Vermeer SC292 bogs down when head engaged BUT...

[CDTS447]

only about 50% of the time. The rpms will drop and the motor sounds like it's trying to sort a bad idle. This can also be caused if I take an ambitious bite or sweep on an angle in to the stump. High idle doesn't recover until I've either disengaged the head and rolled the dice again on restarting or sometimes I can get lucky by idling down and quickly yoking the throttle full idle.

Some background on this machine:
Machine is 4 years old. 340 hours. Probably spent a little time outside but not much if the fresh looking paint is any indication (no rust). Fresh oil, filters, teeth (not that they matter here I don't think). 29hp Kohler motor, ECH749 if I recall correctly.
I bought it site unseen (big mistake, never again). I bought a running machine... at the dealer (video confirmation) but when I accepted the delivery there was noise coming from the front cylinder. Removed the head and there was debris from some...thing? Still to this day can't figure out what it was because all the head components appeared to be intact. Guides, cups etc. See photos of the debris, cylinder and inside the head for condition. After reassembly, new plugs and a few (3-4) small to medium test stumps, the machine appeared to run fine but the first job it was brought out to I began experiencing the bog. Trust me, bogging down then stalling because the cutter head slows and grabs the edge of the stump 12 inches from the top of a retaining wall is an experience not soon forgotten...

Plugs have been pulled and appear normal according to the charts I normally use to make such determinations. Not rich or lean. Neither is damaged. Belt tension seems good but I don't have a manual to make that claim definitively. I'm not certain this is a motor issue. Possibly clutch gap? Running out of ideas before this gets expensive...

 

[TheAMMIXman]

Is it by chance auto sleeep ahem sweep engaging?

 

[CDTS447]

I'll be honest, this is my first vermeer grinder so I can't even really tell. It's there a way to check?

 

[TheAMMIXman]

Well if it were a 252 I know you can just pull a fuse and it’s disabled. It’s basically for rental yards so inexperienced operators can’t tear up the machine as easy. Slows you down though once you know how to grind efficiently.

On a 252 upgrade thread post #14 this guy plsycamp really spells out how it operates.
https://www.arboristsite.com/community/threads/list-of-upgrades-to-vermeer-sc252.61193/
Maybe it’s similar on a 292?

Hope some of this is helpful.

 

[CDTS447]

Pulling the fuse on a 292 disables the cutter head entirely. No issues with the intake manifold gasket leaking utilizing the carb-cleaner leak test.

 

[TheAMMIXman]

Pulling the fuse on a 292 disables the cutter head entirely.

Very likely true. However, also true on a 252. How do I know?? First fuse I pulled was the wrong one, it also disengaged the cutter wheel on my machine.

Not saying it IS the same on a 292, but it could be. So far your experience sounds very similar to mine with autosleep. I left mine on on purpose on the first few jobs I did when I bought the machine. When I was sick of getting slowed down, and figured I knew the machines limits I then found the correct fuse on the second try. First try it acted just like yours, no wheel engagement. Wrong fuse for me.

 

[iowagold]

those chunks could be piston..
what does the compression and leak down tests look like??
also check the carbs for parts missing...

question
are the chunks magnetic like steel??? or aluminum??
that might give you a tip off where they are from..

almost looks like a washer that got chewed up like from the air filter??

 

[CDTS447]

So with the 292, there is no fuse that is in line with the auto "sleep" (at least not on my machine that I can tell), BUT there is is a connector that leads directly in to the autosweep mechanism just in front of the battery that can be unplugged. After disconnecting, I was able to start and run the machine/cutterhead with no problem. The lack of training wheels took a second to get used to but I'm happy to report I could not recreate the WOT-machine-wanting-to-s**t-the-bed condition that I referenced in my earlier post. Will report back after a couple jobs. Thank you @TheAMMIXman and @Plyscamp for your patient education. Photo of the connector location attached for reference for anyone with a similar issue or that's wanting to neuter the autosweep on a 292.

 

[TheAMMIXman]

So with the 292, there is no fuse that is in line with the auto "sleep" (at least not on my machine that I can tell), BUT there is is a connector that leads directly in to the autosweep mechanism just in front of the battery that can be unplugged. After disconnecting, I was able to start and run the machine/cutterhead with no problem. The lack of training wheels took a second to get used to but I'm happy to report I could not recreate the WOT-machine-wanting-to-s**t-the-bed condition that I referenced in my earlier post. Will report back after a couple jobs. Thank you @TheAMMIXman and @Plyscamp for your patient education. Photo of the connector location attached for reference for anyone with a similar issue or that's wanting to neuter the autosweep on a 292.View attachment 834899

Nice man! So glad you got it figured out. I had a feeling auto sleep might be slowing you down.

Yes it’s faster, be carefull with your new found grind speed. Effective yes, also jams up easier of course, at least on my 252. Always be ready to back off the swing speed lever and or pull the lift lever.

