My old Yamaha Engine.

[Ricky]

So basically I asked if I could have the old engine from my Yamaha and the mechanic happily gave it me so I thought I'd do what the mechanic didn't do and strip it down and see where the fault is and I took and the barrel, etc off and first thing I saw that didn't look right was the piston...

http://imageshack.us/a/img5/6685/bfti.jpg

http://imageshack.us/a/img819/1403/j3oe.jpg

http://imageshack.us/a/img35/1668/iov9.jpg

When I hold the piston and spin the engine round it doesn't make that clunking noise like it did previously?

Did I just waste 723 quid on something as simple as that?!

[eastanglianbiker]

no you didnt because all the missing bits of piston have gone down into the bottom of the engine and lots of it would of been ground into dust making any oil left like a grinding paste that passed through all the bearings and oil ways possibly blocking some as well

[Ricky]

Stupid question but how can I tell between dead bearings and non dead bearings?

[Joeman]

that well and truly knackered mate...

new engine was the best option.

[eastanglianbiker]

a dead bearing will rumble/make a noise as you spin it where as a new/good bearing will be silent,or it will have more play/torerence in it than it should have

[Ricky]

If I split the crank case and investigate the bearings and they're okay, clear any debris at the bottom should it be okay?

[eastanglianbiker]

i wouldnt be trying to use it again but it might be worth holding onto just for bits like the clutch and gearbox out of it should you ever need them

[Ricky]

I was thinking more for a go kart

I might just sell the undamaged parts on it try and make some money back

[Guest]

DAMN.. you did a good job of that one ricky

Perhaps if you strip the engine down, flush it all through etc

you may be able to save the engine, replace the piston, and should be good to go..

would be a good engine for go kart, or keep the engine for spare/spare parts...

[Fozzie]

Break the engine into its key components and lay it out nice and easy so you can put it back together again.

As it's only a 125 there aren't that many bearings. You could go through the whole engine realligning parts and rebuilding it steadily to produce an as new motor. Will cost a couple of hundred quid in bearings and bits but you could do it.

Would be a good learning experience I suppose

[klingelton]

Break the engine into its key components and lay it out nice and easy so you can put it back together again.

As it's only a 125 there aren't that many bearings. You could go through the whole engine realligning parts and rebuilding it steadily to produce an as new motor. Will cost a couple of hundred quid in bearings and bits but you could do it.

Would be a good learning experience I suppose

 

I'd give my left tooth for a project such as that - alas i don't have the space and the wife wouldn't allow me to strip an engine on the kitchen work surface.

It's like a lego set for adults, you'd be beaming if you got it running again!

[Ricky]

Break the engine into its key components and lay it out nice and easy so you can put it back together again.

As it's only a 125 there aren't that many bearings. You could go through the whole engine realligning parts and rebuilding it steadily to produce an as new motor. Will cost a couple of hundred quid in bearings and bits but you could do it.

Would be a good learning experience I suppose

 

That's a great idea

Cheers dude

[acting_strange]

Break the engine into its key components and lay it out nice and easy so you can put it back together again.

As it's only a 125 there aren't that many bearings. You could go through the whole engine realligning parts and rebuilding it steadily to produce an as new motor. Will cost a couple of hundred quid in bearings and bits but you could do it.

Would be a good learning experience I suppose

 

That's a great idea

Cheers dude

 

As far as bearings are concerned you do not necessarily have to buy from the honda dealer...get them out and have a look on their sides where you should find a series of numbers. These you can then use to find a match and possibly get them cheaper...

[Joeman]

You might struggle pushing some of the bearings out though.. unless you have a bearing press laying about at home!!?

Personally, i would strip it down to be nosy, clean up the parts and flog the lot on eBay.

let someone else pay for new bearings

[acting_strange]

You might struggle pushing some of the bearings out though.. unless you have a bearing press laying about at home!!?

