As I struggled with a non functioning small 2 stroke engine on my leaf blower ( suddenly after 3 or 4 years of good service), and trying everything I could think of, I stumbled into a video about a unit with many of the same history/repair points as my unit. That engine was repaired by tightening of loose bolts, cylinder to block, which was permitting air leaks. I checked my engine - rock solid but while there I chanced to remove the blind end plastic crankcase cover. Nasty hole in this cover so I went looking for detailed info on what could this mean to the engine function. This video was just excellent......no vacuum on the upstroke (no fuel and air into the crankcase), no pressure in the crankcase on downstroke to move the mixture into the combustion chamber and lots of air leakage. Repaired the hole......my leaf blower is just fine again. Thank you
Hi. I bought a brand new CF MOTO 450RS motorcycle and from new, gear changes were rough and it had vibrations. After the first service, the bike felt a lot worse, and engine was over heating sporadically. At 1400klm I realised when the dealer said that it was normal and I had taken the bike back 6 times, back to the dealer, I investigated the problem and found the dealer was filling the oil to below the empty level. When I toped up the oil, it took 750ml to get it to the full line. That's 1/3rd oil missing since new. In the cf moto user manual it states that the oil should only be filled to below the low line, but in doesn't say if this when the bike is on the side stand or upright on a service stand. Turns out they were filling it up on the service stand in the upright, and those instructions were for the bike being on the side stand. So dealer was filling my bike and some others short of oil. Engine now sounds rough compared to new bike and I am hearing a slight ratting sound. Can you please tell me, during this crucial run in period, what is the potential damage to the engine and gear box? I think during the crucial 1000klm run in period not having enough oil to meet even the bottom line of the low indicator mark would have caused damage, but dealer said no, it's o.k..
I had a 1983 Yamaha YZ125 dirt bike that had worn crank seals. One day, the engine RPM suddenly increased to a very high level un-commanded and I had to press down on the kill switch for several seconds before it finally died out. After that, it never started again until I sold it to somebody who went through the whole engine with a fine tooth comb and replacing all worn parts.
this is the first video closest to the truth of the reason a 4 stroke will never make as much horsepower as a 2 stroke of the same displacement ! now watch the video again and again and listen as its told pressure is forced higher than the incoming air trapped by the reed valve as the piston is making the compression in the crank case 1st that is much higher than the air than enters the carburetor ...we call this condition supercharging by no other name .and when he stress the fact that it is a sound wave that blocks the supercharged air from escaping the exhaust port as the piston now traps the supercharged intake air/fuel and compresses this mixture the 2nd time into the combustion chamber right before the spare plug explode the mixture with no telling how much more force than a 4 stroke of the same displacement but i will say that Yamaha knows along with KTM , Husqvarna and GasGas who has their MC 125 two stroke making 40 horsepower that is roughly 20 horsepower that Honda's pro CRF150 R motocross racer that on a good day barely makes a claimed 23 horsepower while the GasGas is in the 1st turn while the Honda is still clearing the gate after a little cuttie turns the 5 sec board sideways skipping off the track wearing a skirt and top she out grew years ago
Once upon a time that may have been true about 2 strokes having more power than a 4 stroke of the same displacement but not anymore. A yamaha 250 f can make more hp than a yz 250 . The reason is the,compression ratio. Follow the 2 cycle on a complete cycle again and observe that as the piston rises it doesnt start true,compression until the piston completeley closes,all the intake , transfer and exhaust ports which is about halfway of the upward intake , exhaust then compression stroke, AND,the power stroke,has the same situation , it only has a,2/3 or so true,power stroke before a giant hole opens up and bleeds off any expanding gases that could act upon the piston face if it didnt. Altho the 2 stroke has primary compression in the crankcase area under the piston and has a power stroke every time at TDC or twice as many as a four stroke it doesnt have the efficiency of a four stroke in the Carnot cycle or PVT ( pressure - volume - temp relationship which has a total duration ( some can have more than 180 degrees,of compression or power but to some extant ot is 180 on each . A higher compression ratio is a more efficient engine and doesnt waste the fuel as much and also has a better lubrication system than the total loss of burning it . However where the 2 stroke shines over the 4 stroke is power to weight. Very light, simple and cost effecrive do to simplicity and less parts to machine.
