Engine blown

[ginge511]

Hi all

1st post in a while.

Anyway last week me dang engine on me rs 125 blew

So I've recently dropped the engine out of me bike and had a look for myself.

When I've been looking at it I took the cylinder head off and it looked like this...

http://img292.imageshack.us/img292/3286/dsc00184yy0.jpg[/i]

So I've recently cleaned it up and all isd nice and smooth again.

Now i get to the piston itself and it's chomped up to say the least...

http://img355.imageshack.us/img355/1716/dsc00143mm5.jpg

And this....

http://img292.imageshack.us/img292/8587/dsc00144ve1.jpg

So I'm about to order a new piston head and rings but as i took it off i had a look at the conrod and It's really wobbly, like nearly an inch left and right and i could also push it down a little bit.

Now i need to know what i have to do to renew the bearing for the conrod?

Any ideas please, as I'll need to splitt the engine to get to it

Beginners look very much needed.

Any elp greatly appreciated .

Thanks

**edit PG to show pics**

Edited August 7, 2008 by ginge511

[jabcrosshook]

Images no worky.

[Guest philgale]

sorted.....make sure you use the actual image address, if you look at the URL you were using scroll down and you see the "direct link" that shows the picture and not just a thumbnail of the pic in a web page...

all sorted now tho

oh....i think there in the right order

[Guest]

to be honest if there is that much damage to the piston and that much play in the crank/conrod the bore must be pretty well scored and possibly worn out of true ... i dont think it is really worth the time and effort and cost to change all these parts i would suggest sourcing another engine if possible it may cost a little bit more but in th elong run it may be for the best ..

with the parts consider the price of gaskets and the time that will be spent

you will be looking at

new piston

Barrel either rebored/honed

Piston rings

Big end bearings ( cranck to conrod)

Little end gudgeon pin

Little end bearings

and then you still not sure on why the engine went bang ( well looking at the pics lack of oil/lubrication is one conclusion )

[ginge511]

I've been thinking the same thing latly mate.

But if i do go for another engine, what other engines fit into an aprilia rs 125cc 2000 model?

Other then another rs 125cc engine?

[Fozzie]

I've been thinking the same thing latly mate.

But if i do go for another engine, what other engines fit into an aprilia rs 125cc 2000 model?

Other then another rs 125cc engine?

 

The joys with motorbikes is that if you find an engine similar in size then it could be possible to make your own supports. Or just buy a bigger engine from Rotax. I think they do a 50hp single cylinder 600cc engine that should fit. Give the rs a good kick I think

[Bill_on_a_bike]

I've been thinking the same thing latly mate.

But if i do go for another engine, what other engines fit into an aprilia rs 125cc 2000 model?

Other then another rs 125cc engine?

 

The joys with motorbikes is that if you find an engine similar in size then it could be possible to make your own supports. Or just buy a bigger engine from Rotax. I think they do a 50hp single cylinder 600cc engine that should fit. Give the rs a good kick I think

 

Can't wait for the police to pull you on your L plate, with a straight four busting out either side of the fairing.

[Fozzie]

I've been thinking the same thing latly mate.

But if i do go for another engine, what other engines fit into an aprilia rs 125cc 2000 model?

Other then another rs 125cc engine?

 

The joys with motorbikes is that if you find an engine similar in size then it could be possible to make your own supports. Or just buy a bigger engine from Rotax. I think they do a 50hp single cylinder 600cc engine that should fit. Give the rs a good kick I think

 

Can't wait for the police to pull you on your L plate, with a straight four busting out either side of the fairing.

 

I'd never put a straight 4 in an RS. The frame couldnt take it. The RS250 has 60Hp so I'd try to keep the new engine no more than a 2 cylinder with no more than 60hp. And if the police pull me over it would be an interesting conversation but as long as the bike is restricted it wouldnt be any hassle.

[Guest]

why not fix what you have and then pass your test and sell it. At the moment the bike has scrap value only....with a motor in it and sorted you can get your money back.

there is a reason there are lots of differences between the 125 and the 250...brakes being a major one....youll find a 250 motor is way too quick and youll overshoot every corner

pass your test then buy a big bike, you wont regret it.

where are you btw?? here doesnt help

[Fozzie]

Quick question....How old is that engine??? Judging from the pictures its a fair few years old and done ALOT of miles.

[rosszx9r]

this isn't too hard to repair and on a 125, shouldn't take long. you've done the hard work by getting the engine out the frame!

the conrod should move side to side but shouldn't move up and down at all. when checking it, make sure the conrod is in the middle of the crank with equal movement either side, then try to move it up/down. if you feel any up/down movement, you'll have to strip the engine. it's probably a shell type bearing that comes in two halfs. it needs oil to make it work!

buy a haynes manual and it's really easy. a gasket set is probably going to set you back £100 for everything. piston ~£30. rebore ~£80. bearings ~£50

remember that if you rebore the engine, you'll need an oversized piston. this will give a little extra power (as will decoking the engine)

it looks like the engine has overheated and had a lube failure. once rebuilt, you need to strip and clean the carb making sure it's all set up correctly, then check the oil pump meticulaousy.

good luck!