QLINK Starting Problems

[Mark Popeye]

The CDI is $32.  Still searching for ECM (unless they're one and the same).  I was told there are multiple computers on my UTV.

[kenfain]

$32 bucks isn't bad, if that turns out to be the spark control. 

[Mark Popeye]

So, got it back from guy working on it.  I ended up mounting a deep cycle marine battery, in the center, battery supposed to be for it, doesn't want to start.  Runs but won't engage 4WD.  No matter which way button is.  Looking to sell it asap but would like the 4WD to work first.

[kenfain]

Have you checked the button, to make sure it works? Next would be the relay (I'm assuming that it's electrically activated since you said button). Then there's the actuator in, or near the differential. 

[Mark Popeye]

The button shows on the dash, after pressed.    Just what I want, more stuff to check.  Not even sure where to look.  Any idea where I can see a manual?  Maybe there's something I'm missing?

[kenfain]

No idea about a manual. But unfortunately it's all about the testing stuff. See if you can easily find the actuator at the differential. Or wires going inside the diff. Test for power from the switch. 

 

[Mark Popeye]

So, I have it jacked up but fronts don't spin (no matter whether I push button or not).  I had it unplugged at differential and tried to find voltage (volt meter) .  Saw nothing (unless I am doing it wrong).  Is there a relay for this?  If so, do you know which one it is?  Looking around battery box and see what appears to be several.  Googling it is not productive at the moment.

[kenfain]

Simple 12v switches are weak. They don't have what it takes to handle any real type of load, like an actuator. So that's what relays are for. 

So it's almost impossible for there not to be a relay to run that 4wd actuator. Which one it is, I don't have any clue. The good news is that they're usually all interchangeable. So while they won't interchange with the ones on your car, or truck. You should be able to switch them out with the others in the same fuse panel. 

There's several ways to go about this. If you can find the wires at the actuator, and verify the same colored wires at the fuse panel. That'll tell you which one it is. 

Or another way is to just find out if you have a bad relay period. By using the interchangeability to test in a known good circuit. Like the headlights, or horn, or winch. Pick a relay, pull it, see what doesn't work. Might take a couple of tries, to find one suitable. Use that circuit to test the other relays. Only do one at a time, put it back, move to the next.

 

[Mark Popeye]

Yea, the relays I've found (by battery box) all seem the same, except for the directional's.  Can't really chase wires from differential back, as they (for some reason) go under the unit.  No way to access them from there.  Unfortunately, the same colored wires (at differential) don't match any of the relay harnesses, so that makes it more of a challenge.  Will try swapping relays around and see what happens.  I have a local looking into it and may pay him to figure it out. 

[kenfain]

I've never seen a Qlink, but my understanding, is that it's a Rhino clone. There's plenty of information out about the Rhino. So if it's actually a clone, then the wiring would likely be more than similar. If not exactly the same. Since it's very unlikely that the Qlink manufacturer would try to fit the same components in, using a whole new floorplan. I think that it's a good bet, that the wiring would be the same as well. Might find some answers there at least.

[Mark Popeye]

So, I replaced all relays (because I couldn't find info on which one is for 4wd).  With UTV on blocks, the driveshaft turns but not the wheels.  Ended up buying a brand new snow blower and going to post this for sale.  Was hoping to have the 4WD working beforehand.  

[kenfain]

Well it's a process of elimination. Every component has to be individually checked. This takes time, especially when we do it through online media. But if you're willing to stick with it, we can do this. 

Have you checked the actuator? They probably call it a servo. It should be a black box mounted to the back of the front differential. It'll have contacts that need to be checked, to see if they're burned. Next up, and the most likely culprit is the servo motor.

[Ben1098]

Travis was on the right track.  You have a strong running engine after you get it to start.  The split vac hose was just a bump in the middle of the search, right?  Carb/fuel problems will generate runability problems before and after starting.  Bad connections, weak battery, parasitic drain, burned solenoid contacts, worn starter brushes reduce the power delivered and used to crank it over.  Travis test of pulling spark plug...you said the motor spins over just fine with the spark plug removed......no load except friction and valve spring loading.  You video was the TELL.  Compression release is not doing it's thing.  Totally random as it depends on where the motor stops (how far from the Compression stroke)    AND    how long the motor set since last crank/run......oil drain down and piston/rings get "DRY" lowering the compression.  Fog cylinder or crank to splash/lube piston/rings....compression climbs back up.

Physical example.....you want to push a small car on a level driveway into the garage.  Problem is the rain shedding slope or a seam in the pours at the door.  Would you push to the incline or bump and then STOP only to then try push it up the incline or over the seam???  NOPE, you would take a RUN at it.  Same for the poor starter......no compression release.......grunt city per the video clip. 

