You didn't run this low on oil???? Most likely leaking spots are; leaking down from the dip stick tube base, crank case split, low oil warning switch (if it has one), or oil filter adapter. If it's v-twin could be the breather valve between the two jugs behind the carb. all of these could leak down thinking you crank case seal is leaking??? General stuff to look for overheating would be cooling fins on the jugs (head cooling fins dirty or full of grass reducing air flow over the head or heads (which keep the engine cool enough to prevent lock up on air cooled engines) plugged or Flywheel air fins broken off.

Hello no this wasn't ran with no oil , the leak only started after I adjusted valves. I'm not sure that the leak is because it is getting too hot or not, but it certainly doesn't leak till it hot and then it really really leaks I did notice the filler pipe was lose? But when I was watching the leak it did defo look like it was coming out that seal. Shall try running it again tomorrow. I had running it with the black case off and I think this was why the filler was lose. May try again now I have put the case back and report my findings cheers

Could the oil be leaking out the valve cover and then running down so it appears to be coming out the bottom seal?

"I had running it with the black case off and I think this was why the filler was lose"

Well that is a sure way to ruin the engine. You do realize that "Black Cover" is instrumental in cooling? Read another thread on that.

Walt Conner

No this was only ran that way for 30 seconds, just enough to get warm and piss all the oil out of the seal. It is definatly the seal it's coming out of! I put everything back and ran it for about 30 seconds again and the same thing happened. I can see it pissing out of the seal! My question is could this be heat or pressure build up or is it likely I just didn't do the seal properly. It just never leaked before I did the valves it just had a starting issue. The machine only has 24 hrs on it but is five years old. It's really doing my head in. Any help please!

jules - might try running the engine briefly after "cover" is properly installed - with the crankcase oil dipstick loose or removed. This should relieve any internal pressure buildup.

If seal does not leak then, look for crankcase breather problems or such.Excessive Crankcase pressure buildup can also come from worn/damaged piston rings.
If seal still leaks with dipstick open, disassemble to CLOSELY chk seal lip condition (easy to damage during assy) or put in backwards (also sometimes possible).Also CLOSELY check finish of crankshaft surface where seal runs- only takes a minor scratch to allow a leak...

post back with results...

Yeah I replaced seal from underneath last time, will do the job this time by taking engine out and sump off. Anyone know of a good D I Y? Thanks alot everyone so far

I can send you a PDF copy of the Service Manual IF you like. Hope you haven't damaged the crankshaft seal surface. Address below, put in proper format and remind me, model number and what you want.

Walt Conner
wconner5 at frontier dot com

That would be great Walt. It's a Countax c300h model number 280H07 type 0112E1 code 050421ze
My email is julesrules32@hotmail.co.uk

I think Walt wants YOU to contact him, not vice versa.

Cheers for that Walt, top man!

Ok have now stripped down engine taken sump off, now it looks like the crank has been grinding down the back of the sump like its been pulled back by the drive belts is this possible if say the belts were to tight? And would just a new sump work or will it need a new crank as well?

To: Jules rules: Jules, take your engine to somebody who knows how to repair it, before you really mess it up!
It is quite evident, from your questions about things, that you should seek professional help, before you get any deeper into engine destruction!
I say this, to save a lot of monies that you will surely need to spend, after your feeble attempts to "fix" your engine! Rusty Jones

At this point it would be helpful for you to post some pictures of the damaged sump and of the crankshaft journal that bears on the sump.
And it is not going to be a simple matter of "damaged sump" either.
While it is "possible" the damage you see has been caused by overtensing the belt, it is also possible that what you see may have been caused by contaminated lube oil, or oil not changed often enough. Unless you have a very good reason to suspect a too tight belt contributed to the damage, the other crankshaft journals are probably damaged also (from contaminated oil).
Pictures would help here.

I dought it from the belt being too tight being it has tensioner? My guess also would Contamination also. Dust/dirt, grass, makes sand paper. Sand paper or fine sand particles in the sand gring away in the grease or oil at metal parts.

oil leak or with over greasing, the excess oil/grease that ozzzed out collects dust (fine sand in the dust)the oil/grease holds the dust and grinds away any metal it touches. IMO oil leaks if not fixed should be cleaned regularly and greasing should be less pumps and not more IMO?

Hello again, thanks for all the constructive comments, I say it looks like the cutter belt could have done this damage. I say this as I inherited the mower (24 hrs use) and when I first used it the cutter belt kept coming off. Well when I read the mannuel I noted the lever to tension it was intentioned however when I tensioned the lever it was rock hard, tight. Now when I look at the sump it is worn only on one side of the hole the one on the side as if the belt was really tight and and there is some scuffs on shaft itself however I don't think it very bad. I'm hoping to just replace the sump and re tension belt. This is the reason the first time I put the bottom seal in from underneath it didn't work. I have not much experience of lawn mowers but I have rebuild a good few car engines. Surely I am capable of this work?

Well, If you say it ain't so bad then I agree with you but I sure wish I could see a picture.
If you put up a picture I'll give you 1,000 words. Ain't that right Walt?