dhz 140 thoughts?

[boston460]

hi all new to the mini side of dirt bike ridding, been ridding larger dirt bikes for many years thought the minis looked like a bit of cheap fun. just wanting to know peoples thoughts on the dhz 140 are they any good? i am a tall guy 6 foot plus and close to the ton weight wise, is it a flight of fantasy to expect any thing in the sub grand price bracket to not to explode if i point it at anything bigger then a speed hump, sorry if this has been asked a million times but the search wont work for me.

 

[motoluver]

Hey I just got a DHZ 140 the other week. They are very very similar to the pitpro 140. Only minor differences between the two but the DHZ 140 is a little cheaper. I'm not tall and only weigh around 55-60kgs. Stock form they are a good bike for the price (I paid $880) posted. They handle pretty good, have a good Lifan motor and overall they are good for the price. Some people will tell you that they don't have 30mm carbs on them but that is ******** i measured the carby my self it is indeed a 30mm carb. I am happy with me decision on getting it. But at your height and weight i cannot help you out

Oh and for some reason the search function is stuffed. I have to right click "search" and then "open in new window" for it to work.

Check this out as well
http://www.miniriders.com.au/forum/showthread.php?t=10248

 

[Cactus Jack]

Some people will tell you that they don't have 30mm carbs on them but that is ******** i measured the carby my self it is indeed a 30mm carb.

Those carbs are NOT 30 mm - they are actually 24 mm diameter slide oval bore carbs making them the equivalent of a 26 mm carb . They have a 30 mm outlet bore - but you size a carb by the diameter of the slide , NOT the outlet bore ! The oval thru the slide area is 22 mm wide and 30 mm high at full slide lift - IF you got a rubber 0-ring that fits , it would be 26 mm in diameter and that's the true size of the so called "30" mm Mikunis . Aside from that - measure the bore thru the inlet manifold and IF it's not 30 mm in diameter to match the carb then it's completely ridiculous as the carb can't supply any more air than the the manifold can flow and the mismatch will cause turbulence ! There's not much point in going any larger in diameter thru the slide area of the carb than the size of the area thru the inlet valve throat (minus the area taken up by the valve stem diameter) as the resultant velocity drop will cause a loss of bottom end torque plus hesitation and bogging when the slide is opened quickly !

Sizing a carb by the outlet hole is the equivalent of measuring the distance from your butt hole to your navel and claiming that you have a 12 " dick !

 

[motoluver]

Ok thanks for that. Is this a good thing or a bad thing because I have heard that 30mm are to big for Lifan 140s anyway? Yeh that would explain why the manifold has a 26mm bore. In the future i plan on upgrading to a genuine keihin I always thought Mikuni's where junk. What size keihin do you think would be a good upgrade for the Lifan 140?

 

[Cactus Jack]

Ok thanks for that. Is this a good thing or a bad thing because I have heard that 30mm are to big for Lifan 140s anyway? Yeh that would explain why the manifold has a 26mm bore. In the future i plan on upgrading to a genuine keihin I always thought Mikuni's where junk. What size keihin do you think would be a good upgrade for the Lifan 140?

I bought a "30" mm carb kit off DHZ just to get the manifold and I'm going to get rid of the carb ! The way they flare out a lot bigger after the slide isn't too good for air velocity ! The "25" mm Mikuni carbs are 22's in reality and it's printed on the float bowl - they have a 20 mm slide which is lifted 25 mm high and they have a 25 mm exit so they'd probably be better to use !

Yes - the 30 mm hole hitting a 26 mm hole in the manifold is BAD ! I've thought of puttying up the carb with epoxy or making a tapered reduction spacer / adaptor between the carb and manifold but it's a lot of messing around .

A carb with a 24 to 26 mm ROUND bore thru the slide area and 26 mm exit bore that matches the manifold would be the go ! Also - get a 4 stroke specific carb - There is a 24 mm Keihin kit that would give good response along with excellent top end power but they're pretty pricy !

http://cgi.ebay.com/ebaymotors/NEW-...ItemQQcategoryZ35597QQitemZ130095710223QQrdZ1

This TB 108 Stroker kit has a 22 mm Keihin but they are claiming it's a 24 based on the outlet bore :

http://www.powersportsstore.com/ebay/trailbikes-xr50-stroker-kit-wcarb-1-large.jpg

A 22 mm Keihin off an early model SL/XL 125 Honda would also work great as they have a 24 mm exit bore and they can be opened out to match the manifold . I use them on modded XR80's . Having the carb exit bore 1 mm smaller all around than the manifold bore helps stop reversion waves from reaching the carb . Reversion waves go back past the jet and then come back again , meaning the air has gone past the jet 3 times picking up fuel each time - that makes the engine run rich , sluggish and have less response at low revs where the waves are strong and you CAN'T tune it out ! The exact opposite works for exhausts as in stepped headers !

There's also a 26 mm XL175 / 185 Keihin carb as well . Don't bother with carbs that have a skinny slide that gets lifted higher - they're low performance pollution carbs for trail bikes .

 

[daniel40]

i know this guy who has a dhz 140 he jumped it and the front wheel came up and smashed his oil cooler off

 

[motoluver]

I don't think thats possible even when they bottom out. And saying that your also saying that the DHZ,PITPRO and i think one of the MSO can all do that as they run the same frame and i know the DHZ and PITPRO run the same forks?

 

[daniel40]

im just saying thats wat happened to him it smashed it off but it was a massive jump

 

[tubes380]

it wasnt the same type of frame he had a single tube alloy frame the dhz/pitpro frames are dual cromoly and heaps stronger