When I was young 13 I built a kings on a Shwinn n did it by instruction manual. Switched to 50:1 when it was 4 tanks down and used some mc pre that claimed 100:1 for most high end Japanese 2 strokes . Got that motor up too 33 on the flat after I ****ed up and drilled 2 holes in my muffler cap ever since then it was weak. When I was 20 in SC I built one I got off that guy who has or had a shop downtown there and so did my buddy we were not opening it up right off the but there was a dirt road Hill real steep off his driveway by the 3rd time we road I opened that thing up and still had too pedal, the hill started right there on the driveway and was steeper than most in SF but I got that bike to go 42 clocked by a cop with the pocket bike expansion exhaust it was lacking in torque but due to the exhaust. Now I got a new build a stinger motor with the straight plug and aluminum no paint like it always had. The only difference Is it's 50t while the others were 44 the 1st was the old hole sprocket. Now what pre did u use, how did u break in and does the plug make any difference I never had a bad HT plug.
How do You break in your ht motor?
- Thread starter cashark
- Start date
You'll get a lot of different answers for that question because everyone has their own methods... Here's how I do it...
With a new engine I'll start it and run it for about 10 minutes but constantly blipping the throttle not letting it run at any specific rpm, just blipping the throttle keeping it between about 2500 to 3500 rpm with the clutch in and no load on the engine. After the engine is warmed up for about 10 to 15 minutes I'll shut it down and let it cool all the way which takes about 30 minutes. this step will loosen up the engine and gets it ready to ride on.
After the engine is cooled all the way down it's time to take it for a short ride... again under 30 minutes of run time. This ride I'll go slow but run it from 5 to 10 mph trying not to hold any certain speed, just run it from about 5 mph and crack the throttle about half way then let it slow back down etc... Bringthe bike back home and let it cool all the way down again.
After it's cooled down I'll check the torque on the head nuts by backing off the torque and retorquing each nut one at a time, then I'll check for anything that may have worked loose like header bolts, manifold bolts, chain tensioner... just check everything you can think of...
Next run will also be short (less than 30 minutes) and similar to the previous but giving it short bursts up to about 3/4 throttle and running it around 15 mph but let it burst up to 20 or so. Let it cool after about 20 to 30 minutes, then it can be ridden a few more times like this.
After the first tank of fuel you can start giving it more but keep your full throttle play to short bursts, no full speed runs but cruise at different throttle positions, you'll start to feel the engine become stronger and faster during this time.
After the second tank, this is when you can start opening it up and seeing what it can do, it's still not fully broken in but it's safe to play with it more. This is also a good time to check your head bolt torques and check that nothing else worked it's way loose, by this time everything should stay put and shouldn't work it's way loose, but still worth checking.
The engine will get a little stronger after a few more tanks but it's safe after about the 3rd tank to ride it however you want.
With a new engine I'll start it and run it for about 10 minutes but constantly blipping the throttle not letting it run at any specific rpm, just blipping the throttle keeping it between about 2500 to 3500 rpm with the clutch in and no load on the engine. After the engine is warmed up for about 10 to 15 minutes I'll shut it down and let it cool all the way which takes about 30 minutes. this step will loosen up the engine and gets it ready to ride on.
After the engine is cooled all the way down it's time to take it for a short ride... again under 30 minutes of run time. This ride I'll go slow but run it from 5 to 10 mph trying not to hold any certain speed, just run it from about 5 mph and crack the throttle about half way then let it slow back down etc... Bringthe bike back home and let it cool all the way down again.
After it's cooled down I'll check the torque on the head nuts by backing off the torque and retorquing each nut one at a time, then I'll check for anything that may have worked loose like header bolts, manifold bolts, chain tensioner... just check everything you can think of...
Next run will also be short (less than 30 minutes) and similar to the previous but giving it short bursts up to about 3/4 throttle and running it around 15 mph but let it burst up to 20 or so. Let it cool after about 20 to 30 minutes, then it can be ridden a few more times like this.
After the first tank of fuel you can start giving it more but keep your full throttle play to short bursts, no full speed runs but cruise at different throttle positions, you'll start to feel the engine become stronger and faster during this time.
After the second tank, this is when you can start opening it up and seeing what it can do, it's still not fully broken in but it's safe to play with it more. This is also a good time to check your head bolt torques and check that nothing else worked it's way loose, by this time everything should stay put and shouldn't work it's way loose, but still worth checking.
The engine will get a little stronger after a few more tanks but it's safe after about the 3rd tank to ride it however you want.
Like Davezilla said, there's so many answers to this question. I mean, it's the proverbial can of worms in a necromancer's subject.
When it comes to chinagirls there far more ways _not_ to break in an engine than there are so-called "proper ways" to break one in.
