

Only thing i got is hot start issues and some smoke.

Did you measure the pressure before the "adjustment"?

 

[nohoff]

before it was 100 mbar

 

[ferris]

So the saw realize that it becomes more fuel and makes it leaner

 

[CR888]

As much as I'd like a 500i (I mean who wouldn't?), you would think being 10years more current than a 681 Solo it would give it a pounding. I know its not broken in and the 681 is & modded but... Well I'm keeping my 681 work saw and BNIB one I stashed, in my heart they're still King of the 5-cube. But who knows, some porting and break-in can make a huge difference. Great comparison video Stephen, it ticked all the boxes! ALL your saws ran good.

 

[StephK87]

Maybe, the 681 is the most underrated saw ever just my two cent's

 

[Iceboy]

Maybe, the 681 is the most underrated saw ever just my two cent's

That's what I think aswell.

Στάλθηκε από το SM-A920F μου χρησιμοποιώντας Tapatalk

 

[Dub11]

As much as I'd like a 500i (I mean who wouldn't?), you would think being 10years more current than a 681 Solo it would give it a pounding. I know its not broken in and the 681 is & modded but... Well I'm keeping my 681 work saw and BNIB one I stashed, in my heart they're still King of the 5-cube. But who knows, some porting and break-in can make a huge difference. Great comparison video Stephen, it ticked all the boxes! ALL your saws ran good.

The FI is for hugging trees not slaying them. I know its far fetched but a plugging in tunner would be sweet for these.

 

[CR888]

FI or Carb...I'm not too fussed, but the MSRP of some of these new stihl saws is a bit ridiculous IMO. I think until the price comes down a bit it will hurt sales. I mean we're saw junkies & will buy what we want whether it makes sense or not but for the industry pro's in business buying a tool fit for purpose with value in mind it doesn't make a lot of sense. Stihl is either gouging on price (cause they can & like making money) or their trying too re-coupe R&D costs associated with the tech. The saw production cost would be similar to other saws. I think they should spread out the costs over a longer period & get as many of these saws in the hands of users as possible. Smart money would purchase 2x7900's or 2x390xp's for similar money to 1x500i! And being Aussie I'm used to Stihl charging like a wounded bull. The saw will be over $2-K when on the shelves here.

 

[MG porting]

FI or Carb...I'm not too fussed, but the MSRP of some of these new stihl saws is a bit ridiculous IMO. I think until the price comes down a bit it will hurt sales. I mean we're saw junkies & will buy what we want whether it makes sense or not but for the industry pro's in business buying a tool fit for purpose with value in mind it doesn't make a lot of sense. Stihl is either gouging on price (cause they can & like making money) or their trying too re-coupe R&D costs associated with the tech. The saw production cost would be similar to other saws. I think they should spread out the costs over a longer period & get as many of these saws in the hands of users as possible. Smart money would purchase 2x7900's or 2x390xp's for similar money to 1x500i! And being Aussie I'm used to Stihl charging like a wounded bull. The saw will be over $2-K when on the shelves here.

I think there money hungry they have just in the past two months raised there princess on parts to put it in perspective they raised the he price for a now piston and cylinder for the ms440 $70 more flipping outrageous.

 

[Nutball]

So with the fuel just being injected into the air stream, we can focus on boring the intake or charging it (more if needed) with little worry about vacuum to suck fuel, or work the fuel pump.

Right??

 

[RI Chevy]

Maybe we could add a fuel injection unit to our current traditional carbed saws for more fuel?

 

[nohoff]

you need the vacuum in the crankcase to have impulse for the fuel pump

 

[StephK87]

hey guy's, i have some pictures of the 500i stripped down, but i'm already shocked about the fate of the notre dame of paris..... this need's some moments... it's not only a french monument, it's a monument to our god, europe and humanity..... @CapitaineHaddoc my thoughts are with the french, also my current girlfriend is half french (my grand-grand mother was from Nice too).... i'll keep you updated tomorrow, pictures and numbers of the 500i will follow

 

[Dub11]

hey guy's, i have some pictures of the 500i stripped down, but i'm already shocked about the fate of the notre dame of paris..... this need's some moments... it's not only a french monument, it's a monument to our god, europe and humanity..... @CapitaineHaddoc my thoughts are with the french, also my current girlfriend is half french (my grand-grand mother was from Nice too).... i'll keep you updated tomorrow, pictures and numbers of the 500i will follow

I've seen some of the pics, truly heartbreaking.

 

[TreeLife]

hey guy's, i have some pictures of the 500i stripped down, but i'm already shocked about the fate of the notre dame of paris..... this need's some moments... it's not only a french monument, it's a monument to our god, europe and humanity..... @CapitaineHaddoc my thoughts are with the french, also my current girlfriend is half french (my grand-grand mother was from Nice too).... i'll keep you updated tomorrow, pictures and numbers of the 500i will follow

My mothers family has relatives in Paris, they called us today. Heart breaking to lose such a beautiful, historically significant structure...its horrible.

 

[TreeLife]

Also Steph...you are a super cool cat for bringing all this information and videos to the table. Always humble and kind to this community, thank you for the things you do for us! @StephK87

 

[Marshy]

So with the fuel just being injected into the air stream, we can focus on boring the intake or charging it (more if needed) with little worry about vacuum to suck fuel, or work the fuel pump.

Right??

The injector itself resembles more like an open/close solenoid actuator to allow a metered amount of fuel to enter the intake. It does not look like an automotive fuel injector that atomizes the fuel but the only thing I have to base that on is the animation and the pressure reported by @hohoff. If that's the case then the turbulant flow through the intake will be a vital piece to maintaining proper fuel atomization. Hogging out the intake could do more damage than good because it will reduce intake velocity.