5-7HEAVEN
Well-Known Member
When the day arrives that a Happy Time engine becomes dependable/reliable and lasts for thousands of miles, I will buy one.
How to make a China 2-stroke 48cc / 66cc last forever???
- Thread starter BillMckraken
- Start date
Yes they do vibrateand they really buy break at the last 1300but me personally I guess given to the fact that I know a lot about motors even though this motor is designed to run at higher rpms that's not necessarily true these motors are all about air fuel and must b tuned right unfortunately there is no simple answer for that people live in different areas people way different people miss fuel different and then again some people are just a little slow if I had to recommend you one good upgrade would be an expansion chamber10 that would teach you with a power band is once you feel it do that you will be always trying to make it run at its optimal about
Yes they do vibrateand they really buy break at the last 1300but me personally I guess given to the fact that I know a lot about motors even though this motor is designed to run at higher rpms that's not necessarily true these motors are all about air fuel and must b tuned right unfortunately there is no simple answer for that people live in different areas people way different people miss fuel different and then again some people are just a little slow if I had to recommend you one good upgrade would be an expansion chamber10 that would teach you with a power band is once you feel it do that you will be always trying to make it run at its optimal about
Large Filipino
Member
I've had 2 strokes lasting 10 thousand miles. And I'm sure all it needs is clutch pads.
The biggest things you can do for your engines is not to starve it of oil.
I run a rather rich mixture and it pays me back in extended mileage. The big drawback is black ooze leaking off the engine all the time and dripping off the exhaust.
The other big thing is that I cruise no faster than 15 mph with 12 mph being my average.
My throttle rarely goes past half.
That's about it.
I've seen video's where people have gone 66 mph with aftermarket performance parts like that Fred Head.
That's cool and all but remember that money was poured on that engine in porting and polishing and what not.
But for a basically stock engine,use it as an engine assist and you'll be just fine.
The biggest things you can do for your engines is not to starve it of oil.
I run a rather rich mixture and it pays me back in extended mileage. The big drawback is black ooze leaking off the engine all the time and dripping off the exhaust.
The other big thing is that I cruise no faster than 15 mph with 12 mph being my average.
My throttle rarely goes past half.
That's about it.
I've seen video's where people have gone 66 mph with aftermarket performance parts like that Fred Head.
That's cool and all but remember that money was poured on that engine in porting and polishing and what not.
But for a basically stock engine,use it as an engine assist and you'll be just fine.
J
Joshest
Guest
You can make it more than 2times better.
1. Change main bearings for to skf 6202
2. Upper crank bearing to stihl 028 or 029
3. change pistonwirst stopper rings for malossi race ones.
And
1. use proper 2stroke oil, castrol, motorex or something.
2. set carb more rich. almost 4stroking and keep it.
4. dont dont do heavy mods. only some intake and ex holes bigger or same size( if intake 14,5mm then all way viled same, coners off).
Good work
1. Change main bearings for to skf 6202
2. Upper crank bearing to stihl 028 or 029
3. change pistonwirst stopper rings for malossi race ones.
And
1. use proper 2stroke oil, castrol, motorex or something.
2. set carb more rich. almost 4stroking and keep it.
4. dont dont do heavy mods. only some intake and ex holes bigger or same size( if intake 14,5mm then all way viled same, coners off).
Good work
Still if it's un balance crank then no bearings will fix it I have one that when running makes a scratching sound walk it forward a step and it stops making that sound .I didn't think much of it till 500km later it lost power and has burn marks on the crank . some of these engines are dead men walking from brand new .and some like one I got did 10.000 km at 50 to 60 kmh all day before I broke it .loved that bike lol .but for the price if it does 150 km and that's what you paid then it's not bad one km per dollar the train is $5 per trip
HeadSmess
Well-Known Member
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- May 17, 2010
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changing the crank bearings over willy nilly can sometimes do more harm than good.
theres a little extra numeral on the end, called "clearance"... you want c3 or c4 bearings for crankshafts, they start a little loose, so they get tighter as things start heating up, etc. (this is not the ABEC number, that is simply how ROUND bearings are. 3 being lousy cheap nasty ones, 11 being really expensive...)
run c2 and they WILL seize. run cn, the standard bearing off the shelf, theres a possibility they will seize.
all reputable manufacturers run c4 bearings on cranks. one of the reasons OEM bearings are expensive, besides dealership markups, is that they are produced in small lots for specific purposes. C4 is not a common tolerance...
also an idea to run sealed bearings and pop the inside seal off, 2nd line of defense considering how pathetic the crank seals are in the HT engines...
im not saying not to change the bearings, but to be careful if you DO.
theres a little extra numeral on the end, called "clearance"... you want c3 or c4 bearings for crankshafts, they start a little loose, so they get tighter as things start heating up, etc. (this is not the ABEC number, that is simply how ROUND bearings are. 3 being lousy cheap nasty ones, 11 being really expensive...)
run c2 and they WILL seize. run cn, the standard bearing off the shelf, theres a possibility they will seize.
all reputable manufacturers run c4 bearings on cranks. one of the reasons OEM bearings are expensive, besides dealership markups, is that they are produced in small lots for specific purposes. C4 is not a common tolerance...
also an idea to run sealed bearings and pop the inside seal off, 2nd line of defense considering how pathetic the crank seals are in the HT engines...
im not saying not to change the bearings, but to be careful if you DO.