Personally, i would strip it down to be nosy, clean up the parts and flog the lot on eBay.

let someone else pay for new bearings

 

In the 30 yrs that I was fixing cars, vans and anything else that had an engine I never had a bearing press....but I did have a heat gun and lots of patience...even something to align a crank with after splitting it can be made up at home with some common sense...

[Tiggie]

keep it for practising oil changes!

[acting_strange]

keep it for practising oil changes!

 

Cruel but truthful....lol

[Ricky]

keep it for practising oil changes!

 

[Joeman]

You might struggle pushing some of the bearings out though.. unless you have a bearing press laying about at home!!?

Personally, i would strip it down to be nosy, clean up the parts and flog the lot on eBay.

let someone else pay for new bearings

 

In the 30 yrs that I was fixing cars, vans and anything else that had an engine I never had a bearing press....but I did have a heat gun and lots of patience...even something to align a crank with after splitting it can be made up at home with some common sense...

 

You mean the same kind of common sense that makes sure the engine has oil??

[Stu]

Personally it's not worth the hassle also how does the barrel look? Also the crank could need a re grind if any material has got behind the bearing

Strip clean and sell

[acting_strange]

You might struggle pushing some of the bearings out though.. unless you have a bearing press laying about at home!!?

Personally, i would strip it down to be nosy, clean up the parts and flog the lot on eBay.

let someone else pay for new bearings

 

In the 30 yrs that I was fixing cars, vans and anything else that had an engine I never had a bearing press....but I did have a heat gun and lots of patience...even something to align a crank with after splitting it can be made up at home with some common sense...

 

You mean the same kind of common sense that makes sure the engine has oil??

 

Good point .... well made....but we were all young once...

[Fozzie]

Crucially check behind the bearings where the grinding effect takes place when shards of metal get free...

If your bike went pop and stopped it's unlikely it got around. If you did mile after mile with it running then you could be in trouble.

But if you got away with it and you can check it's always worth it for the experience it gives.

You just need some circlip pliers, heat gun and maybe a small blow torch, and if you can make one or find one a bench press. I managed to get one for £40 off a mate, 10 tonne one too!

If you don't already I have a haynes manual for a YZF in my garage somewhere. Will try to find it for you if you don't have one.

[Ricky]

Crucially check behind the bearings where the grinding effect takes place when shards of metal get free...

If your bike went pop and stopped it's unlikely it got around. If you did mile after mile with it running then you could be in trouble.

But if you got away with it and you can check it's always worth it for the experience it gives.

You just need some circlip pliers, heat gun and maybe a small blow torch, and if you can make one or find one a bench press. I managed to get one for £40 off a mate, 10 tonne one too!

If you don't already I have a haynes manual for a YZF in my garage somewhere. Will try to find it for you if you don't have one.

 

Thanks a lot for the reply

I'm going to check the state of everything first because all it's potentially going to be used for is a go kart or a project of some sort

The barrel is in great condition there's no scratches or damage to it which is surprising when looking at that piston

I'll be sure to send you a PM if the damage isn't to bad and then try and rebuild it

Stupid question but my bike is fuel injected so would I have to buy a new one of them or can I try and find an adequate carburettor or does it not work like that?

[Fozzie]

You can make it carbed, as long as the spark timing is correct then there is no issue.

The Rieju RS3 125 uses a carbed version of the engine. Makes more power so if you can source the electrics and carb for one of those you will be in business.

[Ricky]

You can make it carbed, as long as the spark timing is correct then there is no issue.

The Rieju RS3 125 uses a carbed version of the engine. Makes more power so if you can source the electrics and carb for one of those you will be in business.

 

As the engine won't be used using the same electronics as on my yamaha I'll have to convert it to carbs won't I?

New to this stuff and especially electrics

I'll split the case tonight inspect the bearing make a video and some pictures and start a thread later on

If the damage is going to be loads then I'm going to just sell the working parts if not ill be borrowing your manual