The clip shows the "front" of engine with the intake valve cover (double lid) but not the exhaust.  3 valves?  Maybe 4 valves?  Should have a 2 into 1 exhaust header and 2 ea of the round screw off caps for adjusting the exhaust at the "rear" of the engine.

Compression release works by SLIGHTLY opening for a SHORT time an exhaust valve during the compression stroke.  Less grunt....motor gets a RUN at spinning over faster which will build compression more (less time for the slight EX valve to be open and leak off some of the fuel/air mix) to the point it is high enough to light off.... if the fuel/air mix is right.

Exhaust valve adjustment is set between the rocker screw adjuster and the valve stem top face.  This is important for the RUN function.  The START function will be hindered if the valve is set too loose (wider gap) as it cannot open the valve slightly as much or not at all.  Too tight will result leakage.....burnt valve seat/face when the whole motor warms up and EXPANDS as in the valve stem gets longer.  ADJUST THE VALVES.

FOR THE DOWN SIDE..................there are a couple of BAD things to go wrong.....one was a incorrectly machined flyweights (located on the camshaft gear) from factory and the other two are wear of the compression release "CAM" (located inside the valve camshaft)    OR    the ball/pin had worn a grove in the rocker/follower.  ANY of these will result in NOT opening the EXHAUST SLIGHTY for a short DURATION=COMPRESSION RELEASE.  ADJ valves and go from there. BE sure to get off the compression release section and only have the slipper pad adj screw to valve stem face....that that can also have wear problems.  Lots to check here but that is what it is. 

The last problems require the rocker cover and cam to be pulled along with IF a pin/ball grove cut into the rocker/follower.  The factory mistake can be fixed with a burr and die grinder (gets too deep for here right now of what and why details).

 

[Ben1098]

DIFF problem....you will have 2 connectors...one to switch power + to - and - to +......this runs the small electric DC motor that slides the rack (behind/under the black round shift servo) from left to right to left.  There are 3 positions.....2 WD, "3 WD" which is an open diff where if front end is lifted, the wheels rotate in opposite directions (with drive shaft locked) and then 4WD which locks BOTH fronts together.  Someone in the past has shifted into 4WD UNDER LOAD (and moving)....SNAP CRACKLE POP with emphasis on the POP.  DO the rack test (remove the black shift module....bolts here.....and slide the rack L to R to L.  Be aware that the position of the rack has to be "timed" to the servo unit.  Write down the dash switch(s) position (I like 3 WD) AND where exactly where the rack is sitting (in the middle slightly off center for 3 WD).  Test the servo by having another person run the buttons and you look for the gear to turn and motor to buzz.  The gear will go CCW and CW and CCW...exactly the way the rack should slide back and forth to select the desired function.  If the rack slides with no resistance from side to side...internal busted push pin on rack.  If working, the rack will move slightly and then stop because you have to rotate the wheels (spin the diff) to align the diff gears and then finish the "shift"  The servo has a "wind-up" spring between the electric motor drive and the gear output that "winds up".  What this does is put pressure (like you are doing with your hand) on the rack waiting for the gears to align.  There are contact tracks/Cu brushes (limit switches) that rotate with the drive reduction gears to send back 12 v OR open to electrically shut off the motor power so as to not bust up the works....winds spring up waiting for alignment....but not over driving the plastic gears.

DECOMPRESSION problem.  You have 2 exhaust valves (depending on the year either 2 or 3 intake valves).  The exhaust valve on the far side (away from the cam gear AND center located decompression cam/flyweights/springs) has 2 functions.  When starting the flyweights are IN (spring tension) and the DC cam is rotated to push up a pin that rubs the rocker pad.  The exhaust valve then opens slightly as long as the pin (5mm ish Dia.) is rubbing on the rocker pad.  SINCE the valves are adjusted at TDC on compression stroke, there is a chance you might still be sitting on the pin and not know it-----wrong valve adjustment.  The fix is to rotate past TDC then come back.  You should hear and see the valve do its thing.  You will see a deep stroke on both exhaust valves BUT only a slight opening from compression release function.  Again there are 3 things found wrong in my past experience.

 1.  The pin had chipped out a groove in the slipper pad........no longer opened enough--the quick death method--chunks out at one time.

2.  The decompression cam (in the center of the valve cam) has wear on the corner edge and gradually gives a shorter pin stroke length AKA, slow death.

3.  Factory defective part.  Hard to crank out of the crate.  Found in BOTH Yam RHINO and HISUN Massimo.  THE mistake IS identical----same supplier for both!!!!  The fly weights are stamped main body and an extra "weight segment" welded to the main body.  Extra weight was not aligned at weld station correctly and resulted the DC cam having reduced rotation....thus a die grinder fix. 

Q-LINK Youtube video posted on cam replacement.  Entertaining on the chain/cam timing with CUT AWAY.  HE! HE! HE!

Give this post and video to the fella you are going to have a look see.  Should give insight on what is happening.