Keeway RK 125 Running Issues

[bikenut]

As teff says, but its good to have a new gasket or seal for the just in case moments, broken seal/gasket and bike needed for work in the morning, wait 2 weeks for a new part, 10 miles is quite a walk.

What milegae has the bike done and when was the engine oil last changed.

If you remove the rubber breather pipe from the rocker cover, is there any "chuffing" coming out when the engine is at running temp, smoke ??

If it has a kick start, how does the compression feel ?

You could also check the compression pressure but thats for a bit later I feel.

Ign test and valve working clearance check/adjust.
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nuts about bikes

[bikenut]

Hi Dan, hope by now you are progressing with the 125 having checked and adjusted the valve working clearance with no dramas.

A word of warning, particularly with the Skyway brand of chinky 125's.

when they where made in the factory they did not apply any corrosion prevention to the bolts in the engine. More or less every engine bolt was corroded/oxidised/siezed in and they where an absolute pita to remove.

Be warned, but you will have good experience of this type of think as cars suffer from the same, unless you only work on new cars that is.

Water is a good thing to uise for corroded/oxidised/siezed fasteners sometimes, even hot water, or heat and sudden quenching with cold water.

Water seems to wash out the alloy fuzz, its free ( the dam stuff continually falls from the sky here ) and bio degradeable. Believe me it has its uses.
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[Robby]

The strange thing connected by some pipes to the inlet rubber and the exhaust (I think, hard to tell from the pics) should be a little air pump. They use inlet manifold pressure fluctuations to pump air into the exhaust, and make it appear to run a bit cleaner.

They aren't very effective at reducing emissions, they just disguise them a bit. They are prone to failure. Your bike will generally run a bit better if you remove the air valve and blank off its two holes (inlet and exhaust/cylinder head).

HT lead is just generic HT lead, unless yours is moulded into the coil. A new length of HT lead screws into the coil and the plug cap. Cost about £1/metre on ebay.

Valve clearances should be covered in the manual. Expect clearance to be around 0.1mm on both valves, sometimes a bit less for inlet and a bit more for exhaust. Rotate the engine to TDC using the inspection covers on the left hand side of the crank, check the clearances, adjust.

The air filter should not be dripping oil. To clean/reoil it:
1. Dip in petrol, squeeze out, dip, squeeze, repeat until you're happy its clean.
2. Let it dry.
3. Pour some engine oil onto it. Work it into the foam. Squeeze out the excess (hard squeeze). Refit, job done.

Sort out all of these service items and known problems before you try to hunt down any more problems and fix them.

[andy46]

Hi I don't post on here much but I do have a lot of experience with these Chinese bikes. One problem with them is that they are made from inferior materials. When it comes to the carb this means that the ethanol in modern petrol reacts with the metal the carb is made from. the resulting crud usually blocks the idle jet first.

Rebuild kits for these PZ26 are available on ebay for 4 quid BUT my standard solution is a new carb - about a tenner if you can wait for it to come from China or 14 for one from UK stock.

At that price I consider them a service item. If you bike has stood for any length of time with petrol in the carb this is almost certain to be the problem (or one of them)

Check whether yours has a cable choke or a lever (I guess you know) and order the right one. Although they can be swapped with bits from the old carb and this can sometimes save a few quid.

[DJMadness29]

So Sitrep at the moment.

I'm using the bike for work (and thats where all my tools are), so I can only work on it in the hour I get for lunch. So things are taking a little longer than I'd hoped. It currently revs much happier and will get to 50 (55 at a push) at the minute.

I've checked the valve clearances today. According to hondacg125.awardspace.com (which is where I am getting the information for the engine from) the valve clearances should be 0.008mm. Inlet was 0.015mm and exhaust was 0.020mm. These have now been adjusted to the correct setting.

I have also cleaned, adjusted and lubed the chain and my god that made a huge difference. The horrible vibration through the right peg has all but gone. I was surprised that a slightly dry chain (it wasn't stupidly dry) would cause that much vibration. Plus my chain now smells of fake bananas (bananaslip chain lube), didn't realise it was scented until I used it.

I've noticed that the rear sprocket has started to sharkfin so will need to replace it soon. I also noticed today that the Oil level is a little high. I've only got a window to view the oil level and when I serviced it, it was exactly on the max line. Now it looks to be well over. I'm planning on servicing it again tomorrow (has done about 3-400 miles since last serviced but may as well do it again.


So tomorrow is my last day at work until after christmas so the bike will more than likely be put away for the christmas break so won't be getting much work done on it. I'm hoping that I can get a parts order in soon as it takes 4-6 weeks for them to arrive.

Don't think I've done anything else to it at the minute, although I am starting to think that 50 might be its limit. I know the Keyway Superlight will only reach 50 so not sure if its a similar engine.

Thanks all again for your help.

[bikenut]

Cool, so the engine must have been a bit "tappetaby" then.

Start collecting bike tools for home. Take home expected tools needed for the service whilst on xmas break.

The chain needs to be just damp.

If its an o ring chain, then lubing is a bit difficult.

If its an ordinary chain, it can be removed, " boiled" in old engine oil which really helps with cleaning but don't do it in your kitchen!!

Use an old saucepan and camping stove outsidie but be very careful about burns and fires. A chip pan fire ( oil ) can be very serious and any water dropping into hot oil is literally "explosive", so be warned.

The hot oil removes the old lub, dirt and rust !

You will see the chain bubbling with small "squirts" of bubbles and even rust.

Allow to cool, then make sure every link articulates easily and freely, and ever roller rolls the same. I made a vice mounted level surface for the chain, wood long enough so the chain lies on its surface. I also use a strip of wood wide enough to fit between the plates and roll on the rollers.

Wear gloves.

I usually boil it twice and allow to cool enough, then take it out and allow to drip.

When ever link articulates and every roller rolls freely and smoothly, a i use a solvent and clean until the third filling stays clean. I use the old saucepan to clean the chain. When clean I hang the chain and allow to drip and dry.

Next I heat the chain in gear oil and watch the bubbles until they stop. The chain can be adjitate to free the bubbles. You could use linklife or similar.

Allow to cool enough the hang to drip.

An old chain is handy to feed onto the front sprocket when removing the bikes chain, and when refitting the serviced chain.

Wemoto do a good economy ordinary chain, swollow brand from memory, which seem good.

I also lube the front sprocket splines with molygrease.

Remember that the chain needs adjustment and be in correct tension when your weight is on the bike, and that the rear brake mechanism and rear brake light switch will need adjustment after the chain adjustment.

Rear brake working all ok, not stiff, releases properly and the mechanism is in proper "mechanical advantage" ?

You said the oil level seems to have risen ?

Cjheck for fuel in the oil by smell and the ease of which the oil "burns".

Dip the oil, then holding the dip stick with a drop of oil on its end, using a lighter, how easily does it burn ?

If it immediately burns then there is fuel in the oil. Is the dip stick plastic ? Dont burn the dip stick !

If it seems to burn immediately, immediately change the engine oil !!

Always when parked, turn the fuel off.

There may well be a tube on the bottom of the carb, a float chamber drain screw, and overflow. Any signs of the carb overflow overflowing ? ?

How many miles has this bike done ?
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