Steve Best
Well-Known Member
An excellent thread to drag up from the past.
From personal account evidence we have people getting almost zero to thousands of miles from these engines. A common thread is the lower rpm and power demand, the longer life you will receive, barring mechanical or manufacturing defect. Most of the major failures I have heard of have had an aura of performance demand or modification around them. So let's drag up what we know so far:
1) Low power demand and rpm will likely increase the longevity of these engines.
2) High power demand and rpm takes a toll on the life of these engines
3) Modifications tend to introduce a higher possibility of failures because we cannot foresee the consequences of the work done.
This (3) would mean things like damaging the crank or bearings while putting better ones in, grinding not fully cleaned after porting, the lightened pin or piston failing. This takes in Headsmess's suggestion of "If it's not broke, don't touch it" with cranks, especially if you don't know the right bearings to use. As for his advice about using sealed bearngs with inner removed (to solve the seal problem), I'd suggest bearings live longer with a flow of cooling oil by drilling a flow passage from the transfer port. However if this is not done right, you will invoke rule 3). It is a wash which failure is more likely, seals or crank bearing?
Unbalanced cranks are not a problem if the rpm is kept down. Buzz it to no more than 6000rpm like Fabian or LargePilip suggest and crank vibes are not a big problem. Newer Grubee cranks are pretty good, I have good luck with mine to 10,000rpm. That said, the big end bearing is now loose at 2000 miles of that sort ofrthis has been rpm.
Most of this has been said before in:
http://motoredbikes.com/threads/pre...ers-should-do-with-these-2-stroke-kits.11986/
and
http://motoredbikes.com/threads/the-crash-course-for-motoredbike-noobs.10392/
With some bad advice in there too.
I would keep my three rules at the top as a darned good place to start for longevity.
Steve
From personal account evidence we have people getting almost zero to thousands of miles from these engines. A common thread is the lower rpm and power demand, the longer life you will receive, barring mechanical or manufacturing defect. Most of the major failures I have heard of have had an aura of performance demand or modification around them. So let's drag up what we know so far:
1) Low power demand and rpm will likely increase the longevity of these engines.
2) High power demand and rpm takes a toll on the life of these engines
3) Modifications tend to introduce a higher possibility of failures because we cannot foresee the consequences of the work done.
This (3) would mean things like damaging the crank or bearings while putting better ones in, grinding not fully cleaned after porting, the lightened pin or piston failing. This takes in Headsmess's suggestion of "If it's not broke, don't touch it" with cranks, especially if you don't know the right bearings to use. As for his advice about using sealed bearngs with inner removed (to solve the seal problem), I'd suggest bearings live longer with a flow of cooling oil by drilling a flow passage from the transfer port. However if this is not done right, you will invoke rule 3). It is a wash which failure is more likely, seals or crank bearing?
Unbalanced cranks are not a problem if the rpm is kept down. Buzz it to no more than 6000rpm like Fabian or LargePilip suggest and crank vibes are not a big problem. Newer Grubee cranks are pretty good, I have good luck with mine to 10,000rpm. That said, the big end bearing is now loose at 2000 miles of that sort ofrthis has been rpm.
Most of this has been said before in:
http://motoredbikes.com/threads/pre...ers-should-do-with-these-2-stroke-kits.11986/
and
http://motoredbikes.com/threads/the-crash-course-for-motoredbike-noobs.10392/
With some bad advice in there too.
I would keep my three rules at the top as a darned good place to start for longevity.
Steve
J
Joshest
Guest
Something interesting for you guys and girls
25 Hour endurance race with chinese 50cc engine and russian D series. (not alowed hevy mods)
700-800km and bad muddy rainy weather.
Team #89 chinese bike winner
25 Hour endurance race with chinese 50cc engine and russian D series. (not alowed hevy mods)
700-800km and bad muddy rainy weather.
Team #89 chinese bike winner
D
Deleted member 12676
Guest
1. balance the crank
2. put on an aftermarket ignition system that has more retarded ignition timing since the stock timing is too advanced which puts extra stress on the bearings
3. use high quality engine oil
4. use a good foam air filter and clean and oil it often
2. put on an aftermarket ignition system that has more retarded ignition timing since the stock timing is too advanced which puts extra stress on the bearings
3. use high quality engine oil
4. use a good foam air filter and clean and oil it often
