non running kh 125

[johnkerr]

Hi new to the bike scene & recently bought a 1980 kawasaki kh 125, having restored many car in my time thought that this wouldnt be a problem however i cant get the thing to run.
cleaned carb checked points, getting good spark,changed fuel previous keeper had put oil on the fueltank not the oil tank.
was told by previous keeper that it needed a new carb but i cant see why if its all clean and engine is getting fuel as plug is usually kinda wet. it will start but wont run for any length of time.
tryed to buy a new carb but having problems sourcing one.
any advice would be greatly appreciated as was hoping to restore the old girl and use it for my cbt then get some experience and then get bigger bike

[P.addy]

try slightly retarding the ignition. My kh ran smooth as silk and was far too retarded.
If you retard it and start with choke open and 1/4 throttle...see how long you can run it for.. make sure the 2 stroke oil pump is still working and connected fine!

[SillyMe]

I have read on other forums relating to the same issue that the carbs on these can give a little trouble in terms of tuning and cleaning.

Turn the idle screw clockwise to increase idle speed, if no good sounds as though the idle jet an main jet will need sorting.

dismantle it and clean all jets and passages. Only use carb cleaner in aerosol form. Word of warning, NEVER attempt to clean the jets with any type of wire, as this will enlarge the soft brass alloy, thus causing many further problems. Lastly, check for any air leaks, such as loose air intake duct, leaking RH engine cover gasket etc and also check the air filter.
____________________
Once made equal to man, woman becomes his superior.
The man who says "I may be wrong, but -" does not believe there can be any such possibility
Owned and rode: Honda 100H, Honda MBX 125, Kawasaki AR 125, Suzuki RG 125 Pepsi, Honda NSR125 RK, Honda NRS 125 race bike, Suzuki GSXR 400 Bandit, Aprilia RS 125 O2, Honda CG125, Kawasaki KMX 125, Aprilia RS 125 O6, Suzuki XT225 and now Honda XR 400. ( A few scooters and other dead beats in between)

[G and J recovery]

these were prone to slight cracks in the rings,

hense it running a bit then the fuel going down the cylinder,

other than that they were prone to the tank tap mesh being block with rust from the tank, and not allowing enough fuel through once choke off from starting
i have done alot of these in the past,

the carb float flange were metal and use to bend alot so needed reseting so it shuts the fuel of

just a stab in the dark for you,

if its been standing a while try cutting a mil of the ht leat as they corrode were it screw on the plug cap

hope this helps
____________________
glen

[johnkerr]

cheers guys ive tryed cleaning out with fluid then blowing out the jets screwing in the idle screw does nothing, checked the fuel trap and cleaned mesh out also flushed out tank.
it does seem to be getting fuel as plug is always wet will give the timing a check an hope that works or then i`ll check the rings although it does seem to have good compression but will try anything
thought that this being quite a popular bike that spares would be easy to get a hold of, apparently not.
still soldier on
cheers

[SillyMe]

Found a few bits and bats for you pal!
https://shop.ebay.co.uk/?_from=R40&_trksid=m570&_nkw=kawasaki+kh+125+carburetor&_sacat=See-All-Categories


https://shop.ebay.co.uk/i.html?_kw=1980&_kw=kawasaki&_kw=125

https://shop.ebay.co.uk/i.html?_kw=1980&_kw=kawasaki&_kw=kh
____________________
Once made equal to man, woman becomes his superior.
The man who says "I may be wrong, but -" does not believe there can be any such possibility
Owned and rode: Honda 100H, Honda MBX 125, Kawasaki AR 125, Suzuki RG 125 Pepsi, Honda NSR125 RK, Honda NRS 125 race bike, Suzuki GSXR 400 Bandit, Aprilia RS 125 O2, Honda CG125, Kawasaki KMX 125, Aprilia RS 125 O6, Suzuki XT225 and now Honda XR 400. ( A few scooters and other dead beats in between)

[johnkerr]

[stinkwheel]

Have you put a new sparkplug in it?

If not, do so. Just because a 2-stroke appears to have a spark with the plug on the head, it doesn't necessarily mean it has a spark with it in the engine, nor that it is a "good" spark.

First port of call with any running problem on a stroker is to replace the plug. I suspect you'll find there is even a clip to hold a spare sparkplug either under the saddle or sidepanel for just such an eventuality.

My Dads KH350 triple has factory fitted storage clips for TWO spare sets of sparkplugs under the saddle (6 in total).
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[johnkerr]

[stinkwheel]

In which case, I'd still be hell of a suspicious that it isn't getting enough fuel given the symptoms of running for a short while then conking out.

If it restarts again after a short wait, I'd be extra, super suspicious that either the fuel flow from the tap is poor, the needle valve is blocked or the float height is too low.

Another thing that is always worth considering on a 2-stroke, especially one that's older and has been off the road for a while is shot crank seals. These give every impression of being a carburettion problem. It would usually be the left one (the right one is immersed in gearbox oil which tends to seal it even if it's a bit duff, if one is gone, replace both anyway).

Symptoms of a duff crank seal are simlar to those of running super lean or without fuel altogether. The engine would have good compression but little or no suction through the carb as it is drawing air straight into the crankcase past the dodgy seal rather than through the carb. Try removing the airbox rubber and putting your hand over the end of the carb with the engine running/being kicked over, you should notice significant suction (the engine will also start to die as you do this).

Lack of vacuum at the carb, consider replacing the crank seals. On most bikes, you can bodge the old ones out by removing the circlip and extracting the old ones out by screwing a couple of self-tappers into them and pulling hard. Drive the new ones on using a big, deep socket or a bit of alloy billet turned down to suit, being very careful not to damage the inside lip of the seal (make sure there is no rust or burring on the bit of crankshaft you slide it over). You'd need to pull the flywheel and primary drive sprocket and remove any woodroffe keys to get at them but it's easier than splitting the engine.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[johnkerr]

[yanto]

some times cleaning the carbs isnt enough and they need sonic cleaning
ether send them away and pay them to do it
or go to maplins and buy a sonic jewellery cleaner and the cleaning stuff
thats what i done and have done about a hundred sets of carbs

[stinkwheel]

You might be interested to hear that they do actually still make KH125s in South America. As I recall, they are marketed as a GTO.

They don't officially import them into the UK but you might find parts are still available to order through Kawasaki if you order them by part number rather than by what they are.

I find dealers tend to get humpty and unhelpful if you approach them for parts for old bikes whereas if you go in and say "Can you get me part No:1234-5678.", they just plug it into their system and see what it spits out.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[Blue_SV650S]

Is it piston ported or reed? ... I'd b inspecting the reeds ...
____________________
The purpose of life is to fight maturity.

[evoboy]

[Blue_SV650S]

[stevo as b4]

It is disc valve inducted as are all single cylinder KH models. The disc valve could be scored or not sealing very well or the disc valve cover backing material may be damaged or flaking off too.

Check the compression with a guage against what the manual says. It would be good to have over 100psi as a minimum figure though!