to scrap or not????

[jamesw]

Hi guys I have a problem with my stump grinder and i hope that someone on here has a good soloution, idea or just a laugh at my expense.

 

It has been a mare over the winter with the machine i have sorted out the electrics and starter moter, and now she turns over well and runs. Took it out after this work today to test her on a smallish willow stump. I will be honest i had a restless sleep over it, and today she let me down just like i thought she would! It ran fine for a little while then she started losing power and dogging out on the stump. Addmitedly the teeth are in need of a sharpen but didn't feel like the teeth belt kind of power loss. Then oil/petrol mix started leaking from round the exhaust port and slightly from the exhaust. No smoke. Oh and it is running only on one cylinder, which i tested with the ht leades.This has happened before and was made better by a new spark plug. however this spark plug has only done around 6hrs max:sneaky2: So now i am stuck wondering what to do:confused1: Is there anyone out there that this makes sense to and who could give me some sound advice. Pics of the machine to follow

 

Oh and i am ready for the burn it and scrap it brigade and the should have got a rayco blah blah:lol:So thanks in advance for any info

[Omniata]

Do you know anyone that's a mechanic that could take it apart and have a look

 

God forbid if it's cracked inside

[Albedo]

I'm no expert but I enjoy trying to work these things out specially when its not my machine as this removes the pressure.

 

We have unburned fuel from the combustion chamber being forced out of the exhaust port. Then thru the exhaust gasket to the outside.

 

So possible causes:

 

1)Too much fuel introduced to combustion chamber.

2) incomplete combustion

3) May be more possible causes

 

Maybe both of above, So my theory is on the fuel delivery side - carburetor

 

I'm sure you'll get a more comprehensive answer from someone, but could be just a carb tune up and new plug (which you did already) ? Might be worth testing for a spark then checking HT leads if not already done.

Edited February 9, 2010 by Albedo

[jamesw]

Yeah was thinking along your lines paul, and i am going to get the ht leads checked! Was advised last time by a friend that it could be some kind of seal or ring:confused1: any thoughts?

[Graham]

Another scenario. Possibly valve guide seal worn allowing oil to drain past the valve. Plug fouls up = running on one cylinder.

 

When it does run on both cylinders does it smoke?

[jamesw]

hi graham

I had just found Kohlers online manuals and they have suggested worn piston rings. Is that the same thing or not? Yeah i think there was a hint of white smoke to start with then disappeared when i put the plug in last time. But none today.

 

I think after reading up a bit its either the ht leads or as you said the piston ring valvy thing:lol:

[Graham]

Could be rings. Oil passing the piston and fouling up.

 

These type of engines are really easy to strip and take a peek at. Make sure it's not electrical before to save unnecessary work.

[jamesw]

Is there anyone on the the forum who deals with this kind of machinary for a living and lives fairly nearby? At present i am having to rent a machine for my next stump day, a week thursday! and just feel that i would rather spend that money on getting my machine A1. Any takers i will drive around two hours away for a good quick service:thumbup:

[gensetsteve]

It seems to have a dipstick. Which would indicate four stroke but you mention oil fuel mix. Do you put straight petrol in it.

[Albedo]

My little bit of knowledge comes mainly from stripping a landy engine, so I can picture diesel better in my head. Graham knows more than me I think

 

Anyway the valves he refers to I think go up and down (tapits, rocker gear controlling this) all hitched up to timing belt, and allow exhaust gases out and air? in, all in sync with the exploding fuel in the combustion chamber, driving the piston down.

 

 

He's looking at oil getting in - fouling the plug - no combustion - fuel blasted out of exhaust port - I think?