long warming up period changfa engine required?

[its-st]

Hello,

in the past I had a bad experience with my changfa style 175. After 3 minutes of warming up at low speed, i set the governor handle slowly at rated speed.
Some seconds later I noticed blue exhaust and a very high speed. I only could stop the engine with the decompressor. But it was too late: The piston and connecting rod bearing got stuck. The engine burned the whole lubricating oil. Maybe blown head gasket?

Do you also have the same problems with the engine caused by running it at rated speed when the engine is still cold?

Can you tell me how long do you let your changfa warm up?

And sorry for my bad English, I hope you  can understand me anyway.

Best wishes from Germany,
Michael

[mike90045]

You say the "engine burned the whole lubricating oil"   Does that mean it sucked the crankcase dry ?   You may have broken a ring or somehow, it sucked the crankcase oil into the cylinder or air intake and burned it as fuel. (runaway) ?

[europachris]

I don't warm up my R185 more than a minute or two.  I start it up, run at half throttle for 30 seconds, and then increase to 'generator speed', about 1870 rpm.  I don't load it fully until it's a bit warmed up, but I certainly don't run it for long until I put a load on it.  I'd rather get it up to temp faster as it's more efficient and burns cleaner when it's at operating temperature.

I do have a 'genuine' ChangFa, though.  Some of the ChangFa "style" engines are of pretty poor quality....

Chris

[Doug]

'genuine' ChangFa

I love that.....

[its-st]

You say the "engine burned the whole lubricating oil"   Does that mean it sucked the crankcase dry ?   You may have broken a ring or somehow, it sucked the crankcase oil into the cylinder or air intake and burned it as fuel. (runaway) ?

yes it sucked the crankcase dry and burned it as fuel combined with a runaway. After that I also inspected the piston rings, but they're OK.

Maybe it came through the valve guide of the intake into the combustion chamber? 



Michael

[gpkull]

how much crankcase oil does it hold? even a brief runaway shouldnt suck it dry. it has been said that engines become over fueled and it is indeed the human that usually runs away. either way sorry about the bad luck

[its-st]

Hi,
the engines suck nearly the whole crankcase dry. But there was enough oil to lube the important parts.

The engine was a cheap Jiangdong. Very very poor quality.

There was so MANY casting sand in the crankcase. Everything in it is there just scrap!

I thought about repairing, but there are just 3 parts I can use again: The flywheel, the air cleaner, and the silencer. 

[Doug]

Your the second if memory serves to have that particular brand of engine go Ka-Boom ( the other was a fellow at ( Otherpower )

[its-st]

Last year lots of 7HP Jiangdong engines were sold on ebay for about 170 dollars.
So you mustn't wonder when those cheap engines going Kaboom

But I have now my experience