Need Help, 500i issues

[Shanesaw80]

Hey guys I’m hoping someone can give me some insight into what may be happening.

I have a friend of mine who is working in northern Ontario at the moment, extremely cold weather and the trees are loaded with snow. They have 6 500i’s on the program and none are running at the moment. 5 of them have less then 10 tanks of gas through them.

Basically what he’s telling me is that they won’t start and are flooding themselves, everyone of them. At first he thought maybe they were all frozen but he had them in a heated building for a day and they still won’t run. Take out the plug, extremely wet, dry it off and put it back in. A couple pulls and it will fire but die immediately and then just completely flood itself again. He’s tried everything that he can’t think of but nothing has worked and I have very little experience with these saws.

And before anyone mentions getting it diagnosed he’s 12hrs from the closest dealer. Any help on what could be the potential cause would be great. Thanks!!

 

[Stump Shot]

I'm no 500i expert by any stretch of the imagination, but a couple things come to mind.
One, try and start and run it at full wide open throttle and see if it will run long enough to tune itself right again.
Two, find the place that controls the fuel entering the injector and give it a light tap with a screwdriver handle or some such thing(non destructive like) and see if it gets unstuck.
As all I can comprehend is it's either being told to give too much fuel for some unknown reason, or it's a mechanical failure of the injector controller as in dirt, frost etc. keeping it stuck open.
Good luck with your diagnosis and hopefully someone with more direct details will come along to help.

 

[Czed]

That much money in equipment
I'd stack them up in front of the dealer
And demand they be fixed.

 

[Sawdust Man]

We better all run right out and buy one of these amazing 500i saws.....

 

[huskyboy]

Did he try dumping the fuel mix out in the saws and trying new fresh fuel mix?

 

[huskihl]

I’ve heard of a couple other Canadian guys having problems when it got cold. The fuel filter iced up from water in the fuel. New fuel and filter and he was good to go. That could be the same problem with yours and now that they’re inside in the heat the sensor is making it really rich

 

[farminkarman]

I’ve heard of a couple other Canadian guys having problems when it got cold. The fuel filter iced up from water in the fuel. New fuel and filter and he was good to go. That could be the same problem with yours and now that they’re inside in the heat the sensor is making it really rich

This sure sounds like a plausible explanation.

 

[Shanesaw80]

It could possibly be a fuel issues but something specific to the 500i. I text him what Huskihl had written so he’s going to swap out the filter and see if it helps. He did just say that they are running the same fuel and mix in a 461, 462 and a 372 and all 3 are running fine. They are only having issues with the 500’s.

 

[Canadian farm boy]

It could possibly be a fuel issues but something specific to the 500i. I text him what Huskihl had written so he’s going to swap out the filter and see if it helps. He did just say that they are running the same fuel and mix in a 461, 462 and a 372 and all 3 are running fine. They are only having issues with the 500’s.

How old is the fuel and what’s the mix oil and ratio? Summer fuel doesn’t always work very good in the extreme cold.

 

[Shanesaw80]

How old is the fuel and what’s the mix oil and ratio? Summer fuel doesn’t always work very good in the extreme cold.

The gas would be what they got from the camp so as for age I have no idea. My buddy Adam runs a Amsoil Saber at 40:1 and his 461 runs fine but not the 500i. As for the other guys I have no idea what they would be running for oil or ratio but I would assume 50:1. Like I said I’m not up there, just trying to help the guy diagnose the problem.

 

[Canadian farm boy]

The gas would be what they got from the camp so as for age I have no idea. My buddy Adam runs a Amsoil Saber at 40:1 and his 461 runs fine but not the 500i. As for the other guys I have no idea what they would be running for oil or ratio but I would assume 50:1. Like I said I’m not up there, just trying to help the guy diagnose the problem.

I hope he gets it figured out. I can only imagine his frustration with $10k worth of saws sitting and not out working like they should be.

 

[Funky sawman]

I have heard of issues just like this also locally. Only in Sub zero weather though. Once warm, they run fine. I will stick with my heavy slow carb saws, that run in any weather.
The one 500i locall that did this, the dealer couldn't reproduce the issue, even using the customers fuel.

 

[lehman live edge slab]

The gas would be what they got from the camp so as for age I have no idea. My buddy Adam runs a Amsoil Saber at 40:1 and his 461 runs fine but not the 500i. As for the other guys I have no idea what they would be running for oil or ratio but I would assume 50:1. Like I said I’m not up there, just trying to help the guy diagnose the problem.

These 500’s are all stock I’m assuming? I talked to my friend at Stihl and he’s looking into it so hopefully have some ideas for him next couple days.

 

[lehman live edge slab]

These 500’s are all stock I’m assuming? I talked to my friend at Stihl and he’s looking into it so hopefully have some ideas for him next couple days.

Was also told you can’t clear a flooded 500i by holding throttle open and pulling, they go into limp mode and won’t start.

 

[Infinitejest]

Haven't had any issues in the montana winter with the three I've had, but whichever is my primary saw gets a new fuel filter once a month religiously.

I haven't run a 500 at colder than -10 F though...the rigging crew can get F'd at that point. And I can stay home and chase the wife around the woodstove.

 

[Stevetheboatguy]

Was also told you can’t clear a flooded 500i by holding throttle open and pulling, they go into limp mode and won’t start.

Quickest way to start a flooded fuel injected two cycle I have found. If possible disable the fuel pump. Give it a squirt of two cycle oil down the plug hole and give er hell. They will usually pop right off.

The op's problem sounds more in depth than a simple flooding like we are used to. Almost reminds me of the tbi go's that would flood themselves when the temp sensor went whacky.......

Hope we get a update on what the problem was once they get it straightened out.

Steven

 

[Hinerman]

@tree monkey

 

[Shanesaw80]

My buddy is in contact with the stihl tech manager for Atlantic Canada. They’re trying to get to the bottom of the problem so when they figure it out I’ll post what happened. It’s been pretty cold up there, usually below -30°C but all the other saws are working fine.

 

[Wolverine]

@dall what say you?

 

[Stevetheboatguy]

My buddy is in contact with the stihl tech manager for Atlantic Canada. They’re trying to get to the bottom of the problem so when they figure it out I’ll post what happened. It’s been pretty cold up there, usually below -30°C but all the other saws are working fine.

This is just food for thought. The fuel they are using is more than likely winter blend. The winter blend has a element of I believe butane or something like it. When it is stored cold it is less prone to evaporate/boil off. But when it it stored at room temperature...... It will disappear from the formula and now you have fuel with much less pop.

I always noticed how the snowmobiles that sat outside day and night. Always ran crisp and clean. The one's that spent the overnight inside. Well they usually seemed off until mid day. Usually when we topped off the fuel........

So..... It may be a fuel and environment issue. The injection can't adjust properly possibly.

Can try a can of true fuel or moto mix to rule it out for good.

Just spitballn.


Steven