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View Full Version : KR150A engine bad rattle, lock rear wheel



CookMySock
31st January 2010, 11:10
My mate has a low km KR150A. I was told they couldnt start it so I shot around and had a nosey.

After pushing it 50 meters or so I got it running and rode it straight back to the house. It idles perfectly well but has a bad rattle which sounds like th engine's full of marbles. I could stop it and restart it perfectly well.

The exhaust is running very clean, and it looks to me like its getting no oil.

The owner had ridden it earlier and the engine locked and dragged the rear wheel. He let it cool off and limped it home with it repeatedly locking. Yeah I know..

So what are the chances of this just being a piston, and maybe oil pump?

TIA
Steve

Racey Rider
31st January 2010, 12:02
Doesn't take much to take the barrel off and have a look.

If got one here that was sezied by last owner. I honed the bore (not suppost to on these barrels), new piston kit in. It's really noisy motor, but it's still running well over a thousand kms later. (145psi)
Will be getting new bearings and stuff from Thailand shortly though, as they'll neeed changing at some stage.
Racey.

SS90
31st January 2010, 12:30
My mate has a low km KR150A. I was told they couldnt start it so I shot around and had a nosey.

After pushing it 50 meters or so I got it running and rode it straight back to the house. It idles perfectly well but has a bad rattle which sounds like th engine's full of marbles. I could stop it and restart it perfectly well.




The exhaust is running very clean, and it looks to me like its getting no oil.

The owner had ridden it earlier and the engine locked and dragged the rear wheel. He let it cool off and limped it home with it repeatedly locking. Yeah I know..

So what are the chances of this just being a piston, and maybe oil pump?

TIA
Steve

Slim.

From the description you have given, I would have to assume it is the crankshaft that has given up to ghost, (most likely because of an oil pump failure of some kind.

It will need to be pulled down for sure.

CookMySock
31st January 2010, 14:15
Ok thanks fellas. I'll pull the top off and see whats stuffed.

@RR, would you share your parts source in Thailand? PM me or post here at your option.

Steve

oyster
6th February 2010, 10:28
Ok thanks fellas. I'll pull the top off and see whats stuffed.

@RR, would you share your parts source in Thailand? PM me or post here at your option.

Steve
I have a brand new barrel here for the early model one (The one with wire spoked wheels)
PM me if you want it

Racey Rider
7th February 2010, 05:54
Ooo! I'll start the bidding at $1.

$1 , $1 , $1. Do I hear 2?

If you make a list of bits you need, I will price them for you at cost from Thailand, then we share the freight cost when I bring my own bits in.
Racey

CookMySock
7th February 2010, 06:58
That'll be mean az bro. I better pull the top off this thing and see wots up with it then.

Steve

CookMySock
10th February 2010, 12:48
I pulled the cylinder off and the piston and bore (particularly the lower end) is scored to hell, and there's wet grey slimey shit like aluminium powder everywhere. Big end feels loose and dry. Piston top is heavily fouled but not burned as in "lean mixture." No Signs of the engine being hot.

Oil pump stopped? How to test for failed oil pump?

TIA,
Steve

SS90
10th February 2010, 21:41
Erm, I think a "test for a failed oil pump" is not really required.....it's clearly failed!

Find the oil pump, and see if there is actually any oil getting to it. There should be a larger diameter pipe going from the oil tank, to the pump body. Normally, this is a clear pipe.

if it is full, then the supply is most likely ok.

One of the problems with an oil pump, just like a fuel supply can be if someone has replaced the filler cap with a non breathing item, the supply will stop. But if the supply tube is full, and the filler cap original, this is unlikely. Remove the supply hose from the pump end and see how fast the oil dribbles out, if this happens, this end is ok.

Then, refit the hose to the pump.

There will be a silver headed oil pump drain screw on the body of the pump.

Remove this, does oil come out after a few seconds?

Remove the pump body from the housing.

There will be a drive hub that should turn when you kick the engine over, apply a bit of load to the drive hub with your fingers to be sure.

This drive hub is driven off the primary drive via a nylon gear, if the hub does not turn at all, or stops turning when you apply load, the there is every chance the nylon gear is stripped.

This is the most common reason for oil pump failures on machines of this type.

You will need either a new crank, and top end, or, if the price is right, an engineering shop will be able to fit a rod kit, or maybe Oyster in chch can do it if he has time.

BAD DAD
14th February 2010, 13:48
I'll be interested to read how you got on with this one. I just relaced the throttle cable, which also runs the oil pump, on a KR150 and was worried about getting the correct settings of fuel to oil . Seems to run OK at the moment and is definately puffing a bit of smoke, but I have been completely unsuccsessful in finding any technical info about these bikes at all.

CookMySock
14th February 2010, 18:30
@SS90, thank you mate for the detailed information. We would have been in the dark without that.

@BAD DAD, we found a complete replacement engine, many thanks to oyster. Don't know what I will do with this engine, since I seem to have inherited it. I don't really have the cash to rebuild it, so I might pickle it for now and put it into storage. It's got a rattly big end, scored piston, scored cylinder.

Steve