Stihl 500i fast idle and overheating bar and chain

[user 122190]

The saw starts perfectly, revs fast, awesome power. But after a bit of use it makes an unfamiliar whine, in and out of the cut. When this is occurring the idle is fast. Not excessively fast, but if there were and idle screw I would definitely be dialing it down. I read thru the shop manual, and it is mostly about how to dismantle and reassemble the saw. Not much about how to calibrate it (like with the M-Tronic). Only mention is attaching diagnostic to the saw and following the directions. I might be taking it to the shop and having them hook it up and see if there is something going on. I did pull the plug and it was very dry and of a light tan color. I'm use to seeing a darker shade, so this might be an indicator that the fuel is a bit lean. I was hoping this was a breakin thing, but I feel like I am past breakin, that the saw is fully broken in. There is something going on, but I don't really know for sure.

Any ideas or similar experiences with the 500i?

 

[user 122190]

Looks like I'll be bringing the saw in and have a technician look at it. Gots to get this fixed before something serious happens to it. I called and checked and they do have the MDG 1 Analyzer to do a systems check on it. Fudge!

 

[user 122190]

Just to change things a bit, I put the 24" B&C on the 500i and did some late day cutting on some log lengths. Seems a lot better.

I have been suspicious of the 32" B&C for sometime now. Seems to get quite hot. The oiler is at max and it does consume a tank of oil for a tank of gas, so it seems to be oiling okay. Just because that isn't conclusive I did drill out the oiler holes in the bar yesterday, to no real effect. The 32" B&C are about 6 years old and I use to rarely run it on the 461. Only with the 500i have I started to really use them heavily, so I cannot completely vouch for them.

With the 24 I was able to touch the bar and chain immediately after cutting. Something with the 32 I am not able to do, hence my suspicions are all pointing to the 32s as part or wholly the problem.

I'm going to head out tomorrow morning and will cut a cord of wood with the 24" B&C mounted and try and draw some conclusions to the state of the saw afterwards.

I hate the idea of taking it to a shop. I feel like it costs a hundred just to have them carry the saw to their work table. And then it starts getting expensive.

And I pulled the spark plug after running the 24s, and no real change.

 

[Woodslasher]

I put a 32" bar on my Husky 562 (PLEASE, no comments on that) and it made a dry, whirring sound before too long. To me it looked like the chain was too dry so I'm guessing that's the problem with your saw too. Does the 500i have the whole "knock the pin in to advance it further" deal? I wouldn't take it to a shop without making sure a dry chain isn't the issue. Heck, unless I was a production cutter I wouldn't take my saw to a shop period.

 

[PV Hiker]

My question also @Woodslasher . Has a drift been used to drive in the pin that will allow more oil to the bar?

 

[ValleyForge]

Just to change things a bit, I put the 24" B&C on the 500i and did some late day cutting on some log lengths. Seems a lot better.

I have been suspicious of the 32" B&C for sometime now. Seems to get quite hot. The oiler is at max and it does consume a tank of oil for a tank of gas, so it seems to be oiling okay. Just because that isn't conclusive I did drill out the oiler holes in the bar yesterday, to no real effect. The 32" B&C are about 6 years old and I use to rarely run it on the 461. Only with the 500i have I started to really use them heavily, so I cannot completely vouch for them.

With the 24 I was able to touch the bar and chain immediately after cutting. Something with the 32 I am not able to do, hence my suspicions are all pointing to the 32s as part or wholly the problem.

I'm going to head out tomorrow morning and will cut a cord of wood with the 24" B&C mounted and try and draw some conclusions to the state of the saw afterwards.

I hate the idea of taking it to a shop. I feel like it costs a hundred just to have them carry the saw to their work table. And then it starts getting expensive.

And I pulled the spark plug after running the 24s, and no real change.

Did you clean out the 32” bar groove? You’d be amazed at the crap in it even after a few cuts….

 

[sean donato]

That saw is rated to run a 32" bar. Doesn't mean the oiler puts out enough or it's staying with the chain.

