Piston rails

[bebeav]

After i know now that i blew my rings, i removed the exhaust and look into the engine. i found a lot of rails on the piston.

does it mean also that the cylinder will be rail?

does it have been cause by then ring or the ring may be intact and it just because the piston is now too "railed"?

ALP
Beav

[bebeav]

forgot to put the pic

[Rocketman]

You wont know for sure until you take it apart, but most likely there will be "rails", or groves in the cylinder walls.

[secluded]

is that a blaster or a 250r??

yeah i almost know there will be grooves on the inside, what happened? i know on my 2 stroke, leaning it out and bad bearings causes my comression loss/blowing it up.

[bebeav]

which bearing? crank?

let see some pic of my piston and interior of my cylinder
and try to tell me what was the cause of my blown engine.

[bebeav]

pic n° 2

[bebeav]

pic n° 3

[bebeav]

pic n°4

[Kev250R]

Seen that before, looks like you seized it! The first 250R re-build I did was on my '83 250R and on that piston one side looked like the one in your photos, the other looked fine! The trike was still running when I tore the engine down, the machine shop which cleaned-up the cylinder for me said if I had kept riding it, it would have only been a matter of time before it seized all the way.

I'm going to be tearing that same engione down again over the summer (blew the cylinder base gasket, just like last time) I'm kind of curious to see what this piston will look like.

BTW I'm still using the first one as a door-stop!

--Kevin

[bebeav]

what do you mean by "seized it"

i don't know a lot of technical word in english yet. i'm learning also in this way

but if it's what i think : the piston cannot move??? like i can't kick it it would still at the same position??

if it's what you called seized, it's not that cause i was able to kick it again and again since i take off the cylinder.

if it's not that could you explain plz

ALP
Beav

[2strokepower]

it looks like it may have broken a ring and got on top of the piston. if thats the case you will need to get the head cleaned up to.

unfortunately i will be going through my entire motor. i think the crank bearings have seized up. good luck with yours.

[bebeav]

no the ring wasn't broke and still in where they sit.
but i think my piston melted
cause when i pass my finger on the wall of the cylinder it seem that there only litlle dent, really small dent but also some iron part over the wall.

i'm gonna see a honda shop tomorow to evaluate the damaged.

ALP
Beav

[bebeav]

can the jetting of the carb may be a cause of this engine damage??

ALP
Beav

[Kev250R]

As with most things in life, the term "seized" can mean more than one thing, yes most of the time when people talk about seizing-up a motor it means that it seized-up tight, basically the piston "welded" it's self to the cylinder wall!

However it is possible to get the piston so flippin' hot that it just starts to melt and begin the process of fusing to the cylinder wall, IMHO given what you said about feeling an iron part on the cylinder wall is probably really molten aluminum sticking to the cylinder wall. A good machine shop should be able to machine all that away though so I wouldn't be too concerned by it.

And in answer to your last question, yes not having your trike properly jetted will definitely cause the sort of damage you've described, in fact I've been chasing a jetting problem on one of my 'R's for quite some time. Seeing your photos has re-inspired me to get to the bottom of my jetting problem.

HTH and don't feel bad, a couple of years ago I cold-seized the brand-new engine in my '84 250R in one trip due in part to improper break-in, wrong jetting, wrong grade of fuel, and probably other stuff I'm forgetting (it was an expensive lesson). BTW cold-seizing is where the piston heats-up faster than the cylinder (need an example? Put an un-opened can of soda in your freezer, similar concept). When I pulled that piston out it had four lines going down the skirt of the piston. That one's also a door stop ;)

--Kevin

[dunerash]

Looks like he had an airleak(base gasket?).. We have a bunch of blaster pistons that look that way, were using them for garage ashtrays, but door stops are another great idea.. When you were running the bike hard, did it come right back down to idle? Or did the revs stay high without your hand on the throttle?

[bebeav]

it's most like it's come back to idle when i was at WOT.
i'm going to change all my top end gasket.

i asked the question for the jetting cause my little bro start to play with my carb after i clean it up. he told me that he didn't touch the jetting screw but all the other one. i think he was lying. damn little bro you cost me an arm :)

how can i re-jet my carb now?? didn't do that since i'm born.
i need a teacher here, gotta learn again today.

i'm going to a honda shop right now. to know how much it will cost me.

thx for all the great information you gave me guys.

gonna come back with price and details of the damaged later today

ALP
Beav

[N8S250r]

What was your spark plug gapped at?

If your plug is not gapped right it will create too much heat and cause a blown engine.

It is important to check your plug gap before you put it in even if it is a new plug. someone could have dropped it while it was in the box and it could have messed up the gap.

Thats how i blew my engine.... STUPIDITY! the stupidest, littlest thing caused ,my brand new rebuild to die.:bash: :eek:

[bebeav]

what do you mean by "gapped at"

another new word in my covabulary

ALP
Beav

[wheel-E 200x]

id say it was way lean.maybe there was an airleak in the carb boot. i couldnt see both sides of the piston but it coulda been cold seized from not letting it warm up. you can tell cold seize bc the majority of gouges and scratches will be on four sides of the piston. question, right after it died could you kick it over? if you couldnt then awhile later you could id say cold seize. thats what happened to my rm125.

[bebeav]

i also so think now that's more like an air leak. maybe at the boot but it may also be the base gasket like the shop said.

i'm gonna put a new piston .75 overbore with new rings and gasket. need to overbore it a .75 cause it's already at .50

and still hopping that's not a crank ceal.

i'm gonna know it in 3 weeks. gotta get some cash to buy all the part needed. just bought the bike and i'm broke down now.

it will cost me aprox 250-300$ Can

thx for all the information guys. now let's get some cash

ALP
Beav

[N8S250r]

Well... what kind of plug is in the motor first off... the name and the number;)

[bebeav]

DR9ES

ALP
Beav

[N8S250r]

Yuck! :( .... Never run that again, use a NGK br8es from now on;)... thats what i run and it works great for all weather:headbang: :headbang:

[bebeav]

sorry BR9ES. i think it's colder than the BR8ES. I'm i right???

is it better or the same? or i really should get some BR8ES spark plus


ALP
Beav

[Kev250R]

Good point about the cylinder base gasket Dunerash, I forgot to mention that when I tore the mill in my '83 250R down for the first time and the piston was partially seized was caused by a blown cylinder base gasket. It dosen't seem to take very much of an air leak to cause a piston to seize.

--Kevin

[N8S250r]

yea your right with the temp., a br9es will work fine but the mediocre plug is br8es and its basically good for any weathered day. However in the winter time a br7es is a good choice cause its colder out and a br9es is good if your gonna be runing in... lets say desert weather:D hopefully that helps a little w/ what plug to run in what conditions.:headbang:

[bebeav]

ok so i can use the plenty of br9es i got lolll

i think my father bought me like 15 spark plug cause i tough it would be usefull with a 2 stroke engine heheh

thx for all the info guys

ALP
Beav