Haha I thought I messed my weedeater engine up yesterday cause it got SO hot the the plastic shrouding started burning after 10 minutes of use! So I let it cool and today I am going to richen it up a little bit. I think it was running WAY to lean.
Streetlimit what is your oil to gas ratio. How long have u owned this bike. Has this ever been rebuilt. What happened when it failed. What kind of riding was done during the last few mins of operation?
here is a scneraio for you, i have a 1991 cr125R and it had a failure today. the piston has score marks on it BELOW the ring groove and has scored the cylinder on the exhaust SIDE ONLY intake side looks fine. what would you say about my problem. Dr. Bike
@DIOSpeedDemon-ive got a yamaha rx 135.the OEM piston seized so i put an .5mm oversize piston into it.ran the bike in nice n slow.after a couple of days i noticed that when the bike got hot the power started dying,the exhaust wasnt emitting any smoke whatsoever(oil pump working) and the exhaust note got a little silent.any idea what the problem could be?
My yz250 twostroke, had an OEM piston put in with a new crank. and 10 hours later after breaking it in right. it seized on me. i took it apart and the piston had broke off into many pieces at the bottom and the piston rings welded themselfs into there grooves. what the hell happened? besides oviously it got hot..
@Markey427 Let me look at the piston with a picture and I could tell you. Sounds like your spun a bearing which caused 500 degree heat in about 6 minutes. The piston will seize at a little over 425 degrees. better yet send me a video or a picture of all the parts and the case bearings and I probable could tell you. RH DSD
@DIOSpeedDemon Sounds like he didnt measure his clearances, piston expanded slightly bigger than its bore, the tolerances may have been too tight, or he ran it on straight gas or a really lean premix, but i doubt it was a crank bearing, if it was a crank bearing then the rings wouldnt be melted to the piston, and it would have just siezed and not broken to pieces, but i guess anythings possible haha
@Markey427 iF the piston seized, you have to rebuild the top and bottom end. Sounds like a spun crank bearing. Easy to fix but you just cannot seize the engine , replace the piston and expect it to run right. RH
Always run your bike through several heat cycles before doing any riding after a top end rebuild. Oh, and when you spend time trying to get the top end back on to the piston (it's aggravating) make sure you have your gaskets on and in place hahaha. I did this my first time. :P
My 50cc two stroke siezed a while ago, a piece of the nicazil thing inside "melted" into the side of piston, and it has ugly scratches on the other side. What went wrong?
@bayyagg is it hard to do this or fairly simple?I just got my first 2 stroke and I will probably be rebuilding the top end next summer depending on the compression
Just make the NEW engine at LOW compression first by using a THiCK head gasket, after such time the new piston and rings seated properly in BLOCK, then u could do replace it w/ thinner gasket for high compression.
i got a 2 stroke engine water cooled,radiator but oil it is used too much b y the 2 strokes engines so it cannot be used to cool down the engine because of that
however better cooling liquid i use it is antigel and not only it does not freeze in winter time it also dont boil that fast as water or air cooled engines
and the antigel it is also oil like wich means that it help grease the parts of your water pump instead of causing corosion like water does or causing dust intake like air does
hey just 2 tell u this , i learned this in college in my small engine class ,a liquid cooled engine will run at around 180 f and a air cooled engine will run at around 400 f ,, just taught you'd like 2 know that
ya, not 400. I don't let my air cooled 4 or 2 strokes get over 270-280. My water cooled 4 strokes like right around 200-210. Only engine I ever killed with heat was had a RC car runnin on Nitro fuel and it ran away. When I caught it upside down the engine was at 320 and it had siezed.
I hope you don't get paid to work on other peoples machines!
blacklabmustang1 1 month ago
long. pauses. between. talking.
thegenrl 2 months ago
Did he have a choke bore with the wrong piston in it?
kruz310 6 months ago
Haha I thought I messed my weedeater engine up yesterday cause it got SO hot the the plastic shrouding started burning after 10 minutes of use! So I let it cool and today I am going to richen it up a little bit. I think it was running WAY to lean.
wheely132 9 months ago
Streetlimit what is your oil to gas ratio. How long have u owned this bike. Has this ever been rebuilt. What happened when it failed. What kind of riding was done during the last few mins of operation?
fattony123082 9 months ago
here is a scneraio for you, i have a 1991 cr125R and it had a failure today. the piston has score marks on it BELOW the ring groove and has scored the cylinder on the exhaust SIDE ONLY intake side looks fine. what would you say about my problem. Dr. Bike
streetlimitz89 11 months ago
@DIOSpeedDemon-ive got a yamaha rx 135.the OEM piston seized so i put an .5mm oversize piston into it.ran the bike in nice n slow.after a couple of days i noticed that when the bike got hot the power started dying,the exhaust wasnt emitting any smoke whatsoever(oil pump working) and the exhaust note got a little silent.any idea what the problem could be?
