DHZ 140, full throttle dead spot

[motoXXX]

hey guys ive had my dhz 140 for a week and abit now and for the first few days it was goin hard and great no its still goin good but the plugs are getting rele black and need cleaning all the time so im guessing its running rele rich and also when idleing or crusing then u just full throttle it its just dead and if u held it on full throttle for like 2 seconds it stalls its ok when u got the revs up then give it full throttle but still a little bit dead just wondering what this could be thanks guys

 

[Pittin]

do you keep the airfilter clean? maybe its all cloged up and not letting enough air in.

 

[crazzy #1]

thats called bogging my friend! clocked air filter, restricted fuel flow, wrong getting and poor exhaust are the cause of this (most commonly the jetting and or air filter)

 

[no_crf50_here]

replace the 30mm with a new 26mm carbie - easy fix & works 99% of the time

 

[motoluver]

The "30mm" is a 26mm carby.

 

[Custom]

check your float level and try raising the e clip on the needle a notch

 

[motoluver]

With my dhz, the e clip is on the highest notch, stock slow jet with a 105 main jet and the air screw set at 2.5 turns out. Thats what worked best for me.

 

[SnItChY]

hey me ol mate u can try thr e-clip
just look top of carbie where the cable goes in
unscrew that then lift the cable black slide thing( im no mechanic lol)
push your spring up till you can get cable out then u should be able to remove the needle and on the top of the needle there is a small clip
e-clip u can move that up a notch and put back together and see if that solves it for ya

that should lean the bike out a lil

i hope some1 who knows stuff like cactus -jack drops in he is the guru hehehe
as im only a noob meself and blunder me way thro

 

[SnItChY]

hey i hope ya fix it me olmate
like i said tho im no mechanic nor claim to be and i just blunder my way thro life but keep an eye on ya thread and some 1 who nows stuff will explain it better for ya

 

[motoluver]

Take a look at this. http://www.elstars.com.au/pdf/manual/mik-c25m.pdf
* 8, 9 is the needle and the e clip. My clip is set to the highest notch on the needle.

*21 and 36 is the slow and main jet

(The middle jet is also a main jet but not the type used in these carbs. The main is on the left and slow on the right.)
The air screw on the dhz "30mm" carbs is found here

 

[Cactus Jack]

Hey Snitchy , you and Motoluver are doing a pretty good job as it is ! Motoluver has his 140 going good and has solved tuning problems with it before (including with a H-Bomb pipe) so he know's what he's talking about as good as anyone ... Great job showing pics of what the parts are and what they do .......

Whenever a bike is going good then starts playing up , it's always best to look for the simple things first like a dirty air filter , crap in the tank , fuel line and float bowl . ie (dirt , plastic particles , water) ....... basically make sure that everything is working properly ........

Then once you know they are alright yet the problem persists ........ do the jetting alterations that every other owner of the same engine / carb combo has found to be the best .....

I simply try to point people in the right direction then rip the training wheels off while they're not expecting it .... LOL ...... it's great to see others having a go ....

 

[motoluver]

Start at 2 turns out. 1 turn = 360 degrees. Mine is set at 2.5 turns out. Make sure you have a clean air filter on it and ALWAYS oil it after cleaning it.

 

[crazzy #1]

clean the plug! (replace with a new one) clean carb, clean air filter and clean tank and fuel lines then see how it goes...

also add a fuel filter!

done the above (to my sisters crf150f which has a similar problem) stopped coughing and splattering top end... for now

 

[crazzy #1]

get your hands dirty and do it yourself