Each one is like an individual human being in a way, but with a much shorter lifespan. What works for one will not work for another, every one likes to be rubbed a certain way. Many will blow up before you figure that out or do it just as you think you have it figured; the lucky ones will love ya long time.
It's all a lottery. IMHO, the best thing you can do is treat it with respect and don't get greedy with power and/or speed. The chinagirl is based on a design over 70 years old and was not designed for you peel out, do wheelies, and do 40+ on highways. No, it's really not.
Most important: don't "fix" it if it aint broke.
When it comes to chinagirls there far more ways _not_ to break in an engine than there are so-called "proper ways" to break one in.
Each one is like an individual human being in a way, but with a much shorter lifespan. What works for one will not work for another, every one likes to be rubbed a certain way. Many will blow up before you figure that out or do it just as you think you have it figured; the lucky ones will love ya long time.
It's all a lottery. IMHO, the best thing you can do is treat it with respect and don't get greedy with power and/or speed. The chinagirl is based on a design over 70 years old and was not designed for you peel out, do wheelies, and do 40+ on highways. No, it's really not.
Most important: don't "fix" it if it aint broke.
Yea I really wanted to hear different opinions one the process I know by the 6th tank it's pretty much fully broke in and the plug I got a Stinger from a 10 or 15 pack my buddy got so it all depends he said.and a neighbor confirmed that.the black slant heads are less powerful so he rides a straight plug alum and saved me one. I totally understand when u say the re just basic motors I really just want to have a lot of torque the hills are crazy here if u see the pic forget the duct tape it's comin off besides where it meets the two muffler clamps and plate with a 3 hole drill in ur frame rig mounted on th 1/16 steel plate should I get a B5HS plug or does it not really matter ?
If you want the best torque, gear it accordingly! Gears make the biggest difference. Keep in mind, the chinagirl oils itself under load.
This means when going downhill, the best thing you can do is pull the clutch lever in and coast. Do not use engine braking!
My best hillclimber 2-stroke used the stock 44T gearing and pedal gearing set up for max pedal torque at 15MPH.
The engine was stock aside from cleaned-up ports, made max torque at about 15MPH itself. I climbed some very steep hills with it without issue.
As for plug, in the Bay I'd recommend a B6HS all-around. A B7HS should work fine too. From my exp, a B5 is more of a winter plug.
This means when going downhill, the best thing you can do is pull the clutch lever in and coast. Do not use engine braking!
My best hillclimber 2-stroke used the stock 44T gearing and pedal gearing set up for max pedal torque at 15MPH.
The engine was stock aside from cleaned-up ports, made max torque at about 15MPH itself. I climbed some very steep hills with it without issue.
As for plug, in the Bay I'd recommend a B6HS all-around. A B7HS should work fine too. From my exp, a B5 is more of a winter plug.
Re. Break in.
It would be irresponsible of me to tell people to break a motor in the way I do.
But anyway I've built a few different types of motors over the years, but I liken these engines to an old air cooled V.W. engine. Whilst I was studying engineering as a 19/20 year old I did a while as a V.W. mechanic for a place called Custom Off Road.
And these guys built some really fast off roaders, they use to take home trophies everywhere they went.
Now these motors got stripped down before a race, and received a new set of piston and rings.
When I asked how they ran these motors in with the race tomorrow?
They told me "As we put it on the trailer!"
I was told, To break a motor in, you got to get it hot, you got to use the whole rev range, and you want to do it with out putting the engine through undue labor.
Now a side note to this is the more revs you use on that motor the shorter its life is going to be. For every 1000 revs more that you wring out of that motor, halve it's life span!
Important thing though, have your mix either correct or a little rich.
Now when people run a motor in at 16-1 or something stupid like that, the more oil, the less fuel, the leaner your motor is running!
So, up here in the tropics is hard on two stroke motors, the humidity and the heat require a little more oil, So for breakin I put one tank of 25-1 through my motor. then switch to 40-1.
In a more suited climate make that 30-1 for break in and 50-1 after break in. And then if you feel inclined 100-1 of the right stuff.
Now all my motors are stripped, cleaned, checked, and set up with patience, experience and care.
This is one of the reasons why I feel that it would be irresponsible for me to recommend a "quick run in", as, if the chances are your motor wasn't?
Therefore there could be any manner of poor workmanship, and on stripping these motors you can pretty much guarantee to find something a miss, that needs a little more time to bed in.
Something that hasn't been lubed properly, and/or something that was dirty.
This may not go down well with 9000 RPM straight off the bat.
Now my attitude is pistons, rings, gaskets ect are cheap, the motors are easy to work on, and I don't mind having to replace these things every now and again to maintain performance.
In fact it gives me the opportunity to tweak it some time and inspect bearings ect, and lessen the chance of major catastrophe. This is not necessarily so if you do not know what your doing!
And this is it, if you don't know what your doing, be nice to the little motor whilst you run her in.
