Importing and modifying a new mini excavator from China

[MTGreen]

Not sure if it is the cold (was below freezing overnight but it is now at about 40F) but this morning I can not get my B&S engine to start. Checked the spark and it sparks, can see fuel fouling the plug when I pulled it (did not realize it is a crappy Torch brand will replace as soon as I can get a NGK for it) after several attempts to start it does not want to fire off. Does not matter if choke is on or off, throttle open or on low setting.

Since I see spark it can not be a oil sensor or some other ignition issue and because I see and smell gas it likely is not a fuel issue.

Anybody got any ideas other than having it get warm outdoors?

Starting fluid?

 

[dfkrug]

Checked the spark and it sparks, can see fuel fouling the plug when I pulled it (did not realize it is a crappy Torch brand will replace as soon as I can get a NGK for it) after several attempts to start it does not want to fire off. Does not matter if choke is on or off, throttle open or on low setting.

First, all these Honda GX-clone engines you buy today are set very lean. They hate cold weather and need full choke to start. If you flood it and foul the sparkplug, that has to be dried out before you will have any luck starting. A crappy plug makes this problem worse, but I find that rare.

Try this: Dry the plug or use a new one after you see it all wet with gas. Put it back in and try to start it with fuel petcock off, choke off, and throttle open. Pull at least 5 or 6 times. That will flush out the raw gas from the cylinder, or even start. 10 times even better.

If that does not work, do it again, but spray some starter fluid into the carb first. Use ether type spray can, not gasoline.

If that does not work, you need to check that your valve clearances are not too tight (low compression). this is very easy to do since the valve cover is accessible.

 

[MattB4]

Starting fluid?

Looks like the day just needed a chance to warm up more. I tried again at 1pm my time (47F) and after some cranking the thing fired off. It was rough though and needed the choke for a while as the cold hydraulic fluid was hindering operation.

I probably need to work on a means for starting when the weather gets cold. New spark plug, starting fluid and perhaps a magnetic engine warmer to attach to hydraulic tank. Real pain in the butt when you are set to go do work and the engine refuses to run.

ETA: BTW over several years I learned to distrust Torch brand spark plugs. The most annoying fault I had with one in a lawn mower was the mower would start easily and run great until warm than quit. It than would not start again until the mower was cold again. I pulled out my hair trying to diagnose why it was doing this until I changed out the Torch spark plug for a Champion. The problem went away. Seems it would spark when cold but once it got hot it would quit.

 

[D'oh]

Lots of Choke, Mine New One started this morning @ 19F. B&S's are on Snow Blowers without any Engine Heater. If truly needed, a 100w Trouble Light under the Seat would heat things up alot.

Got the QH12 back to Town Yesterday, 2650km Round Trip, it Cranked and Cranked, no go. Had Spark, turned out that the Carb was filled with a Vaseline type grease, that I guess doesn't just wash away @ 20F.

Sold the QH12 Today, so all is good. Paid for the trip to get the Stand On.

 

[jaylast]

When I referenced 'hydro tensioner' I was referring to standard excavator grease style. To me hydro just means 'fluid filled' whether that's grease oil or water. Interested some of the high end types.

 

[jaylast]

The Diggit may have an internal weight like my XN08 has. Newer machines (most of them now) use an external casting that increased counterweight from 75 to 100#, according to my measurements. The EM15 has a slightly longer rear of the house, which itself is a counterweight.

I dunno why you say the pump is a limiting factor. If the relief valve is properly set, you will be able to go up a 40% slope if the surface has good traction. The only time my wheel motors stall is when I get a small rock under the track. I can pretty much guarantee that your RV setting is low.

The small open-center valve blocks for the boom, dipper, swing, and bucket are under each arm rest next to the seat.

One more thing about the EM15: the one I opened up had no hour meter. Does yours? If so, where is it mounted?

