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

[EvilRoySlade]

I know some of the FI dirt bikes have been having trouble with fuel filters and plugging of injectors. I’d be curious what pressure the tank is at for the injection to work.

 

[Spladle160]

Ok, oil thread with relation to how it affect injection vs carburetion. What I'm suggesting is it seems like an injection engine may be more effective at vaporizing fuel/oil meaning you could potentially run a richer mix or the same mix with a thicker oil. I've never seen an over lubricated bottom end. I have seen fouled plugs and recognize the potential for lowering the octane in your fuel and getting pre detonation.

Viscosity hinders atomization and does not necessarily increase the oils load carrying ability. For example:

Bel-Ray H1-R viscosity 12.4 @ 100ºC, 141 @ 40ºC, viscosity index 72

High viscosity makes it thick and hard to atomize, low viscosity index means the viscosity and load carrying ability quickly dissipate with increased temperature.

Bel-Ray SL-2 8.1 viscosity @ 100ºC, 41 @ 40ºC, viscosity index 176

low viscosity makes it thinner and easier to atomize, high viscosity index means the viscosity and load carrying more slowly dissipate with increased temperature.

MOTUL 800 2T Road Racing viscosity 19.2 @ 100ºC, 157.4 @ 40ºC, viscosity index 140

crazy high viscosity makes it thick as mud and very difficult atomize at high mix ratios, relatively high viscosity index means the viscosity and load carrying more slowly dissipate with increased temperature.

I would never consider running MOTUL 800 2T in a carbureted saw, particularly a smaller one, at high mix ratios even though I'm sure it would give fantastic protection.

But here's the takeaway of the long winded OMG not another oil thread post.

I would be interested in seeing a MS500i run MOTUL 800 2T because it may be able to efficiently atomize it and provide greater lubrication.

 

[StephK87]

thanks for the detailed explanation!

One thing I keep hearing about the 500i is that the saw is really thirsty compared to the 461 or 661, I'm curious how these claims turn out after my testing.

 

[Spladle160]

Golly, that should be interesting. I would have guessed it would be more fuel efficient but I suppose we shall see. I did read some marketing spin about not comparing fuel per time but fuel per work accomplished. Probably means they know it's thirsty!

 

[usmcbuckwild]

Ok, oil thread with relation to how it affect injection vs carburetion. What I'm suggesting is it seems like an injection engine may be more effective at vaporizing fuel/oil meaning you could potentially run a richer mix or the same mix with a thicker oil. I've never seen an over lubricated bottom end. I have seen fouled plugs and recognize the potential for lowering the octane in your fuel and getting pre detonation.

Viscosity hinders atomization and does not necessarily increase the oils load carrying ability. For example:

Bel-Ray H1-R viscosity 12.4 @ 100ºC, 141 @ 40ºC, viscosity index 72

High viscosity makes it thick and hard to atomize, low viscosity index means the viscosity and load carrying ability quickly dissipate with increased temperature.

Bel-Ray SL-2 8.1 viscosity @ 100ºC, 41 @ 40ºC, viscosity index 176

low viscosity makes it thinner and easier to atomize, high viscosity index means the viscosity and load carrying more slowly dissipate with increased temperature.

MOTUL 800 2T Road Racing viscosity 19.2 @ 100ºC, 157.4 @ 40ºC, viscosity index 140

crazy high viscosity makes it thick as mud and very difficult atomize at high mix ratios, relatively high viscosity index means the viscosity and load carrying more slowly dissipate with increased temperature.

I would never consider running MOTUL 800 2T in a carbureted saw, particularly a smaller one, at high mix ratios even though I'm sure it would give fantastic protection.

But here's the takeaway of the long winded OMG not another oil thread post.

I would be interested in seeing a MS500i run MOTUL 800 2T because it may be able to efficiently atomize it and provide greater lubrication.

I concur wholeheartedly on all points made here. With one caveat: the injector in the saw. We need to know the specs of the injector (metering valve/metering seal size, pre-filter screening) as we know the Stihl injector is internally regulated at 2.5 psi fuel pressure. All measurements need to be based on the 2.5 psi through whatever the size/length of the metering seat is.

I assume that in an electronically controlled injector that is internally regulating is going to be rather sensitive to viscosity changes. I know they show it starts perfectly in sub-zero temperatures, but when we start tossing different oils at it, will it still?

 

[MG porting]

Oil thread.

No good no.

 

[MG porting]

Like all other current saw's in their line up, Stihl recommends a mixture of 50:1

View attachment 176256

A big point is also, here in germany (i think some other european countries too) you have to use premixed 50:1 alkylate fuel (Aspen, Motomix) for commercial use by law.

As far as the function of the injection is concerned, on closer examination you can see that it is not rocket science. The injector just sprays fuel in the intake. So it is not directly injected to crankcase like i thougt before.