@@waynegarfield6607 why are you here ? your total ignorance of engines is pathetic ..i am an apprentice of the late Hideo "Pops Yoshimura the most famous tuner of all times knowig more than you anyone else ..as now i have all his knowledge and YOU DONT
@@waynegarfield6607 what you said is impossible simply because 4 stroke dirt bikes are not supercharged but 2 stroke dirt bikes are internally supercharged by the double action of their pistons that was said to be true by Hideo "Pops" Yoshimura , the man who invented honda's very 1st 2 stroke called the Elsinore ..ever heard of one ? they are the bikes that make that Braaaaping sound when your being passed and yelled at "get outa myway bitch"
Aslında iki zamanlı motora temiz hava enjeksiyonu ve yakıt enjeksiyonu olmak üzere iki enjeksiyon ilave edilse pistonun üst noktasından uygun bir yerden önce hava sonra yakıt enjekte olsa dolayısıyla piston yakıt girişi iptal olsa 4 zamanlı motorlardan çok daha avantajlı olur.yani motorda yakıt girişini iptal edip yerine pistonun üst noktasına iki minik mesela 2 milimetre çapında giriş biri hava enjeksiyon ötekide yakıt enjeksiyon olması çok daha iyi bir yanma sağlar.piston yukarı çıkarken henüz egzoz girişi kapanmadan önce temiz hava, egzoz girişi kapanınca ardından yakıt enjekte olursa mükemmel bir yanma olur.Tabi bunlar aynı anda görev yapmalı ve ikisininde geri tepme ventilleri olmalı . Bunlar hava ve yakıtı çok basınçlı bir şekilde püskürtmeli.Bilmem anlatabildimmi.
After watching this it explains whe I'm having trouble with my Morini Franco 50cc, I had low compression and bought a cheap Chinese replacement piston which is slightly higher at the crown and now I think that I should have paid more and got an original one.
@@danielfrazier840 Thanks for the replay, but I defo should have bought a suitable piston, I've damaged the Nikasil plating on the cylinder and it will cost me plenty to put right.
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Now you are certified yamaha technician!! You could be hired at any dealer tomorrow!!
Weight and power is always a concern of mine!!
As I struggled with a non functioning small 2 stroke engine on my leaf blower ( suddenly after 3 or 4 years of good service), and trying everything I could think of, I stumbled into a video about a unit with many of the same history/repair points as my unit. That engine was repaired by tightening of loose bolts, cylinder to block, which was permitting air leaks. I checked my engine - rock solid but while there I chanced to remove the blind end plastic crankcase cover. Nasty hole in this cover so I went looking for detailed info on what could this mean to the engine function. This video was just excellent......no vacuum on the upstroke (no fuel and air into the crankcase), no pressure in the crankcase on downstroke to move the mixture into the combustion chamber and lots of air leakage. Repaired the hole......my leaf blower is just fine again. Thank you
I wish these guys could link da toos for advertising n sheeeit
Brilliant. Please share more videos like this, these make a TON of difference to one's ignorance..
Hi. I bought a brand new CF MOTO 450RS motorcycle and from new, gear changes were rough and it had vibrations. After the first service, the bike felt a lot worse, and engine was over heating sporadically. At 1400klm I realised when the dealer said that it was normal and I had taken the bike back 6 times, back to the dealer, I investigated the problem and found the dealer was filling the oil to below the empty level. When I toped up the oil, it took 750ml to get it to the full line. That's 1/3rd oil missing since new.
In the cf moto user manual it states that the oil should only be filled to below the low line, but in doesn't say if this when the bike is on the side stand or upright on a service stand. Turns out they were filling it up on the service stand in the upright, and those instructions were for the bike being on the side stand. So dealer was filling my bike and some others short of oil.
Engine now sounds rough compared to new bike and I am hearing a slight ratting sound. Can you please tell me, during this crucial run in period, what is the potential damage to the engine and gear box? I think during the crucial 1000klm run in period not having enough oil to meet even the bottom line of the low indicator mark would have caused damage, but dealer said no, it's o.k..
They skipped overheating and air leaks from worn crank seals .
I went to Yamaha marine school then . Excellent 👍
Thanks for sharing
I had a 1983 Yamaha YZ125 dirt bike that had worn crank seals. One day, the engine RPM suddenly increased to a very high level un-commanded and I had to press down on the kill switch for several seconds before it finally died out. After that, it never started again until I sold it to somebody who went through the whole engine with a fine tooth comb and replacing all worn parts.
@@vigorousboredom7016 yes..Lean out can cause piston seizures crank rod bearing fail from no oil and not lean mixture.
Excellent video
Glad you liked it
I believe that 2 strokes are closer to musical instruments than machines. To me the sound of a crisply jetted one ripping through the gears is music.
This video so old that in my headphones one side plays music the others the guy talking. Only realized half way through 😂
Yeah I only left my right ear bud in. No music. Perfect. Lol
I had to adjust the audio balance so I didn't have to listen to that annoying music from the 80's or 90's. I prefer videos like this with no music.
Very nice.
Cool video. Watched the whole thing as I’m about to buy a YZ250!