Not sure how much a 292 would benifit but the 252 really woke up after these three mods: No auto sleep, smaller hydro pulley(bringing my swing speed up and my travel speed to the stump), and green teeth.

Yes, green teeth you have to sharpen later and flip and change on the job(if you build the jig and make weights the sharpening isn’t bad, I consider it part of my end of day or weekend maintenance routine). My stock wheel only takes 6 teeth so it’s a quick flip or switch. For me it’s well worth the effort to have sharp teeth ALL day EVERY day. Don’t think sharp teeth matter so much on an 85hp diesel, but I see a big difference using only 27.

Hope the machine stays right for ya

 

[TheAMMIXman]

Just wanted to add:

I was wrong about the fuse disabling “auto-sweep” on 252s. It’s the same as 292s and likely others. I was told it was a fuse on 252s tried that, cutter wheel didn’t come on. Eventually someone informed me otherwise, I think on here, and I must have forgot. It was some time ago, I’ve had this machine a few years now.

Sorry for the misinformation @CDTS447.

 

[CDTS447]

Welp. First stump removal job that lasted more than 15 minutes and the machine started doing it again. Something I have noticed that I do recall in the past is that battery needed jumping before I started grinding. I'm wondering if the EFI motor's finnecky-ness about voltage plays a part so I've had the battery tested. Batteries+ says it's good but a bit low on voltage. This is probably due to it being dead to start with and only running for a few minutes before I got fed up with it. Spending the night on a trickle charger and will report back with whether or not it works. Long shot but here's hoping.

Side note. The machine is "lojacked." I'm guessing the gps tracker saps the battery 24/7. Hence why it goes dead. Machine is garage kept.

@TheAMMIXman No worries. It was def enough info to get me started in the right direction and while it didn't fix the issue it's a welcomed upgrade none-the-less.

 

[lone wolf]

Welp. First stump removal job that lasted more than 15 minutes and the machine started doing it again. Something I have noticed that I do recall in the past is that battery needed jumping before I started grinding. I'm wondering if the EFI motor's finnecky-ness about voltage plays a part so I've had the battery tested. Batteries+ says it's good but a bit low on voltage. This is probably due to it being dead to start with and only running for a few minutes before I got fed up with it. Spending the night on a trickle charger and will report back with whether or not it works. Long shot but here's hoping.

Side note. The machine is "lojacked." I'm guessing the gps tracker saps the battery 24/7. Hence why it goes dead. Machine is garage kept.

@TheAMMIXman No worries. It was def enough info to get me started in the right direction and while it didn't fix the issue it's a welcomed upgrade none-the-less.

Whats a GPS tracker cost a month?

 

[CDTS447]

Would have to ask the finance company.

 

[lone wolf]

Would have to ask the finance company.

Is that in lieu of insurance or what?

 

[CDTS447]

Is that in lieu of insurance or what?

Nope. Have that too. Kind of silly if you ask me... company requires it for all machines they finance.

 

[lone wolf]

Nope. Have that too. Kind of silly if you ask me... company requires it for all machines they finance.

Thanks , what State?

 

[CDTS447]

Is there supposed to be vacuum on the hydraulic reservoir when you you pop the cap? Wondering if it's supposed to be vented.
Whenever I pull the cap there's a rush of air. Maybe this is causing too much load on the motor?

 

[lone wolf]

Is there supposed to be vacuum on the hydraulic reservoir when you you pop the cap? Wondering if it's supposed to be vented.
Whenever I pull the cap there's a rush of air. Maybe this is causing too much load on the motor?

I doubt there should be a vac generally speaking.Try leaving it loose for a test.

 

[CDTS447]

Left it loose and couldn't recreate the issue here at the shop but that's not proof enough for me... i only have a few logs here to grind on and they're getting kind of sketchy to do so from all the testing. Guess a trip to vermeer and a new cap is in order to be on the safe side.
The more I think about it the more it seems like this might be it. If it gets hot I have more issues. My guess is due to fluid expansion with no venting leading to higher pressures in the hydro system, more strain on the motor. The only concern is the idle doesn't smoothe out immediately after kicking off the cutter head. Not overly familiar with the hydro system's schematic but there may still be residual pressure on the system after its disengaged? Input is appreciated.

 

[CDTS447]

PROBLEM SOLVED:
On the left (rear) cylinder head is a hydraulic lifter actuated fuel pump. A recommendation to check that valve seats led me to inspect the high pressure pump rocker lever which was bent eeeeever so slightly with a hairline crack near its fulcrum. Depressing the arm to compress the spring resulted in the arm splitting in two.
If you have problems with the machine bogging out, check the fuel pump. 50 dollar part. 10 minute fix. Make sure you depress the intake valve before installing the new valve cover/fuel pump and install everything to proper torque specs.