View attachment 176257

View attachment 176258

After the weekend, I will disassemble the saw to see it exactly

Just like a car so that way the air charge gets a chance to mix with the fuel better that's how I see it anyways.

 

[huskyboy]

I would like to know if they decided to keep the 6202 on the flywheel side/6203 size on pto like a 461... or if it’s running two 6203 sized bearings.

 

[BK13]

A big point is also, here in germany (i think some other european countries too) you have to use premixed 50:1 alkylate fuel (Aspen, Motomix) for commercial use by law.

So, not having ever been to Germany, let alone on commercial logging operations, is this something there is any possibility of being checked, or is this another law that will never be enforced?

 

[Spladle160]

as we know the Stihl injector is internally regulated at 2.5 psi fuel pressure.

Well, actually we don't all know. And knowing that now sort of makes me re-assess my thoughts. 2.5 PSI is nothing. Not sure you can create some magic atomizing spray pattern with that. Don't know why I assumed it was somehow working with a ~45psi injection. I'm kind of sad now.

 

[usmcbuckwild]

Well, actually we don't all know. And knowing that now sort of makes me re-assess my thoughts. 2.5 PSI is nothing. Not sure you can create some magic atomizing spray pattern with that. Don't know why I assumed it was somehow working with a ~45psi injection. I'm kind of sad now.

I read the 2.5psi in a thread on AS, where someone broke down an TS500i that had a bad injector and then broke down the injector.

https://www.arboristsite.com/community/threads/so-i-took-a-stihl-ts500i-injector-apart.307486/

 

[Spladle160]

hmm. How long until one of our hop up masters finds a heavier spring to slip into the check valves so we're working with as much pressure as the pump will put out. Of course the pump probably wouldn't handle the additional pressure the spray pattern would be terrible. Only one way to find out for sure though...

 

[usmcbuckwild]

hmm. How long until one of our hop up masters finds a heavier spring to slip into the check valves so we're working with as much pressure as the pump will put out. Of course the pump probably wouldn't handle the additional pressure the spray pattern would be terrible. Only one way to find out for sure though...

Most likely the injector and electromagnetic tension plate with the injector seat seal on it is sized specifically for the application (the injector nozzle). But, drilling out the injector nozzle to allow MORE fuel through it utilizing the same size seat seal may be a possibility. I wonder if that is a 1 off design injector or if it has other applications. If there are other applications, swapping a larger injector may be possible.

 

[RI Chevy]

Saw isn't even out yet but we got the issues solved already. LMAO [emoji16]

 

[Dub11]

thanks for the detailed explanation!

One thing I keep hearing about the 500i is that the saw is really thirsty compared to the 461 or 661, I'm curious how these claims turn out after my testing.

If its thirsty from hauling ass then thats all right by me.

Most likely the injector and electromagnetic tension plate with the injector seat seal on it is sized specifically for the application (the injector nozzle). But, drilling out the injector nozzle to allow MORE fuel through it utilizing the same size seat seal may be a possibility. I wonder if that is a 1 off design injector or if it has other applications. If there are other applications, swapping a larger injector may be possible.

I was just think if you are gonna do a race saw alky application my swipe the set up off the concrete saw that has the injector in the case and add it to the the existing set up.

 

[Cobby08]

Like all other current saw's in their line up, Stihl recommends a mixture of 50:1

View attachment 176256

A big point is also, here in germany (i think some other european countries too) you have to use premixed 50:1 alkylate fuel (Aspen, Motomix) for commercial use by law.

As far as the function of the injection is concerned, on closer examination you can see that it is not rocket science. The injector just sprays fuel in the intake. So it is not directly injected to crankcase like i thougt before.

View attachment 176257

View attachment 176258

After the weekend, I will disassemble the saw to see it exactly

I was told they wanted to make it so tank was able to be removed in less than 3 minutes because of the bear it was to access the injector on the TS units. Sounds like they want serviceability to be an improvement across the spectrum with the recent changes in the FS/KM/BR units as well as the new saws.

 

[Intoxsawcated]

I was told they wanted to make it so tank was able to be removed in less than 3 minutes because of the bear it was to access the injector on the TS units. Sounds like they want serviceability to be an improvement across the spectrum with the recent changes in the FS/KM/BR units as well as the new saws.

I didn't know the Germans could engineer anything that could be taken apart in less than 3 minutes.

Sent from my SM-S327VL using Tapatalk

 

[Cobby08]

I didn't know the Germans could engineer anything that could be taken apart in less than 3 minutes. And then be reassembled in similar time.

Sent from my SM-S327VL using Tapatalk

Fixed...

 

[nohoff]

Bearings with 15x37,7x11 mm on both sides

 

[DND 9000]

Bearings with 15x37,7x11 mm on both sides

I thought the bearing on the

flywheel side is 15x37,7x11mm and on the
clutch side it is 15x37,7x13mm?