KDX 175 1981

[BMC]

Hi everyone
i brought i KDX 175 1981 for $790 and its all there, ive had some problems over the mouths i have had it with a top-end rebuild done dew to the fact of my carb that it is making it over rev, what i am really asking does anyone have a spare carb for it because im not running the bike without a replacement of a carb or a carb rebuild kit can anyone help?

[kdx 175]

i got a carby you can have or go http://www.mikunioz.com/index.html get new one 200$you just got to work out what the juts are if you get stuk i can look in my carby to find jet size

[80-85 husky]

Maaate what can go wrong with a carb?? have you got the needle stuck when putting the slide thingy in which holds the slide up at half throttle?

is the manifold cracked and sucking air, is the slide badly worn with brass showing through?

does the slide go "thunk" when shut the throttle, should make a solid noise if its closing all the way.....cable isn't hung up on the top adjuster???

has this helped you?

[BMC]

well basically my carb hasn't been rebuilt before so everything in it is just worn, i am the seconded owner of the bike and thats what the original  owner told me
everything is shutting when the throttle is moved there is a noise but its not as load as the pe one, which i do understand there a completely different bike ?, there are no cracks in it so it not sucking in air, i havnt put the slide in wrong
but the slide is showing brass

[80-85 husky]

the carbs would be very similar but the noise on closing depends on the air filter a bit so it will be different.

If the slide is showing brass, its worn so maybe look at getting a new carb, will solve any problems you have with that one.

But! over revving is usually due to air getting in that's not supposed to be there or an adjustment is wrong.

have you set the idle mixture screw out about 2.5 turn? (little brass screw on the side of the carb) turn it in till it stops (gently!) then wind it out 2 and a half turns.

you idle speed screw isn't screwed in too far? (that's the one with a spring on it) and it should be adjusted so the bike idles nicely at about 800 rpm (not to slow and not too fast) it just pushes the slide up a bit as you screw it in. so wind it out a couple of turns and see if the revs drop quicker... but it should stall if the screw is wound right out.

get the bike going and spray wd 40 all over the manifold and carb to airbox joins and see if the revs change (airleak test)

good luck

[kdx 175]

just buy a new one

[80-85 husky]

need to check that's its the actual problem before spending$$ I reckon.

Although its been "rebuilt" it may have leaking engine seals, gaskets who knows... why rebuild then sell for a song? Sum ting wong for sure...

if he could try a good carb first may eliminate these suspects....

[QLD779]

It must be a common problem. My KDX175 does the same thing. Haven't had a chance to look at it yet but the first thing I will do is strip and clean the carbie. Only started it once since I bought it for $600.00

[GMC]

Over revving??
What exactly is that?

Once had a girlfriend who told me her car was revving too high, couldn’t work out what the hell she was on about until I drove it and then found out the clutch was slipping.

Another dopey teenager also told me his car was revving too high, after driving it I found out that the T bar linkage was out of sync and his car was stuck in second gear so yes at 100 Kph it was revving too high.

I can’t foresee the carby causing the need to rebuild the motor unless it was running lean.

Do you mean idling too high? This in itself won’t wear out the motor but it is often a sign that you have an air leak which will cause dramas

‘Revving on’ is usually caused by a leaky base gasket, crank seal or inlet manifold which will cause it to run lean which can lead to an engine rebuild.

My carby has brass showing and replacing the carby is on my list of things to do but it’s not going to cause the engine to stuff up.

[BMC]

my dad said it could be running lean, but as soon as i start it, it would scream and i just dont want to have to rebuild again after what happend ive made sure there were no cracks or leaks in the carby it self, im going to try and tune it all up again,
a question what does everyone that has a kdx 175 run there fuel at like 20:1 ? i was running mine at 28:1 ?

[BMC]

the engine has had new seals and gaskets put in aswell
also with the float in the carby i am missing the spring would that also be a problem?

[crossedup2]

Where are you, what town or city?
Peter B

[80-85 husky]

run a good oil like motul at 32: 1, will be fine for the dx.

You can buy motorex at $30 a litre but run it up to 60:1 for less smoke and cleaner burn.

(I run it at 75:1)

if you don't know what oil it is, 25 or 32: 1 should be fine

[GMC]

There will be a hundred different opinions on oil ratio but you can run from 20:1 to 40:1 without major dramas

i am missing the spring would that also be a problem?

What spring?  The spring on top of the slide?
That will make it scream as the slide will just stick where ever it wants once air is sucking past it.

If your talking about some other spring then I would advise you take the airbox off (3 bolts and a hose clamp) and see that the slide does actually return to the bottom.

Slide not returning to the bottom is pretty much the only thing that will have it screaming

[PEZBerq]

Just because you replaced the seals doesn't mean there are no air leaks. The only way to check is to do a leak test on the motor. See if it holds air pressure for say 5 minutes. Seal the exhaust and intake and pump it up to 5 or 6 psi and see if it will hold. Engine racing when started sounds like may have got an air leak somewhere. When it warms up do the revs drop? This is assuming the carb is set with a sensible idle screw position.