Z160HO engine issues

[gixxerdims]

A few of us bought DHZ 160 motards end of last year/start of this year.
On one of the bikes, we've had a couple of issues with it.

We had an issue with 2nd gear, wouldn't go in properly, constant false neutral and ended up having to replace the gearbox so we pulled apart the engine and did that. At the same time we threw on an OKO 26mm carb.

For the next two times we took the bike out, ran absolutely perfect, no issues.

Third time took it out and the bike ran like absolute ****. Sputtering, and kept on dying, and that's only when it would even start!
Checked the timing, looked OK, pulled the clutch cover off, everything looked OK there, took the head off, valves don't leak fuel/water and don't looked damaged etc.
Everything looks fine. Put it all back together, still ran like crap. Swapped over to the stock carbie, would idle a little bit, but as soon as you crack the throttle just backfires a lot through the carbie.

Timing looks ok, we tried to make sure were weren't 180 degrees so adjusted that, pretty much ran exactly the same, made no difference at all.

Any ideas? To me it sounds like timing, but we just have no idea why the bike is running like this!

Anyone around the Melbourne area that can help us out? Don't want to take it to a shop as we generally don't trust a lot of shops, that's a different story but anyway, my mate just needs to get this sorted.

 

[motorman]

If you swapped over to stock carbie and it started I would say it's your jetting in the oko that's the problem.

Maybe a clogged pilot jet. Give the OKO a good clean out and blow all the jets out.

 

[Trains]

pull the bowl off the OKO, you could have water in there. also it could be an electrical problem. ie. Coil, Stator or CDI.

 

[gottagetacheaperhobby]

You mention playing with timing, but did you do the valve clearances while there?
Take some photos of the cam marking, and flywheel marking and their positions. Easy way to tell if your timing is right (not 180 out) is line all the marks up, and then check the stator pickup tab (little rectangle protruding from flywheel/stator) is just past the signal pickup (post next to your flywheel, mounted to the stator backing plate. If so thats the firing stroke and all good.
Definitely clean the carbie out, could be gummed up if you left old fuel in there (pays to turn the fuel off and let the bike idle until it dies if your leaving the bike sitting for a while)
Check the earth is solid, on bare metal, and not rusted. A smear of dielectric grease will prevent rust. Might pay to check the stator output if nothing else works, My67xr has a thread on checking stator readings, worth a read if you havent done it before.


Sent from my SM-T110 using Tapatalk

 

[mikkh]

Most likely the stator wounding has given up.

 

[gixxerdims]

thanks for the replies.

so just to clear up a couple of things.

The stock carbie was put back on, ran a little better, would at least stay 'on' but still ran like absolute crap. So don't think its necessarily a jetting issue.

Will check out the timing stuff you mentioned and post a pic too.

Mikkh - what are the symptoms of a stator giving up? Bike still turns on with the stock carb but just doesn't run

 

[my67xr]

Blocked fuel filter check the one in the tank on the top of the tap, and the inline one between the tap and carb, blocked breather on the tank ?
Did the bike's get wet at all?
Try pulling all the wiring plug's/socket's apart and spraying wd40 in each
Try running it with the kill switch disconnected, sometime's they fail and short on the handlebar's

The Socket that plug's into the big cdi i have seen the terminal's push out the back of the socket before
The little terminal locking tab's can sometime's be bent a little which allow's an intermittant connection
Check earth's for the coil and main harness are clean as mentioned above

My Daytona would start and idle one time when i was out riding but it wouldn't rev properly, i pulled the fuel bowl off and found my Main jet had come loose and fallen out.
Doesn't explain how 2 carby are having same problem's though.

Dirty/water in fuel as mentioned above, hold the carbry upright when you are taking it off and removing the fuel bowl and check for water

Spark plug cap's can fail too, unscrew it from your lead and use a multimeter (set to 20,000 Ohm's) to test the reading
Sometime's if it's got moisture in it the spring and resistor can corrode and cause problem's
Look inside the cap and if there's a slotted brass terminal in there unscrew it and you might be able to pull the terminal and thread's out the cable end

This is the thread Stu mentioned above for testing the stator etc
http://www.miniriders.com/electrica...urce-coil-pulse-coil-regulator-rectifier.html

It should be 5K Ohm's (5000 Ohm's)

 

[mikkh]

On the electrics thread look up Zongshen Z155HO/Z160HO/GPX125 source coil testing. It is quite common for those to give up overnight. It also explains why two different carbies are not working OK. Sometimes playing with the mixture screw and needle level makes it a bit better (but still not revving ok), but the gains of adjusting carby are short-lived.