Broken Chain Guide?

[gitsum]

Maybe a few turnpikes might have different rules, but a 150cc engine is legal on interstate highways.

So if your bike has a functional top speed of 65 GPS, does that mean usable?

You are saying that WOT is bad and running 8000 rpm's on a GY6 is bad. Does that mean one or the other or both together are bad? What if running WOT is below 8000 rpm's, is that bad?

What about a lawnmower, weedeater or chainsaw? Should everyone modify the carb or throttle so it can't run WOT or near the redline? What about a 2-stroke engine that has external lubrication and no valves?

I'll ask again. Is WOT bad on every engine, or just a GY6?

What about millions of small Japanese scooters that are rev-limited at top speed? People ride WOT all of the time, how many of these do you see with a prematurely failed engine?

What about events like the Scooter Cannonball? Does this mean the people that compete and finish are just lucky? And yes, there were some GY6 scooters which finished (nothing Chinese).

What about all of the documented trips of people taking small motorcycles or scooters on long trips? To Alaska, to South America, across the United States, around the world, across Canada, and their little machines make it. I think my favorite was across Canada on a Yamaha C3. They seriously overloaded it by more than 100 lbs and then rode it WOT for 3000 miles, two-up. They continued to ride it for a long time afterwards with no ill effects.

I think a quality well built and designed small engine can run at or near WOT for a good percentage of it's lifetime and still have acceptable reliability and longevity. Not all engines are capable of this, and Chinese GY6 engines seem to have a bad reputation for failing when ridden at high speeds.

But there are many Kymco People 150, Kymco Agility 125, Genuine Buddy 125/150, Lance Cali Classic 125/150, SYM Fiddle II 125 and others running their GY6 engines hard all of the time with no worries.

I just can't accept the generalization that running all engines at or near WOT is bad and will break them...

[blueboy5000]

I have already stated my bike's capabilities. I have also stated why running at WOT is bad.

I cannot supplant my own 3 decades of practical experience with your opinion, as it contradicts my own experiences, as well as the opinions of other technicians I have discussed this issue with.

You are free to believe whatever you want, regardless of whether you wish to acknowledge the proven reality that running a gy6 engine a WOT is a very bad plan. But no amount of you believing so is going to rewind time and magically undamage or fix the several gy6 engines I have seen and replaced because their rider thought they could ride in excess of 8k rpms for extended periods

Believe what you want, but simply put, experience and facts disagree with you, ESPECIALLY when you speak of small engines such as lawn mowers and weed-trimmers which are mechanically limited to be impossible to run at dangerous redline rpms.

[gitsum]

Originally Posted by blueboy5000

I have already stated my bike's capabilities. I have also stated why running at WOT is bad.

I cannot supplant my own 3 decades of practical experience with your opinion, as it contradicts my own experiences, as well as the opinions of other technicians I have discussed this issue with.

You are free to believe whatever you want, regardless of whether you wish to acknowledge the proven reality that running a gy6 engine a WOT is a very bad plan. But no amount of you believing so is going to rewind time and magically undamage or fix the several gy6 engines I have seen and replaced because their rider thought they could ride in excess of 8k rpms for extended periods

Believe what you want, but simply put, experience and facts disagree with you, ESPECIALLY when you speak of small engines such as lawn mowers and weed-trimmers which are mechanically limited to be impossible to run at dangerous redline rpms.

OK, now we are getting somewhere.

First of all "several" GY6 engines is a basis for "all"?

Your experience with GY6 engines must be limited because there are quite a few tuned to be drag limited way before hitting 8000 rpm's at top speed. This can also be considered a way to mechanically limit the GY6 engine to a safe speed, just like lawn mowers and weed-trimmers.

Your argument that WOT is bad for a GY6 engine is based on the incorrect assumption that all of them will approach or exceed 8000 rpm's running flat out (there are quite a few Taiwanese or Japanese 50cc GY6 based scooters that can and do exceed 9000 rpm's regularly without engine damage).

In some of your previous posts this was including "all engines" which is even more incorrect.

There is some validity to your idea that WOT can be bad.

My point being that this cannot be generalized and applied to every type of engine (including a GY6). Someone with your experience should know this.

For the record I just want to make it clear there are plenty of scooters that can be pushed at WOT without automatically assuming eminent engine damage.