@NoMoreC2 THANKS. I have about a 1000 more moped videos you can watch on all phases of these little bikes. I hope you find them usefull and thanks again.
my piston ring out a honda cr 125 (just got new piston and re boar ran it in v well) using it out on track and it dies.. get it home and its ok again .. then it dies again .. there are similar marking as in ya vid nothing deep but my piston ring is well tight !! i have re oiled it and shaved some of the groove where i think its tightest and am going to put it back together tomoro
I like the videos but honestly there's just so many causes for piston seizure. Like water in the fuel, carbon deposits on exhaust port of cylinder, there's even ways to figure out what went wrong just by looking at scoring PATTERNS, it's crazy...
@yz100f Shaving the head is supposed to give you more compression , but you have to know exactly what to do , because if you take too much off and have piston-slap when the motor gets up to speed, you will destroy the piston and the engine. I have never done it personally, but I would use a compression gauge and take very good measurements for clearance before I risked it. ALSO gas is watered down crap these days and detonation is a very big problem with crummy pump gas. RH DSD
no piston wash on the top means lean jetting or hot engine,
damage to the center of the top of the piston means detonation. from lean jetting, bad gas, water in gas, improper timing....
damage to the exhaust side of the piston were it erodes the piston edge towards the top ring means lean.
scoring means water in fuel. that scoring will show up on the intake side usually. scroing all around but a good looking piston top usually means cold start revving.
@xcr800imp damage to the exhaust side of the piston were it erodes the piston edge towards the top ring means lean.... av got that and it looks like it has effected th way the ring moves (not so freely )
I dont know what you are doing for gas/oil, but my old school lessons taught me to cap off the oil injector, and make the bike a full race old style premix bike at 40 or 45 to 1.........I could make that damaged head into a super high compression head. DSD, check my blog on the 2 stroke bike I made, the video is uploaded.....I get to 35 mph in 1st gear at over 7500 RPMs and 50 in 2nd
my wrist pin did the same thing. my h2o head/piston was messed up. lucky cylinder was perfect, but after the shop put in a new head and piston the clip broke. haha just my luck
the thing why you are geting so much stuck pistons and why this one almost seazed after 3 minutes is you are running too hot. Switch to a number cooler plug, get a smaller main jes (68 or 70) and put in a high temeraure oil like repsol or total 2 stroke oil for scooter. Itl fix your problem
Oh no, my frend, with 120cc and a 28mm carburator you do not use a 70main jet. Im not sure, but i guess he uses about 130. A colder plug may do solve the problem.
@warezvz all good except for you would want a bigger main jet size to run it richer not leaner, less fuel more air = hotter , more fuel less air = cooler
A very helpful and clear video series.Well done
NoMoreC2 2 weeks ago
@NoMoreC2 THANKS. I have about a 1000 more moped videos you can watch on all phases of these little bikes. I hope you find them usefull and thanks again.
DIOSpeedDemon 2 weeks ago
my piston ring out a honda cr 125 (just got new piston and re boar ran it in v well) using it out on track and it dies.. get it home and its ok again .. then it dies again .. there are similar marking as in ya vid nothing deep but my piston ring is well tight !! i have re oiled it and shaved some of the groove where i think its tightest and am going to put it back together tomoro
myidisjustfine 2 months ago
what exactly are seize marks? how can they occur? can you still use the piston and/or the cylinder is if you repair it with the marks remaining?
thanks
TheAnigai 3 months ago
This has been flagged as spam show
I'm sorry but you have no idea what you are talking about.
rc300xs 4 months ago
I like the videos but honestly there's just so many causes for piston seizure. Like water in the fuel, carbon deposits on exhaust port of cylinder, there's even ways to figure out what went wrong just by looking at scoring PATTERNS, it's crazy...
sbdem1986 5 months ago
thx usefull
bajdlek 9 months ago 2
I have an Airsal T6 Racing 70cc cylinder kit, the piston has Airsal written on it, next to the Airsal is a arrow.
The arrow is supposed to point down.
z0ne276 9 months ago
hey what about shaving the head to boost compression does that help at all^
yz100f 10 months ago
@yz100f Shaving the head is supposed to give you more compression , but you have to know exactly what to do , because if you take too much off and have piston-slap when the motor gets up to speed, you will destroy the piston and the engine. I have never done it personally, but I would use a compression gauge and take very good measurements for clearance before I risked it. ALSO gas is watered down crap these days and detonation is a very big problem with crummy pump gas. RH DSD
DIOSpeedDemon 10 months ago
@yz100f You can change the shape of the inside of the head, look up "squish band"
LordFabs 2 months ago
thanks man, your video is really helpful!
silentstorm77 1 year ago
blow by will show up as blackening on the surface of the rings.
scoring all around on a new engine means improper break in, or possible incorrect piston to wall clearance. also can be lack of lube.
xcr800imp 1 year ago 2
no piston wash on the top means lean jetting or hot engine,
damage to the center of the top of the piston means detonation. from lean jetting, bad gas, water in gas, improper timing....
damage to the exhaust side of the piston were it erodes the piston edge towards the top ring means lean.
scoring means water in fuel. that scoring will show up on the intake side usually. scroing all around but a good looking piston top usually means cold start revving.
xcr800imp 1 year ago
@xcr800imp damage to the exhaust side of the piston were it erodes the piston edge towards the top ring means lean.... av got that and it looks like it has effected th way the ring moves (not so freely )
myidisjustfine 2 months ago
great videos
TakSunn 1 year ago
Watched all 3 videos. Very helpful. Hope you revisit the issue.
tjharris81 2 years ago
I dont know what you are doing for gas/oil, but my old school lessons taught me to cap off the oil injector, and make the bike a full race old style premix bike at 40 or 45 to 1.........I could make that damaged head into a super high compression head. DSD, check my blog on the 2 stroke bike I made, the video is uploaded.....I get to 35 mph in 1st gear at over 7500 RPMs and 50 in 2nd
sonyshooter 2 years ago
you need to do plug chops, correct fuel/air mixture 14.7/1air ....stockimetric ratio
+ - on your main jets
WILLY8035 2 years ago
Comment removed
WILLY8035 2 years ago
my wrist pin did the same thing. my h2o head/piston was messed up. lucky cylinder was perfect, but after the shop put in a new head and piston the clip broke. haha just my luck
slipin808 2 years ago
the thing why you are geting so much stuck pistons and why this one almost seazed after 3 minutes is you are running too hot. Switch to a number cooler plug, get a smaller main jes (68 or 70) and put in a high temeraure oil like repsol or total 2 stroke oil for scooter. Itl fix your problem
warezvz 2 years ago
Oh no, my frend, with 120cc and a 28mm carburator you do not use a 70main jet. Im not sure, but i guess he uses about 130. A colder plug may do solve the problem.
R1ISCOOL 2 years ago
i was talking on a 50cc engine what do you need to do
warezvz 2 years ago
@warezvz all good except for you would want a bigger main jet size to run it richer not leaner, less fuel more air = hotter , more fuel less air = cooler
702dirtrider 1 year ago
cool and pretty helpful
roketm4n 2 years ago