MrKoolkev123 1 year ago
I DONT WANT YOUR SHITTY INSURANCE ALLSTATE !!
chunkmanshaun 1 year ago
My yz250 twostroke, had an OEM piston put in with a new crank. and 10 hours later after breaking it in right. it seized on me. i took it apart and the piston had broke off into many pieces at the bottom and the piston rings welded themselfs into there grooves. what the hell happened? besides oviously it got hot..
Markey427 1 year ago
@Markey427 Let me look at the piston with a picture and I could tell you. Sounds like your spun a bearing which caused 500 degree heat in about 6 minutes. The piston will seize at a little over 425 degrees. better yet send me a video or a picture of all the parts and the case bearings and I probable could tell you. RH DSD
DIOSpeedDemon 1 year ago
@DIOSpeedDemon Sounds like he didnt measure his clearances, piston expanded slightly bigger than its bore, the tolerances may have been too tight, or he ran it on straight gas or a really lean premix, but i doubt it was a crank bearing, if it was a crank bearing then the rings wouldnt be melted to the piston, and it would have just siezed and not broken to pieces, but i guess anythings possible haha
M0T0RID3R559 7 months ago
@Markey427 iF the piston seized, you have to rebuild the top and bottom end. Sounds like a spun crank bearing. Easy to fix but you just cannot seize the engine , replace the piston and expect it to run right. RH
DIOSpeedDemon 1 year ago
Always run your bike through several heat cycles before doing any riding after a top end rebuild. Oh, and when you spend time trying to get the top end back on to the piston (it's aggravating) make sure you have your gaskets on and in place hahaha. I did this my first time. :P
cr199 1 year ago
Damed!!!
ALIHEMIKALI 1 year ago
My 50cc two stroke siezed a while ago, a piece of the nicazil thing inside "melted" into the side of piston, and it has ugly scratches on the other side. What went wrong?
trepxtrechi 1 year ago
haha you race a moped!!!. you know your cool when
swabbster3 1 year ago
i have a vespa pk engine would you say point arrow to the back instead of exhaust only the manual says arrow to exhaust port
hanghoodiescum 1 year ago
TIP: for 2 stroke engine!
when puting a new set of piston & ring, round up the corners of intake and exhaust ports, using a steel file!
Rounding up the corners prevent damage to piston rings and cylinder!
bayyagg 2 years ago
That is excellent advice. RH DSD
DIOSpeedDemon 2 years ago
@bayyagg is it hard to do this or fairly simple?I just got my first 2 stroke and I will probably be rebuilding the top end next summer depending on the compression
rideskisallday 2 months ago
@rideskisallday
Good luck for rebuilding that engine!
Just make the NEW engine at LOW compression first by using a THiCK head gasket, after such time the new piston and rings seated properly in BLOCK, then u could do replace it w/ thinner gasket for high compression.
bayyagg 2 months ago
mayb some1 could build a 2t engine but with oil cool
bradman158 2 years ago
i got a 2 stroke engine water cooled,radiator but oil it is used too much b y the 2 strokes engines so it cannot be used to cool down the engine because of that
however better cooling liquid i use it is antigel and not only it does not freeze in winter time it also dont boil that fast as water or air cooled engines
and the antigel it is also oil like wich means that it help grease the parts of your water pump instead of causing corosion like water does or causing dust intake like air does
:)
aqasenior 1 year ago
In a 4cycle air cooled engine what kinda oil will make it run cooler think or thin?
5 stars
roboman79 2 years ago
hey just 2 tell u this , i learned this in college in my small engine class ,a liquid cooled engine will run at around 180 f and a air cooled engine will run at around 400 f ,, just taught you'd like 2 know that
bombjas6924 2 years ago
most air cold engines cylender temps should be a around 200 400 its just to hott
fmftrx300ex 2 years ago
ya, not 400. I don't let my air cooled 4 or 2 strokes get over 270-280. My water cooled 4 strokes like right around 200-210. Only engine I ever killed with heat was had a RC car runnin on Nitro fuel and it ran away. When I caught it upside down the engine was at 320 and it had siezed.
emptytruckdriver 2 years ago