Broken Chain Guide?

[blueboy5000]

First of all, this is EXACTLY why you DO NOT ride at full-throttle, high RPMs are when 90% of fatal engine problems happen. The gy6 engine does have an oil-pump, but it is very much a non-sump oil system. (yes I know the inlet could be technically called a sump) The engines starve for proper lubrication at high RPMs.

As to what possibly you have blown, you won't know until you disassemble the engine. I'd say it is most likely you dropped a valve or blew an engine bearing or rod/rod pin.

[noahg]

I have disassembled the engine up until the actual block. That's what the attached image is. I'm wondering if that hole is suppose to be there? I doubt it though because I see small metal pieces around it. The piston head, rod, and rings are all fine. The sound that it was making sounded like the rod or the piston head was broken but they are in reletively good shape. Is there a way to take the actual block apart without destroying everything? Sometimes I have to go full throttle when my scooters top speed is 45mph... I'm just hoping I can fix it since I've already put like 150-200$ into fixing it already. Thanks for the reply though.

[gitsum]

Originally Posted by blueboy5000

First of all, this is EXACTLY why you DO NOT ride at full-throttle, high RPMs are when 90% of fatal engine problems happen.

Is this specific to GY6 engines or all engines? Is this more likely to happen on a Chinese engine?

Do you have any data to back these numbers up?

I don't have any data, so I'll give my opinion strictly as a guess and from personal experience.

Neglect is probably the number one cause of engine failure. Running low or out of oil, running on dirty and broken down oil, running lean because of a dirty carb/clogged air filter or an air leak, valves out of adjustment etc, will break an engine faster than anything else including running WOT.

I ran my Honda Elite 110, CPI Oliver City 50, SYM DD50, SYM HD200, Yamaha C3, and Tomos Nitro 150 at WOT for extended periods repeatedly with no engine problems.

I noticed in your signature you state the top speed of your scooter is 65 mph GPS verified. What good is that if you are unable or unwilling to use it?

I tentatively question that you may be saying running a Chinese scooter at WOT is not recommended?

[noahg]

Thanks for joining in. I know for a fact I took good care of the engine while I've had it. I'm jot sure about the previous owner but I changed the oil right when I got it, even the brake fluid because the brakes werent working like they should. I cleaned the carb the other day and it was spotless. All passageways were clear and it wasn't dirty at the bottom of the float. The engine would give out sometimes before this as stated before.

[blueboy5000]

Originally Posted by gitsum

Is this specific to GY6 engines or all engines? Is this more likely to happen on a Chinese engine?

Do you have any data to back these numbers up?

I don't have any data, so I'll give my opinion strictly as a guess and from personal experience.

Neglect is probably the number one cause of engine failure. Running low or out of oil, running on dirty and broken down oil, running lean because of a dirty carb/clogged air filter or an air leak, valves out of adjustment etc, will break an engine faster than anything else including running WOT.

I ran my Honda Elite 110, CPI Oliver City 50, SYM DD50, SYM HD200, Yamaha C3, and Tomos Nitro 150 at WOT for extended periods repeatedly with no engine problems.

I noticed in your signature you state the top speed of your scooter is 65 mph GPS verified. What good is that if you are unable or unwilling to use it?

I tentatively question that you may be saying running a Chinese scooter at WOT is not recommended?

17 years as professional automotive technician, and 25 years as a motorcyclist have taught me all about how excessive WOT riding can drop valves, blow head gaskets, seize oil-pumps ect.

Working on my clubs's fleet of 12 current scooters has re-affirmed all of this, as two of my riders INSIST WOT is cool, and routinely waste gy6 engines (not that they care, a whole engine is only $500 or less)

My bike has FUNCTIONAL top-speed of 65 mph, so what I should be saying is "I have ridden my bike at a maximum speed of 65mph gps verified", I hit 65 at about 7800 to 8000 rpm on FLATS, my bike redlines at 8500, and has a MAX rpm of aprox. 10,500 (or whatever I set it to with the adjustable CDI, the CDI limits RPMS to 12,500, I have it SET to 10,500)

As to "what good is it": What good is riding at 65+mph? Why do I need to ride my bike at a faster speed? 150cc are NATIONALLY BANNED from limited access highways in the USA. I see NO logic in running my bike in the higher RPMS, and risking inner damage from OIL STARVATION.

I simply do not understand this logic of people claiming that engines are supposed to run at 100% of their power band routinely. I don't buy this as it is illogical. That's like claiming that because you can run at full-speed, you should never walk. I mean running is cool and all, but find me a doctor who says you should run constantly. You won't. He'd say not to run everywhere as fast as you can as it is BAD for you to do so.

As to my estimate that most engine death occurs at high RPMs, I invite you to ask ANY engine building shop about this.