Life Expectancy for a Good Engine

[xlite]

gear box replaced bearing at around 5,800 mi

So.. as I said no case of a 4 stroke ever reaching 14k or even half that.

Many 2 strokes got there and beyond. You appear to be one of the few cases of a chinese 4 stroke kit getting thousands of miles. The few locals that have one never even got hundreds before the gearbox failed.

 

[chrisme]

The only real bad problem I've had with the HT engine is the carb. It is a POS. I have been running the engine WOT for over 3k miles, and it is holding up fine though. Some aren't so lucky. Bu it is still a crappy quality engine. Whether it is holding up or not. It just isn't high quality.

 

[bairdco]

...replacing all the bolts so you can overtorq them and not strip the threads...have ya ever thought the threads were made to have a fail point so you didn't damage things? Retorq the bolts every so often makes stress failure eventually even if torqed correctly...

... I can also remember asking if overpowering the motor kicking in peddlin for an extra boost of speed hurt the motor with several people saying it didn't hurt...it does over revving any engine is not a good thing.

just wanted to throw some change your way, george (my two cents worth.)

i don't think the chinese had "shear loads" in mind when they built these. i can't think of one scenario where i'd want the threads to strip. seems to me, the chinese "fail point" is as soon as you pick up a screwdriver.

i replace all the bolts with grade 8 allen head socket caps, because the stock hardware is junk. for one, i dunno what kind of screwdrivers the chinese have, but out of the dozen or so i have, none of them fit the slots properly, and strip out the screws. in time, the cheap hardware works itself into the cheap alloy, and i don't want to drill and tap a new hole just because the slots of the screw can't take the pressure of a snap-on screwdriver.

a bolt with a good quality allen head, applied with anti-seize, will almost always come back out with no problems at all.

and they look way cooler.

also, i don't retorque anything after the initial break in. i "heat cycle" the head bolts, exhaust and intake a few times, then leave them alone. motor mounts i check after the first ride. once in a while something looks loose, so i'll check it. but if it doesn't turn, i don't force it.

and i never use loctite. never needed to, and i've beat that argument to death elsewhere.

as far as pedaling with the motor on, i do it to maintain speed, and to build up speed to take pressure off the motor. if it's already winding out, i probably can't pedal that fast anyway.

and finally, i'm 40. i'm not done pushing engines to the limit yet. if i wanted to go slow, i'd get a rascal power chair .

 

[nsideus]

So.. as I said no case of a 4 stroke ever reaching 14k or even half that.

Many 2 strokes got there and beyond. You appear to be one of the few cases of a chinese 4 stroke kit getting thousands of miles. The few locals that have one never even got hundreds before the gearbox failed.

I would like to know what you replaced, repaired, bought new to make 14k with a happy time.
No other 2 stroke owners are making the 14k claim. You appear to be the only case.
Grubee is the most reliable, but one needs to know how to make it last.
Aren't we talking about 4 strokes engines in this thread?

 

[george_n_texas]

No amount of fancy bolts or anything else is gonna make my ugly carcas look cool on a bicycle LOL. I know snap-on makes great tools but geez a screwdriver snappin to fit is something I never had on my shoppin list. I do think over torqing a bolt on an aluminum block is an issue I liked Azbill's advice for torq to use 1/4 inch drive and hold it close to socket end that's my torq spec seems to work for me but then again I know what 10 lbs of torq generally feels like after stripping a transmission pan threads thru my lack of experience. You are right we all feel like a kid on these things at an amusement park and I am sure everyone pushes these toys past what they were designed to do. It must be that great air in Orange county what keeps ya from bein able to peddle faster than that engine can pull.

 

[xlite]

I would like to know what you replaced, repaired, bought new to make 14k with a happy time.
No other 2 stroke owners are making the 14k claim. You appear to be the only case.
Grubee is the most reliable, but one needs to know how to make it last.
Aren't we talking about 4 strokes engines in this thread?

I replaced the spark plug a few times and one chain. Several problems with mounting bolts until I learned about threadlocker and not tightening too much. No problems with gearbox, clutch, or engine (except loss of compression). At least two of my other bikes now have over 5k. Several HT users have posted 5000-10000 mile lifetime in the past week alone. You asked.

Sometimes reality does not always comply with theory or what we wish were true.

 

[Dan]

I have both ChinaGirls and one Honda 4 smoker. Really enjoy them both but as said earlier in this thread, the 4 strokes get far better mileage, better longevity and has a lil more "umph" Also 4 times the price, not as sexy (unless modded like Hough's masterpiece)

But back to the question, a really good long while. Now will you kids play nice?

(I would not offer an opinion on either if I didn't own both. Just didn't want any one thinking I had read some thing, some where and now am espousing it as gospel)

Think we lost CaerGrim

 

[Riding Rich]

I think alot has to do with the diverse terrain these are rode in.
Some sandy / Some Salty / Some hot / Some cold.
You name it.
So obviously these conditions have alot to do with it.