Thanks, I'm going to weigh it the first chance I get, really curious. Plenty of room for more weight down low on back and sides too if wanted like several cubic feet I'd say. The low power is probably just my expectations too high, haven't tried high grades yet for reference but sometimes when turning on grass one track or the other doesn't seem super responsive/powerful. Will be checking and tweaking stack pressure eventually for sure.

For now just messing with body panels and tweaking things for easy removal. It's practically stupid how gaining access to some areas requires removing 3 or more panels/things.

I suspected for the size of the filter it could limit flow (based on hose size). Turns out it's similar to some hydro cooler setups that only cool some of the oil at a time. . . the only thing it filters is just one single return from each joystick, 2 total. The other two returns from the other two joystick functions (each of 8 functions have returns right?) go directly to tank, whereas these two go thru filter, but then back to pump side of valve body right above the pressure tank thing on bottom (blue label closeup in pic). Figured they would also go to tank but surprisingly no.

It did come with one extra filter. But no hour meter and no hydro thermometer.

Pretty slick machine(s)- it's just weird yah have all this effort and capital to design and manufacture, and a bunch of little stuff is completely overlooked that would really improve the product at virtually no extra cost.
Gives me doubts there aren't the same oversights in the actual mechanics of the thing where more small changes could greatly improve overall operation/performance.


To all you guys with some hours - how much slop is normal after how long?
After three hours I've noticed joints in arm and bucket a tad sloppy (plenty of grease and all pins tight), (prob from factory?), But most importantly the house has several degrees of side to side /turning slop whether machine is running or not (will measure, but guess > 6 inches at bucket with arm fully extended.) I did verify the bolts to motor and table are tight- seems it is in the motor itself or it's interface with the ring gear.

 

[jaylast]

Dkfrug, I'm beginning to think when you mention 'open center pilot' that just pilots are open centr (4 total) defined by each needing it's own return?
I guess the other 4 spool functions (mechanically operated spools) on main stack return their pressures back one of their two hoses into main stack and eventually from there to tank.
It's making a little sense. Would love to find a utube vid of someone going into specifics for these and similar systems.

 

[dfkrug]

...when you mention 'open center pilot' that just pilots are open centr (4 total) defined by each needing it's own return?
I guess the other 4 spool functions (mechanically operated spools) on main stack return their pressures back one of their two hoses into main stack and eventually from there to tank.

Both servo control joysticks control 2-spool open center valves. These each have their own tank connections that could go directly to the tank, or thru the 8-spool main stack valve body. All 8 of those valves return fluid to the tank thru one internal galley. Your machine actually has 12 total spool valves, including the 4 servo valves.

 

[jaylast]

Thanks for the replies and info dfkrug.
So the whole system is consider open center because it doesn't dead end anywhere and makes a full circle.
When you say servo though- these are not electric in any way? Considered pilot valves I guess since they are secondary to the primary spools? Yes, 12 total since it's a valve controlling the main valve for the 4 joystick functions.

I'm not super happy with the slop I already notice everywhere- guessing it's fairly common though. I took the slewing motor off to examine the house/swing slop and it's not the mesh with ring or the keyway /key, the slop is coming from inside the pump/gears itself, and of course just a little turns into quite a bit for the boom. Here's some pics/vid of it and cover removed. I wonder if this is because of a low quality pump. youtube.com/shorts/t_S8iINJvAQ

 

[dfkrug]

Thanks for the replies and info dfkrug.
So the whole system is consider open center because it doesn't dead end anywhere and makes a full circle.
When you say servo though- these are not electric in any way? Considered pilot valves I guess since they are secondary to the primary spools? Yes, 12 total since it's a valve controlling the main valve for the 4 joystick functions.

I don't know where the term pilot valve originates, but it is what hydraulic servo valves are usually called on excavators.

Your joysticks operate very small spool valves that actuate small slave cylinders on top of the main spool valve stack. These open-center (tandem center) valves have continuous flow from the pump thru the valve body, until a valve is actuated, sending fluid to/from the cylinder.

There are no solenoid valves in your system, except for the cutoff safety valve that stops flow when the power is off.