Start up issues, not firing properly every time

[warners.90]

I've got a DHZ DPRO 160 with the z160HO engine, except the thing is working properly all the time.

Some time when i start it the engine fires perfectly, revs smoothly etc. Other times it will splutter upon start up and if i'm lucky i can squeeze the throttle and it will all just into line and start revving properly and create the normal amount of power. However the problem is some time it starts and just fires like crap, it will splutter and will hardly rev.

- It maybe important to mention the engine is fairly new.
- I've done the valve clearances (and i'm fairly sure I have done it properly).
- I was told the breather hose on the top of the case may have been kinked, but it isn't.
- If I kill engine properly and get a clean kick it starts fine usually, but if it kind of turns over a little before i get a good kick it tends to start like ****. Which makes me think it is a timing issue or something.

I've been told to change the spark plug so i'll do that tomorrow, but i doubt it is the problem because when its running it seems to spark properly and create plently over power.

Another thing is it doesn't seem to idle perfectly, which indicates to me it may be a valve timing issue but i'll check that a number of times i'm sure it has to be right.

Any advice you can offer will be greatly appreciated, cheers

 

[sean01]

sounds like you need to tune the carb mate.. is it still the stock carb?
only use 1/2 choke when starting it cold..
and dont use any crazy amounts of throttle when starting it
only bit i ever use is just enough throttle to take up the cable slack and just hold it on idle, other than that i hold it wide open if i feel its a little flooded..

might be worth checking your float level in the carb, it may be bleeding into the engine while sitting but not enough to drip on the ground...

 

[warners.90]

Yeah, its got a stock carb.

It may be flooding, it is a bit of a **** to start alot of the time, and i usually use full choke. I'll give half a go.

The other thing is the bike has started recently (as the start up issue discussed above has been getting worse) back firing and crackling as it revs down through the gears under no acceleration.

Can you recommend any videos on adjusting float heights and carbie settings?

 

[sean01]

the crackling can be your exhaust coming loose at the head... this sometimes can make a bike hard to start

 

[warners.90]

I'll check that out.

I just put the new spark plug in and after only running for a minute or so it became RED HOT. The oil cooler was only slightly warm and the casing had hardly had a chance to warm up as well.

I've just got no idea what is going on.

On the bright side, once i eventually got the bike started, it started again easily and without to many hicups. but it did struggle to fire first off (on half choke) and full choke made it easier.

 

[warners.90]

I think it is also back firing through the carb, as numerous times smoke has come out of the filter, if it kicks back on an attempt to start up.

 

[ilikemotorbikessoverymuch]

What was the problem in the end?

 

[warners.90]

Still looking mate.

 

[ilikemotorbikessoverymuch]

Still looking mate.

I'd reccomend posting a video on youtube of whats wrong with it. Many of my mates have done that when there bikes are screwing up and it worked for them. Because a lot of people on here probably dont know exactly what you mean but if you post a video people can see and the problem may be familiar or they just might no. Just a though though?