If you trust your motor, and you don't mind giving it a strip/rebuild every so often, give it heaps.
It would be irresponsible of me to tell people to break a motor in the way I do.
But anyway I've built a few different types of motors over the years, but I liken these engines to an old air cooled V.W. engine. Whilst I was studying engineering as a 19/20 year old I did a while as a V.W. mechanic for a place called Custom Off Road.
And these guys built some really fast off roaders, they use to take home trophies everywhere they went.
Now these motors got stripped down before a race, and received a new set of piston and rings.
When I asked how they ran these motors in with the race tomorrow?
They told me "As we put it on the trailer!"
I was told, To break a motor in, you got to get it hot, you got to use the whole rev range, and you want to do it with out putting the engine through undue labor.
Now a side note to this is the more revs you use on that motor the shorter its life is going to be. For every 1000 revs more that you wring out of that motor, halve it's life span!
Important thing though, have your mix either correct or a little rich.
Now when people run a motor in at 16-1 or something stupid like that, the more oil, the less fuel, the leaner your motor is running!
So, up here in the tropics is hard on two stroke motors, the humidity and the heat require a little more oil, So for breakin I put one tank of 25-1 through my motor. then switch to 40-1.
In a more suited climate make that 30-1 for break in and 50-1 after break in. And then if you feel inclined 100-1 of the right stuff.
Now all my motors are stripped, cleaned, checked, and set up with patience, experience and care.
This is one of the reasons why I feel that it would be irresponsible for me to recommend a "quick run in", as, if the chances are your motor wasn't?
Therefore there could be any manner of poor workmanship, and on stripping these motors you can pretty much guarantee to find something a miss, that needs a little more time to bed in.
Something that hasn't been lubed properly, and/or something that was dirty.
This may not go down well with 9000 RPM straight off the bat.
Now my attitude is pistons, rings, gaskets ect are cheap, the motors are easy to work on, and I don't mind having to replace these things every now and again to maintain performance.
In fact it gives me the opportunity to tweak it some time and inspect bearings ect, and lessen the chance of major catastrophe. This is not necessarily so if you do not know what your doing!
And this is it, if you don't know what your doing, be nice to the little motor whilst you run her in.
If you trust your motor, and you don't mind giving it a strip/rebuild every so often, give it heaps.
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I've also heard of some who start it up, go easy on it for a few minutes then ride it like they stole it, and I've used that method before but I'm not going to recommend it... it's not uncommon for me either to pull the jug, replace the rings and re hone because I wanted to at too hard too soon... rings are cheap and the jug can take a quick hone just enough to break the glaze quite a few times before it gets too loose to run...
Of course, that's not what I recommend for someone who wants their engine to last...
Of course, that's not what I recommend for someone who wants their engine to last...
The engine needs to see a load. No load means that the rings just simply chatter around in the cylinder bore too much . Making a sloppy break in from every artical I have read on the subject that made sense to me. The cyclinder seals better when rings have been seated the best.
On a new motor when I know the carb is tuned right. I then simply get on the machine and ride it. Out side my house is a good 5 mile run ''up hill'' That is where I go every time. Nice and steady. I do mix the trhottle up a little bit. Yet I am after sealing the rings at this point.
This in turn trains the rings on to there proper even running, well sealing path.
On a new motor when I know the carb is tuned right. I then simply get on the machine and ride it. Out side my house is a good 5 mile run ''up hill'' That is where I go every time. Nice and steady. I do mix the trhottle up a little bit. Yet I am after sealing the rings at this point.
This in turn trains the rings on to there proper even running, well sealing path.
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I fire mine up, run them down the road a ways watching and listening for any signs of a problem with chain or mounting, make sure brakes on bike are all working properly and that everything I can see hear or feel seems to be in order.
Now after about 15-20 miles and all looks good I open it up. Real good once or twice to see what the tune on the carb seems like and then I cruise it at a good speed just a little under wide open for a while then back home and let it cool for a little while and I pull the plug to check its color, by now I already know if Im on the rich side by ridiing it those few miles and the plug color will comfirm what my carb tune is like.
Ill make adjustments based on what I know it needs from experience on other china girls I have and then I pretty much run the dog out of it just the way I plan to do for the life of the engine and it will run a little better and better normally until it get 300-400 miles on it and by then its normally settlex in nice.
Map
Now after about 15-20 miles and all looks good I open it up. Real good once or twice to see what the tune on the carb seems like and then I cruise it at a good speed just a little under wide open for a while then back home and let it cool for a little while and I pull the plug to check its color, by now I already know if Im on the rich side by ridiing it those few miles and the plug color will comfirm what my carb tune is like.
Ill make adjustments based on what I know it needs from experience on other china girls I have and then I pretty much run the dog out of it just the way I plan to do for the life of the engine and it will run a little better and better normally until it get 300-400 miles on it and by then its normally settlex in nice.
Map