Sullair 185 Compressor stalls

[Bibendum]

Good day,

I’ve an older (80s model) compressor that stalls when cold. To allow the machine to run, I’ve got to crack open a hand valve to take the load off the compressor. Once everything is heated up (15 minutes or more) I am typically able to close the hand valve and the compressor will run and maintain pressure at idle.

There’s some fiddling that’s been done to the throttle / governor linkage as the motor was replaced with an “iron duke” and the intake is on the opposite side as the original motor. Fuel flow and pressure are good.

My main question is this, as I’ve never fooled with a large engine driven compressor except for this one. Is typically there a clutch that disengages the motor when set pressure is reached? There are some pilot lines that run to the bell of the air end, and seem to sit behind what looks like a clutch, but if it is a clutch it certainly doesn’t do it’s job. I cannot find and technical information to this compressor online.

 

[BillG]

Carbureted I presume, what temps are you talking? Being Canada it could be lower BC which the temps can be mild to the NW territories which is damn cold. It's not unusual to have to let an engine run in cold temps before it warms and the manifold will keep the gasoline atomized. 15 Minutes seems reasonable to run unloaded. No different than the folks that would start their car and immediately expect it to do highway speeds. That would result in having to restart a few times. Does the carb have an auto choke or manual? Block heater?

 

[Bibendum]

Hi bill, eastern Canada so somewhat of a mild winter. Average temp of maybe -10 c. That said, it’ll get to -30c for a week or so normally every winter.

It’s now a manual choke. There was a check valve and filter in the carb bowl to keep fuel from draining back to the tank that was jammed packed so that’s now gone. In-line clear plastic filter before any of that. Other than that I had the carb off and cleaned it although aside from the filter in the bowl it really wasn’t all that dirty.

That said, it does the same thing in the summer. I set the air pressure up in the summer so the air is denser now I suppose.

 

[1693TA]

I always declutch the compressor from the engine and allow it to warm prior to placing the load upon it. I do this in the summer, and winter months always.

 

[Bibendum]

I always declutch the compressor from the engine and allow it to warm prior to placing the load upon it. I do this in the summer, and winter months always.

That makes perfect sense to me, I just can’t see how / what operates the clutch, or if the clutch is even functioning.

The more I think about it the more I’m starting to think the compressor isn’t being unloaded.

 

[Dave Neubert]

If your unloader pressure is set to high it will stall the motor try turning it down a bit

 

[funwithfuel]

If your unloader pressure is set to high it will stall the motor try turning it down a bit

Or if the unloader is perforated.