Brand New DHZ Dpro160 Not Running Well

[Harty89]

Hey All,
I have just bought a brand new dhz dpro with z160ho engine. The thing is it back fires, serges, splutters and doesnt rev out in gear. If i give it a rev in neutral it'll go not to bad. Hold it at a rpm it back fires and shoots flames. Looks bloody cool but not what i want.

So i've checked all wiring connections, valve clearances and pulled the carby appart. Played with needle heights. Main jet is 100 and pilot is a 20. Is 20 correct for out of the box? The engine seems like its running rich if anything and takes a bit for the combustion to clean up.

Help please.

Daniel

 

[Gloverfmx]

just take it straight back to ken and kc and they will sort it out for you dude, just give them a call

 

[Harty89]

Thats plan B. They are currently on holidays plus i live in central queensland. So any ideas?

 

[SnItChY]

ok so have you looked for an airleak , spray some wd around the manifold , if revs change you have a leak


sounds to me tho the valves are out

 

[Harty89]

When you say the valves are out do you mean tappet clearances or timing?
Also it back fires back through the carby sometimes.
As far as carby settings what should they be; Needle position? Main Jet? Pilot Jet? mixture screw turns?
And would it be worth playing with ignition timing?

 

[DHZ_XR8cing]

Id say valve clearances mate.

 

[!bmth!]

yeh mate sounds to me that you need to do your valve timing there is a really good thread of here thats tell your how to do it but i cant find it ahve a look in the tutorials section its there somewhere

 

[sean01]

not valve timing, valve clearances... totally different things...

the bike should run fine straight out of the box... if anything it should only require the needle height set, but again it still should run pretty much fine...

if you've double, triple checked the valve clearance and it fine then try and get access to another carby the same as you got, occasionally you do get a dud carb...

another thing to try is the cdi or coil... but sounds like one of the 2 above...

 

[!bmth!]

yeh sorry sean i meant to say clearences

 

[DHZ_XR8cing]

This might be a stupid suggestion but sometimes it is overlooked. Make sure you have your choke is turned off

 

[coolmodee01]

may be float levels or more likely an air leek

 

[clunky64]

not a stupid suggestion dhz symptoms sound very close to that

 

[sean01]

actually these bikes are running the mikuni 30mm carb with the plastic choke arm hey?

if so then it isnt unheard of for the choke to be pulled on with acceleration. you need to unscrew it off the carb and put a small bend in the plate...

 

[warners.90]

My DPRO160 has the same problem as this.

HARTY89, what as the problem in the end?

 

[DHZ_XR8cing]

Did you check all the things suggested in this thread warners?

 

[warners.90]

I've checked the choke, I did that first because my old bike had a jammed choke and i could work it out.

I've done the clearances numerous times, because thought i was getting them wrong or something, but i'm pretty confident i'm doing it right.

I've haven't played around with the carbie yet, because i'm very unfamiliar with them. Plus i've heard there is plenty to stuff up with it, if i do it wrong. Plus on the occasions it does start and fire properly, it revs well and sounds good (with exception to the idle not quite being perfect) so for that reason i don't think it is a major carbie issue. So i recon i'll make things worse by playing with the float and jet settings.

I got a feeling it may be due to timing issues. Given that if the engine is shut off properly, and i get it to start first kick it basically runs properly every time. However if it: stalls; or, I don't get a start on it, first kick (and the engine turns over); or, the engine is turn off after it has been firing like crap; it rarely starts properly.

I haven't check whether the exhaust nuts are tight to the head, i'll do that when i'm home next. I'll also spray some WD around the area to.

The other thing after the exhaust shone bright red after i idled it for a few minutes with the new spark plug i was really concerned. Any change the oil cooler is blocked or something?

 

[motodevo]

If the exhausts was glowing it's most likely running lean, probably blocked jet/s. If it doesnt wanna idle I'd say you have a blocked pilot jet. Also not trying to tell you how to suck eggs but you do know how to start a motor properly(getting it to TDC first). Mate if you had no problems doing clearances carbs are easy peasy just make sure it's totally clean and then clean it again! Also put an inline filter on your fuel line to stop any crap in the tank making it's way into your carb

 

[DHZ_XR8cing]

Sounds like crap in your carbie if the problem comes and goes. try to clean ya tank out and put a fuel filter on it aswell after you have cleaned your carbie

 

[Harty89]

I originally thought it was a combination of stale fuel and leaning out. When i took it for a proper ride i oiled the filter and put premium fuel in which appeared to fix it. However the intermittent nature of the problem had sorta pointed else where.

So now i suspect the spare WIRE was GROUNDING against the frame. My brother bought one after me, took it for a ride and and then started doing the same thing. He taped the end of the wire properly and the problem went away.
All in all i great bike! Some adjustable shocks is defininetly on the cards but.

 

[warners.90]

Did taping the wire on your bike fix the problem; or did it just fix your brothers?