Now i have pushed my poor little Grubee wayyyyy beyond and back again.
The cylinder and piston are a little skuffed up.
The piston pin needle bearing needed changed after 2000 mi and my bottom crank needle bearings are ready to croak.

But i run this motor at 6000 / 8000 rpm.

So my soloution to longevity.

Found a motor with crowded needle roller bearing on the big end.
Sthil chainsaw bearing on the Piston Pin. ( rated for 13000 rpm.)

Good bearings will help keep the scuffing down.

Also the new PK i bought i totally tore down and cleaned so well you could eat off of it.
Put it all back together with the better bearings and everything lubed up very well for the first run.

I expect this one will take my abuse and still last long.

I plan to figure out a Preventitive Maint. Plan.
Fix it before it breaks.
If you catch it before it goes crunch things are cheap and easy to fix.

 

[Dan]

Did you get pics Rich? Would make a great thread with or with out them. Please keep posting. Sounds like a great idea.

 

[bairdco]

...It must be that great air in Orange county what keeps ya from bein able to peddle faster than that engine can pull.

my bike's in the 35 to 40mph range now. if i could actually pedal a 1950's beach cruiser that fast, i'd probably try out for the olympics...(ha ha ha smiley face)

and in orange county, i can run my bike leaner, 'cause the air filter will suck up all the other motorists' oily exhaust

 

[george_n_texas]

my bike's in the 35 to 40mph range now. if i could actually pedal a 1950's beach cruiser that fast, i'd probably try out for the olympics...(ha ha ha smiley face)

and in orange county, i can run my bike leaner, 'cause the air filter will suck up all the other motorists' oily exhaust

That splains alot a single speed bike...mine's a 12 speed mountain bike. I been to LA many times I like SanBernadino but man hats off to you dealing with that traffic. I used to deliver to the Pep Boys in San Bernadino.

 

[happyvalley]

I tally hours with a tach and not miles. I have one personnal bike with a R/S EHO35 with over 500 hours. I do baby my bikes with a careful run-in, frequent oil changes and not a lot of heavy, WOT running.

I'd guess Honda mini's to be comparable.

A while back I bought up a bunch of new Robin engines from a concrete contractor on close-out.
They went out of business with the economic downtown but were using them on powered concrete screeds. Their equipment guy said they ran the engines for 600-700 hours and then scheduled a swap out for new rather than rebuild 'cause it was cheaper. I bought new in box engines but did see some of their used stuff and it was hard run with what I'd bet was marginal maintenance.

 

[nsideus]

Several HT users have posted 5000-10000 mile lifetime in the past week alone. You asked.QUOTE]

Yep no other 2 stroke owners are making the 14k. You told

 

[Dan]

I tally hours with a tach and not miles. I have one personnal bike with a R/S EHO35 with over 500 hours. I do baby my bikes with a careful run-in, frequent oil changes and not a lot of heavy, WOT running.

I'd guess Honda mini's to be comparable.

A while back I bought up a bunch of new Robin engines from a concrete contractor on close-out.
They went out of business with the economic downtown but were using them on powered concrete screeds. Their equipment guy said they ran the engines for 600-700 hours and then scheduled a swap out for new rather than rebuild 'cause it was cheaper. I bought new in box engines but did see some of their used stuff and it was hard run with what I'd bet was marginal maintenance.

Hey HV. long time no type.

I (according to speedo) average 15.7 MPH. At 500 hrs, that would be 7850 miles. I am a little heavy on the throttle though

 

[happyvalley]

Hey HV. long time no type.

I (according to speedo) average 15.7 MPH. At 500 hrs, that would be 7850 miles. I am a little heavy on the throttle though

How'rya Dan
Yup if I had to guess my avg. speed I'd say 15 mph and figured somewhere 'tween 7 and 8K.
Runs great and she should have more in her.

 

[motor_head]

If your concerned about the environment better you direct your bleeding heart against all the vehicles powered by diesel fuel,

diesels are ALOT more more efficient than gas

 

[Riding Rich]

Yes DAN

I have lots of pics and good stuff to post.
Allready have posted some of it.
Look for PK80-J teardown.

I'll be posting about porting later.

 

[Dan]

diesels are ALOT more more efficient than gas

But what is their life expectancy? (Kidding, kidding. Put the wrench down! lol)

Didn't know that about diesel MH. In looking it up, seems there is a controversy on the subject.

is diesel better for the environment - Google Search

Can't we all just get along? Snork

 

[Dan]

Yes DAN

I have lots of pics and good stuff to post.
Allready have posted some of it.
Look for PK80-J teardown.

I'll be posting about porting later.

Just read it Rich. Nicly done!


http://motorbicycling.com/f4/pk80-j-limited-edition-slant-head-13117.html

 

[Riding Rich]

Thanks lots more to come.

I wonder what the life of this motor will be.