Good choice!
this is the first video closest to the truth of the reason a 4 stroke will never make as much horsepower as a 2 stroke of the same displacement ! now watch the video again and again and listen as its told pressure is forced higher than the incoming air trapped by the reed valve as the piston is making the compression in the crank case 1st that is much higher than the air than enters the carburetor ...we call this condition supercharging by no other name .and when he stress the fact that it is a sound wave that blocks the supercharged air from escaping the exhaust port as the piston now traps the supercharged intake air/fuel and compresses this mixture the 2nd time into the combustion chamber right before the spare plug explode the mixture with no telling how much more force than a 4 stroke of the same displacement but i will say that Yamaha knows along with KTM , Husqvarna and GasGas who has their MC 125 two stroke making 40 horsepower that is roughly 20 horsepower that Honda's pro CRF150 R motocross racer that on a good day barely makes a claimed 23 horsepower while the GasGas is in the 1st turn while the Honda is still clearing the gate after a little cuttie turns the 5 sec board sideways skipping off the track wearing a skirt and top she out grew years ago
Once upon a time that may have been true about 2 strokes having more power than a 4 stroke of the same displacement but not anymore. A yamaha 250 f can make more hp than a yz 250 . The reason is the,compression ratio. Follow the 2 cycle on a complete cycle again and observe that as the piston rises it doesnt start true,compression until the piston completeley closes,all the intake , transfer and exhaust ports which is about halfway of the upward intake , exhaust then compression stroke, AND,the power stroke,has the same situation , it only has a,2/3 or so true,power stroke before a giant hole opens up and bleeds off any expanding gases that could act upon the piston face if it didnt. Altho the 2 stroke has primary compression in the crankcase area under the piston and has a power stroke every time at TDC or twice as many as a four stroke it doesnt have the efficiency of a four stroke in the Carnot cycle or PVT ( pressure - volume - temp relationship which has a total duration ( some can have more than 180 degrees,of compression or power but to some extant ot is 180 on each . A higher compression ratio is a more efficient engine and doesnt waste the fuel as much and also has a better lubrication system than the total loss of burning it . However where the 2 stroke shines over the 4 stroke is power to weight. Very light, simple and cost effecrive do to simplicity and less parts to machine.
@@waynegarfield6607 why are you here ? your total ignorance of engines is pathetic ..i am an apprentice of the late Hideo "Pops Yoshimura the most famous tuner of all times knowig more than you anyone else ..as now i have all his knowledge and YOU DONT
@@waynegarfield6607 what you said is impossible simply because 4 stroke dirt bikes are not supercharged but 2 stroke dirt bikes are internally supercharged by the double action of their pistons that was said to be true by Hideo "Pops" Yoshimura , the man who invented honda's very 1st 2 stroke called the Elsinore ..ever heard of one ? they are the bikes that make that Braaaaping sound when your being passed and yelled at "get outa myway bitch"
Just found your channel and Subscribed. Very nice video. Thanks
Awesome, thank you!
Aslında iki zamanlı motora temiz hava enjeksiyonu ve yakıt enjeksiyonu olmak üzere iki enjeksiyon ilave edilse pistonun üst noktasından uygun bir yerden önce hava sonra yakıt enjekte olsa dolayısıyla piston yakıt girişi iptal olsa 4 zamanlı motorlardan çok daha avantajlı olur.yani motorda yakıt girişini iptal edip yerine pistonun üst noktasına iki minik mesela 2 milimetre çapında giriş biri hava enjeksiyon ötekide yakıt enjeksiyon olması çok daha iyi bir yanma sağlar.piston yukarı çıkarken henüz egzoz girişi kapanmadan önce temiz hava, egzoz girişi kapanınca ardından yakıt enjekte olursa mükemmel bir yanma olur.Tabi bunlar aynı anda görev yapmalı ve ikisininde geri tepme ventilleri olmalı . Bunlar hava ve yakıtı çok basınçlı bir şekilde püskürtmeli.Bilmem anlatabildimmi.
After watching this it explains whe I'm having trouble with my Morini Franco 50cc, I had low compression and bought a cheap Chinese replacement piston which is slightly higher at the crown and now I think that I should have paid more and got an original one.
It'll be fine back the timing of some if it starts pinging
@@danielfrazier840 Thanks for the replay, but I defo should have bought a suitable piston, I've damaged the Nikasil plating on the cylinder and it will cost me plenty to put right.
Which 2 stroke engine is that they are demonstrating? What was it used in and what was the displacement
Jet ski engine
@@blueyhis.zarsoff1147 cc?
People are so smart man
Can’t learn anything with that music
Listen to it in stereo the music is mainly on the left channel the dialog is in the right channel.
Why do not put exhaust port lower than intake port?
... you are not smart...😂
2 Strokes are such garbage