 

[ValleyForge]

That saw is rated to run a 32" bar. Doesn't mean the oiler puts out enough or it's staying with the chain.

A 36” I believe….the oiler can deliver tank to tank when maxed, which is fine. The 36” bar spits oil at the tip when clean, not so much when cruddy, it seems very sensitive to crud on the longer bars…

 

[user 122190]

I have seen this once before. Cutting with a neighbor, his saw got so hot the fuel was boiling. We could not figure it out. Luckily it was a new saw like a week old, if that. He took it back to the dealer, who swapped out the bar and chain, and never had the problem again. I just remembered this, and unfortunately I didn't follow up and learn the cause, or what it was about the bar or the chain, or them together. From what I do recall the dealer did the swap with no real diagnosis. Just did it, like it was a common thing.

This 32 of mine came with the 461, which was used. And as infrequently as I did use it, I do recall it acting funny/odd sometimes. It was brief and I never gave it much thought, cause I rarely rarely used the 32.

I'm anxious go test this theory out tomorrow.

 

[user 122190]

Did you clean out the 32” bar groove? You’d be amazed at the crap in it even after a few cuts….

Always.

 

[user 122190]

That saw is rated to run a 32" bar. Doesn't mean the oiler puts out enough or it's staying with the chain.

It flings oil, and revving it out of the cut it will saturate the chain. At first this was my line of thinking. Not so anymore.

 

[user 122190]

One more thing. As I was swapping the 32 with the 24 I noticed a hot spot on the bar. Not blue, but warn thru the factory coating.

On a good note the chain is nearing its end. If the saw behaves I'll put an Oregon chain on to test the 32" bar.

 

[Woodslasher]

Could be a slight pinch there, which would certainly make some noise.

 

[user 122190]

I put a 32" bar on my Husky 562 (PLEASE, no comments on that) and it made a dry, whirring sound before too long. To me it looked like the chain was too dry so I'm guessing that's the problem with your saw too. Does the 500i have the whole "knock the pin in to advance it further" deal? I wouldn't take it to a shop without making sure a dry chain isn't the issue. Heck, unless I was a production cutter I wouldn't take my saw to a shop period.

Yeah, the pin is punched in. Oiler is at max.

 

[user 122190]

Could be a slight pinch there, which would certainly make some noise.

Yes very possible. I'll run feeler gauges the length of the bar and pay extra attention at that spot.

 

[user 122190]

I have been thinking about it, the fast idle. What I came up with is the saws sensors are trying to cool the saw down. Faster idle, more air flow across the cylinder fins. Very interesting if true.

I'll inspect the bar today to the best of my abilities. Actual cutting will have to wait, as I have to many other things to do today.

 

[DND 9000]

I believe that is very unlikely. Richening the mixture would have a stronger cooling effect for the internal engine parts as the air from the flywheel.

 

[user 122190]

I believe that is very unlikely. Richening the mixture would have a stronger cooling effect for the internal engine parts as the air from the flywheel.

I suppose. Maybe both. I don't know.

 

[ericm979]

How well does the chain turn by hand? I have had bars that were very slightly too narrow in the groove, so that when the chain was properly tight it had more friction than usual and was harder to turn by hand. That can generate a lot of heat.

 

[user 122190]

How well does the chain turn by hand? I have had bars that were very slightly too narrow in the groove, so that when the chain was properly tight it had more friction than usual and was harder to turn by hand. That can generate a lot of heat.

Chain moves very smooth in the goove. I didn't test its resistance when hot. I expect it to be more difficult.

I spent a good amount of time with the feeler guages and could find nothing wrong. Bar and chain both look good.

Making jerky and welding were today's priorities. Probably this weekend I'll get out and test the saw with the 24" B&C off the 400c. No problems with the 400c, so I can feel positive that if it is the saw or the 32" set I'll know. Damn frustrating, but at least I have the surplus equipment to fully test all this out, before resorting to the dealer and his diagnostic equipment.